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Biosecurity Assessment and Seroprevalence of Respiratory Diseases in Backyard Poultry Flocks Located Close to and Far from Commercial Premises
Abstract
Raising backyard chickens is an ever-growing hobby in the United States. These flocks can be a substrate for respiratory disease amplification and transmission to commercial facilities. Five hundred fifty-four chickens from 41 backyard flocks were sampled in this study. ELISA kits were used to detect antibodies against avian influenza (AI), infectious laryngotracheitis (ILT), Newcastle disease (ND), infectious bronchitis (IB), Ornithobacterium rhinotracheale (ORT), Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS). All visited flock owners answered a biosecurity questionnaire that assessed biosecurity measures. The questionnaire revealed that backyard poultry owners lack simple biosecurity measures such as use of dedicated shoes, their chicken sources are unreliable, and few of them benefit from veterinary oversight. Only one flock had a clear vaccination history against ND and IB. ORT, ND, IB, MS, MG, and ILT were the most seroprevalent in backyard poultry flocks with 97% (41/42), 77.5% (31/40), 75% (30/40), 73% (31/42), 69% (29/42), and 45% (19/42), respectively. The vaccinated flock was not considered in these calculations. When examining the distance between backyard flocks and the nearest commercial poultry facility, ND and MG were significantly more likely to be found in backyard flocks close to (<4 miles) whereas ORT was significantly more likely in backyard chickens located far from (>4 miles) commercial poultry. Birds purchased directly from National Poultry Improvement Plan hatcheries showed a reduced ND, MG, and MS antibody prevalence. Wearing dedicated shoes decreased MS antibody-positive birds. Finally, history of wild bird contact had a clear effect on an increased seroprevalence of NDV and MG. Serological results suggest that backyard poultry flocks have the potential to serve as a reservoir or amplifier for poultry respiratory diseases. The information generated in this project should direct extension efforts toward emphasizing the importance of small flock biosecurity and chick acquisition sources.
... Keeping chickens for hobby or small-scale commercial purposes, henceforth referred to as small chicken flocks (SCF), has become popular in European and North American countries [1][2][3][4]. Information on population size, structure, geographic location, animal husbandry, disease occurrence and disease management in Swedish SCF has remained limited while corresponding populations have received some attention in several other countries [3][4][5][6][7]. ...
... Keeping chickens for hobby or small-scale commercial purposes, henceforth referred to as small chicken flocks (SCF), has become popular in European and North American countries [1][2][3][4]. Information on population size, structure, geographic location, animal husbandry, disease occurrence and disease management in Swedish SCF has remained limited while corresponding populations have received some attention in several other countries [3][4][5][6][7]. ...
... Several studies have indicated that a variety of parasites and pathogenic organisms may be widespread among European and American SCF, some of which may cause respiratory infections [2,3,11,12]. In recent years, respiratory signs have become one of the most common complaints of SCF owners when they submit chickens for necropsy to the National Veterinary Institute (SVA) in Sweden. ...
Background
A growing number of people in western countries keep small chicken flocks. In Sweden, respiratory disease is a common necropsy finding in chickens from such flocks. A respiratory real-time polymerase chain reaction (PCR) panel was applied to detect infectious laryngotracheitis virus (ILTV), Avibacterium paragallinarum ( A . paragallinarum ) and Mycoplasma gallisepticum ( M. gallisepticum ) in chickens from small flocks which underwent necropsy in 2017–2019 and had respiratory lesions. Owners ( N = 100) of PCR-positive flocks were invited to reply to a web-based questionnaire about husbandry, outbreak characteristics and management.
Results
Response rate was 61.0%. The flocks were from 18 out of Sweden’s 21 counties indicating that respiratory infections in small chicken flocks are geographically widespread in Sweden. Among participating flocks, 77.0% were coinfected by 2–3 pathogens; 91.8% tested positive for A. paragallinarum , 57.4% for M . gallisepticum and 50.8% for ILTV. Larger flock size and mixed-species flock structure were associated with PCR detection of M . gallisepticum (P = 0.00 and P = 0.02, respectively). Up to 50% mortality was reported by 63.9% of respondents. Euthanasia of some chickens was carried out in 86.9% of the flocks as a result of the outbreaks. Full clinical recovery was reported by 39.3% of owners suggesting chronic infection is a major challenge in infected flocks. Live birds had been introduced in many flocks prior to outbreaks, which suggested these as an important source of infection. Following the outbreaks, 36.1% replaced their flocks with new birds and 9.8% ceased keeping chickens.
Conclusions
This study highlights the severity of respiratory outbreaks in small non-commercial chicken flocks and points to the need for more research and veterinary assistance to prevent and manage respiratory infections in small chicken flocks.
... Aussi, les basses-cours localisées en milieu rural à proximité d'élevages commerciaux sont plus à risque d'être séropositives pour certains agents pathogènes. Cela peut s'expliquer par la pression d'infection plus forte dans ces zones géographiques (41,132). Les résultats de l'article 2 (Partie 2) montrent également une différence significative des niveaux de prévalence en fonction des différents groupes d'élevages familiaux. ...
... Aussi, l'analyse des correspondances multiples (MCA) ainsi que le regroupement 806 hiérarchique (HCA) basé sur l'analyse des caractéristiques des élevages ont permis d'identifier trois 807 typologies différentes. 808Dans la littérature, certaines analyses sérologiques suggéraient déjà des infections courantes par NDV, 809 IBV, ILTV, MG, MS et ORT dans le secteur familial(27,41,45,130,132,135,136,139), mais peu d'études de 810 détections moléculaires d'un large panel d'agents infectieux respiratoires ont été réalisées à ce jour, hormis 811 chez la dinde et dans quelques études de co-infections respiratoires chez le poulet de chair 812(113,138,217,(252)(253)(254). AvP fait peu partie des agents pathogènes recherchés, pourtant c'est celui dont la 813 prévalence est la plus élevée dans les basses-cours françaises. ...
... Pour des basses-cours localisées dans des zones de forte production avicole, des facteurs de risques de diffusion du virus de l'IA ont été identifiés. En effet, en cas de foyer détecté au sein d'un élevage commercial, la forte densité animale, les manquements aux mesures de biosécurité, les différents flux associés à l'élevage (transports d'animaux, camions d'aliments, visite fréquente des services techniques et sanitaires), ainsi que la forte proximité géographique entre compartiments peuvent être autant de facteurs conduisant à la contamination depuis les élevages commerciaux vers les basses-cours(132,158).Il a été montré que la proximité géographique par rapport à un autre troupeau contaminé était un facteur de risque pour l'infection d'un élevage(159)(160)(161). En effet, plusieurs agents pathogènes (notamment respiratoires) peuvent être transmis par aérosols sur de longues distances comme cela a pu être montré dans l'apparition de cas de laryngotrachéite infectieuse dans la péninsule de Delmarva aux États-Unis(154). ...
Les élevages avicoles familiaux tels que les basses-cours rurales, les poulaillers urbains et les élevages de volailles de loisir sont un secteur important de la production avicole française. Estimés à 2,5 millions de propriétaires à ce jour, ces élevages sont suspectés de pouvoir transmettre des agents pathogènes aux élevages avicoles commerciaux. Dans cette étude, nous avons étudié le rôle des élevages avicoles familiaux dans la circulation et la transmission d'agents pathogènes aux élevages avicoles commerciaux. Afin de mieux caractériser les acteurs de la filière avicole familiale, une enquête participative nationale a été réalisée afin d'analyser les pratiques d'élevage et d'identifier différentes sous-populations. En parallèle, les prévalences de 14 agents infectieux à tropisme majoritairement respiratoire ayant un intérêt en santé publique et/ou animale ont été estimées. L'identification d'agents pathogènes comme marqueurs d'infection et de transmission a été effectuée en comparant les prévalences entre secteurs familial et commercial. Dans le secteur familial, cinq sous-populations ont été mises en évidence : les poulaillers urbains, les basses-cours traditionnelles, les poulaillers d'étudiants, les élevages familiaux "de compagnie", et les élevages de poules de race et de loisir. Des agents pathogènes comme Mycoplasma synoviae et Avibacterium paragallinarum, présentent une prévalence élevée dans les basses-cours, mais sont rarement identifiés dans les élevages commerciaux, ce qui pourrait en faire des marqueurs pertinents de transmission du secteur familial au secteur commercial. D'une manière générale, les résultats suggèrent un rôle limité des basses-cours dans la contamination des élevages commerciaux. A l'inverse, dans un contexte épizootique d'influenza aviaire, il a été montré que les liens humains entre secteur familial et secteur commercial représentaient un risque de contamination des basses-cours, conduisant ainsi à privilégier l'hypothèse inverse d'une possible contamination des élevages familiaux par les élevages commerciaux.
... Although several biosecurity measures are taken on commercial flocks, backyard or free-range production lack any veterinary protocol for disease prevention. In many cases backyard properties are located near commercial properties and may act as reservoirs for respiratory diseases to the commercial flocks, Derksen et al. (2018). ...
... A similar study performed in the Rio Grande do Sul State in southern Brazil has found 100% of properties with backyard chickens seropositive to IBV, reinforcing the spread of the virus in this type of property Santos et al. (2008). Reports have shown high seroprevalence eRBCA-2019eRBCA- -1225 for IBV in backyard chickens in Belgium, the USA and Mexico, Gutierrez-Ruiz et al. (2000); Haesendonck et al. (2014); Derksen et al. (2018). ...
... A serological survey performed in Pernambuco, Brazil found that 53.33% of the studied backyard birds were seropositive for MG with 100% positive properties, Sá et al. (2015). Studies also reported high seroprevalence for MS and MG in backyard flocks in Belgium, the USA and Argentina, Xavier et al. (2011);Haesendonck et al. (2014); Derksen et al. (2018). ...
Raising backyard birds is a common practice in Brazil, mainly in the countryside or suburban areas. However, the level of respiratory pathogens in these animals is unknown. We sampled two hundred chickens from 19 backyard flocks near commercial poultry farms and performed ELISA to Infectious Bronchitis Virus, avian Metapneumovirus, Mycoplasma synoviae and Mycoplasma gallisepticum. We evaluated the association between the predictive ability of ELISA and Hemagglutination-inhibition (HI)by comparing results from eight flocks positive to Mycoplasma gallisepticum on ELISA. Besides, we assessed essential biosecurity measures in the properties (multiple species birds, rodent control, hygienic conditions, and water quality for the bird`s consumption). We could access the vaccination program only on four properties; in three of them, the birds were supposedly vaccinated for IBV. Overall the properties had a poor score for the biosecurity measures, and the seroprevalence in backyard poultry flocks for IBV, a MPV, MS, and MG were respectively 87.5% (14/16), 89.5% (17/19), 100 (19/19) and MG 84.21% (16/19). We found low specificity and predictive value between ELISA and HI in MG analysis and a positive correlation between the presence of clinical symptoms and mean MG titers. Backyard chicken are pathogens’ reservoirs and pose a risk for the commercial poultry farms in the region, and further efforts of the governmental entities and private sector of poultry production should consider these information to avoid future economic losses.
... 23,30 The continuing rise in backyard poultry ownership in the United States has increased concern that many of these diseases may reemerge within backyard poultry populations, creating a threat of increased prevalence of these diseases nationwide. 9 Many studies have demonstrated that backyard poultry owners lack knowledge of biosecurity practices and are unwilling or unable to seek veterinary care for flock illnesses, further exacerbating the threat of disease within these populations (U.S. Department of Agriculture [USDA]. ...
... 6 Disease surveys of backyard flocks have described specific noninfectious and infectious diseases within this population. 9,18,35 Noninfectious causes of mortality, such as management-related, nutritional, and metabolic diseases in backyard flocks may occur as a result of widely varied breeding, housing, and husbandry practices. New flock owners may not be aware of general flock husbandry as well as changing and specific dietary needs of newly acquired laying hens or meat chickens. ...
... 6 These limitations can make raising backyard flocks a challenge to owners and may result in the manifestation of preventable diseases within these flocks. 9,33 Extensive research and management strategies have been implemented over time in the commercial poultry sector to reduce and eliminate infectious diseases within their flocks. Although infectious diseases are still common in commercial poultry, significant efforts are made by producers to prevent and control these diseases. ...
A comprehensive understanding of common diseases of backyard poultry flocks is important to providing poultry health information to flock owners, veterinarians, and animal health officials. We collected autopsy reports over a 3-y period (2015–2017) from diagnostic laboratories in 8 states in the United States; 2,509 reports were collected, involving autopsies of 2,687 birds. The primary cause of mortality was categorized as infectious, noninfectious, neoplasia or lymphoproliferative disease, or undetermined. Neoplasia or lymphoproliferative disease was the most common primary diagnosis and involved 42% of the total birds autopsied; 63% of these cases were diagnosed as Marek’s disease or leukosis/sarcoma. Bacterial, parasitic, and viral organisms were commonly detected, involving 42%, 28%, and 7% of the birds autopsied, respectively, with 2 or more organisms detected in 69% of birds. Our findings demonstrate the importance of educating flock owners about disease prevention and biosecurity practices. The detection of zoonotic bacteria including paratyphoid salmonellae, Campylobacter spp., Listeria monocytogenes, and Mycobacterium avium, and the detection of lead and other heavy metals, indicate public health risks to flock owners and consumers of backyard flock egg and meat products.
... Over the last two decades, several studies have focused on reporting biosecurity in small and backyard operations in developed countries (e. g., Derksen et al., 2018;Karabozhilova et al., 2012;Mur et al., 2016); however, this literature has yet to be summarized. To fill this research gap, the current study employed a scoping review (ScR) approach, which is a type of evidence synthesis aimed at providing a broad overview of available data, encompassing both quantitative and qualitative aspects (Peters et al., 2020(Peters et al., , 2015Sargeant and O'Connor, 2020), and aimed to answer the following research question: "What biosecurity practices are used in small and backyard farms raising livestock or poultry in developed countries?". ...
... Definitions of small, backyard, and hobby farms varied extensively between articles. Multiple authors used the words "small," "backyard," and "hobby" interchangeably Burns et al., 2011;Derksen et al., 2018;Van Steenwinkel et al., 2011), whereas others distinguished them (Halvarsson et al., 2022;Pires et al., 2019;Schembri et al., 2015). The criteria used by the authors to define "small," "backyard," and "hobby" farms are presented in Table 4. Fifty different definitions were analyzed, as two articles included both backyard and small farms, one included both small and hobby farms, and one article provided two different definitions for the poultry and swine farms, respectively (Nicholson et al., 2020). ...
... Additionally, biosecurity measures, such as footbaths, were implemented in only 15% of farms, compromising pathogen prevention. Another concern is that 90% of farms reported the presence of other domestic or wild animals, which increases disease risk, as observed by Derksen et al. (2018). ...
... The study revealed high seroprevalence rates for respiratory diseases in Thiès and Dakar, with Swollen Head Syndrome infection at 95%, attributed to inadequate biosecurity and high farm density. Derksen et al. (2018) reported similar issues, emphasizing the need for better control strategies. In contrast, lower prevalence rates have been observed in other parts of the world: 31.4% in Uruguay (Giossa et al., 2010), 8.0% in Argentina (Uriarte et al., 2010), 61.9% in layers and 31.7% in broilers in Grenada (Sharma et al., 2014), and 40% in Nigeria (Owoade et al., 2006). ...
The poultry sector in Senegal has experienced substantial growth due to increased private investment following the 2005 outbreak of Highly Pathogenic Avian Influenza (HPAI), leading to improved socioeconomic conditions and enhanced protein intake. Despite this progress, the sector faces significant health challenges from respiratory diseases, including Low Pathogenic Avian Influenza, Newcastle Disease, Infectious Laryngotracheitis (ILT), Swollen Head Syndrome (SHS), and Mycoplasmosis (Mycoplasma synoviae). To address these issues, an observational cross-sectional study was conducted in Dakar and Thiès, involving 20 randomly selected layer farms. Blood samples from 20 birds per farm (a total of 400 samples) were analyzed using indirect ELISA, and farm owners completed detailed questionnaires on biosecurity, vaccination, and disease management practices. Data were recorded in Microsoft Excel and analyzed with STATA software using logistic regression tests to explore relationships between seroprevalence and various variables. Results revealed high seroprevalence rates of 95% for Swollen Head Syndrome, 60% for Mycoplasmosis, and 25% for ILT. The study highlighted significant deficiencies in biosecurity and vaccination practices, with only 15% of farms using footbaths, and 80% experiencing vaccination failures due to poor-quality vaccines. Statistical analysis showed no significant influence of breed, age, or farming type on the prevalence of these diseases. These findings indicate critical shortcomings in current poultry health management practices in Senegal. The lack of effective biosecurity measures, such as the low use of footbaths and inadequate litter management, contributes to the spread of respiratory diseases. Additionally, the high prevalence of vaccination failures underscores the urgent need for improved vaccine quality and administration techniques
... Furthermore, over half of the flocks in our survey had food and water sources that could be accessed by wild birds and/or rodents, and concern expressed by keepers regarding contact with pests was not high. This is lower than 88% of backyard flock owners in California who reported contact between their flock and wild bird populations in another study, 16 but nonetheless represents a significant area for further education for flock owners to avoid potential spread of disease from wildlife reservoirs. Co-produced recommendations from attendees of a UK workshop and survey responses regarding AI regulations and guidance include clearer, more targeted biosecurity recommendations for backyard poultry flocks and suggest poultry suppliers and veterinarians as potential communication routes. ...
... Indeed, Papadopoulou et al., 18 on behalf of the UK government, asked British veterinary practitioners to remind their clients of the illegality of this practice to prevent disease transfer risk. A survey of backyard poultry keepers in France found that 41.6% of respondents were aware of Newcastle disease virus, while 96.7% were aware of AI. 11 A history of wild bird contact significantly increased the risk for Newcastle disease virus in backyard flocks in the United States 16 and in Ethiopia, 19 countries where the disease is endemic, suggesting that a focus on biosecurity measures would have more impact than a focus on feeding kitchen scraps. ...
Background
This survey investigated the housing, feeding, health and welfare of backyard chickens kept in the UK.
Methods
Information was collected via an online questionnaire active from May to July 2021. The survey asked about flock demographics, housing, diet, enrichment provision, if the flock was registered with the Animal Plant and Health Agency (APHA) and the reason, preventative health care and biosecurity, and the incidence and methods of euthanasia.
Results
The majority of flocks (48.8%) consisted of one to five birds, were located in rural areas (58%) and were kept as pets (77%) and/or for eggs (71.6%). Enrichment was provided by 78.4% of keepers. Most respondents (69%) were aware of the Animal Plant and Health Agency poultry registration scheme, with 32.8% being registered with the scheme. Kitchen scraps were fed by 29% of keepers. Veterinary services were used by 63.6% of keepers, although 4% said they struggled to find a veterinarian willing to treat backyard poultry. New additions to the flock were isolated by 70.2% of keepers.
Limitations
The survey was distributed through poultry‐specific Facebook groups and via chicken rescue centres, so it is not a truly random sample of backyard chicken keepers. All survey‐based studies have an inherent element of subjectivity.
Conclusions
The survey identified biosecurity, humane euthanasia training, veterinary training in backyard poultry medicine, and enrichment provision as areas where improvements can be made to improve poultry health and welfare and reduce the risks of infectious disease transmission.
... Newcastle disease was detected in backyard avian species raised without simple biosecurity measures located less than 6 km from commercial poultry facilities in the state of California, USA (40). In the present study, the nearest commercial poultry farm (in a straight line) is approximately 300 km from Araguaiana and 75 km from Cáceres (41) (data not shown); therefore, backyard poultry from these regions seem unlikely to have been infected as a result of proximity to commercial poultry farms. ...
... Interactions between wild birds and backyard poultry have clearly increased the seroprevalence of ND (40). Birds highly adapted to urban areas, such as pigeons (Columba livia) and other members of the family Columbidae, can also act as potential carriers and transmitters of diseases (45,46). ...
The Pantanal and Cerrado biomes in the state of Mato Grosso contain migratory bird sites in the municipalities of Cáceres and Araguaiana, respectively. The levels of avian influenza (AI) and Newcastle disease (ND) viral activity in backyard poultry at these sites are unknown owing to a lack of studies. Considering the risk of introduction of AI and ND to Brazil from migratory birds, as well as the importance of active surveillance in the detection and prevention of diseases for official control, monitoring in these poultry populations is faster, more practical and cheaper for official service veterinarians. The objective of this study was to verify the presence of AI and ND viral activity in backyard poultry reared near these migratory bird sites in the years 2016 and 2019. Serum samples and cloacal and tracheal swab samples collected from chickens, turkeys, quails, ducks and geese were evaluated by indirect diagnostic methods including enzyme-linked immunosorbent assay and haemagglutination inhibition tests and direct detection of viral sequences using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). No positive samples were detected by qRT-PCR.The frequencies of birds seropositive for AI and ND were 0.7% and 19.6% in 2016 and 0.5% and 17.2% in 2019, respectively, in Araguaiana and 0.8% and 32.3% in 2016 and 7.0% and 38.1% in 2019, respectively, in Cáceres. Antibodies belonging to AI subtypes H1, H4, H6 and H14 were identified in Cáceres in 2019. Spatial analysis showed an agglomeration of farms with seropositive poultry within the urban area of Cáceres, suggesting AI and ND virus activity in this area. This study showed no circulation of the notifiable AI subtypes H5 and H7 or the ND virus in backyard poultry raised around migratory bird sites in the state of Mato Grosso. The results of the present study support evidence indicating that the circulation of strains with low pathogenicity in urban areas enables backyard poultry to serve as a source of infection for other birds; thus, increased surveillance is necessary in this population.
... Considering that exotic and backyard birds can act as a source of virus infection for industrial poultry flocks (Alexander, 2001;Derksen et al., 2018), isolation of and studying NDVs (virulent or avirulent) present in exotic and backyard birds can also be beneficial in rooting the source of the NDVs found in commercial flocks. In this context, it is essential to note that just two amino acid changes in the NDV cleavage site of F protein can convert an avirulent strain to a virulent one (Alexander, 2001;Derksen et al., 2018). ...
... Considering that exotic and backyard birds can act as a source of virus infection for industrial poultry flocks (Alexander, 2001;Derksen et al., 2018), isolation of and studying NDVs (virulent or avirulent) present in exotic and backyard birds can also be beneficial in rooting the source of the NDVs found in commercial flocks. In this context, it is essential to note that just two amino acid changes in the NDV cleavage site of F protein can convert an avirulent strain to a virulent one (Alexander, 2001;Derksen et al., 2018). Table 7. ...
BACKGROUND: Newcastle disease virus (NDV) is an avian pathogen that infects various species of birds worldwide. Recurrent outbreaks of ND consistently occurring in Iran cause substantial economic losses each year. The Northeast region of Iran has an extensive commercial poultry industry and is also a big exporter of poultry products to other countries. Therefore, consistent and dynamic surveillance of the NDVs prevalent in this geographic region is very important in keeping the disease under control.
OBJECTIVES: The virulence of the virus is determined based on the sequence of Fusion (F) protein. However, though the Phosphoprotein (P) and Matrix (M) proteins of NDV are also involved in the evolution and pathogenicity of the virus, molecular evaluation of their genomic loci in the NDVs prevalent in Iran is limited. Here, we present data for the sequences of full length P and M gene belonging to an NDV that caused the ND outbreak of 2011 in the Northeast of Iran.
METHODS: The genomic sequences encoding full-length P and M proteins as well as that of F protein were amplified using PCR and sequenced by Sanger sequencing. The obtained sequences, plus their translated proteins were evaluated using various bioinformatic approaches. Such as homology and phylogenetic analyses.
RESULTS: Phylogenetic analyses based on P, M, and F genes clustered our isolate together with VII.I.I GenBank sequences from Iranian sources reported from 2011 to 2019, as well as with those reported from China. But, our isolate showed less homology to vaccine strains commonly used n Iran.
CONCLUSIONS: Our study shows that, in addition to the newly evolving sub-genotypes, VII.1.1 variants are still circulating in the region. The weak homology in determinant regions between this strain and those used for vaccine production needs to be considered in vaccination programs. Further, the persistent presence of NDV genotypes already prevalent in the Far East in Iran highlights the importance of biosecurity management and dynamic surveillance in controlling ND.
... Coinfections or secondary infections in diseases caused by viral pathogens such as ILTV may provide a more serious condition and lead to increased mortality [33,34]. Most reports of ILT mixed infections detected by molecular methods or the isolation of pathogens are associated with backyard flocks, although they have also been confirmed in commercial poultry [16,17,[33][34][35]. ...
... Coinfections or secondary infections in diseases caused by viral pathogens such as ILTV may provide a more serious condition and lead to increased mortality [33,34]. Most reports of ILT mixed infections detected by molecular methods or the isolation of pathogens are associated with backyard flocks, although they have also been confirmed in commercial poultry [16,17,[33][34][35]. ...
Infectious laryngotracheitis (ILT) is an acute, highly contagious infectious disease of the upper respiratory tract in chickens and other poultry species that causes significant economic losses in countries worldwide. Between 2017 and 2019, seven outbreaks of mild to severe respiratory disorders with high suspicion of ILT occurred in commercial and backyard poultry flocks in Slovenia. In all submissions, infection with ILT virus (ILTV) was confirmed by PCR, which is the first report of ILT in Slovenia. Circulating ILT strains were characterized by the sequence and phylogenetic analysis of two fragments of the ICP4 gene. Four strains—three detected in non-vaccinated flocks and one in a flock vaccinated against ILT—were identical or very similar to the chicken embryo–origin live virus vaccines, and the other three were closely related to Russian, Chinese, Australian, and American field strains and to tissue culture origin vaccine strains. As in other diseases, coinfections with other respiratory pathogens in confirmed ILT cases may cause a more severe condition and prolong the course of the disease. In our study, coinfections with Mycoplasma synoviae (7/7 tested flocks), infectious bronchitis virus (5/5 tested flocks), Mycoplasma gallisepticum (4/7 tested flocks), Ornithobacterium rhinotracheale (3/4 tested flocks), and avian pox virus (1/2 tested flocks) were confirmed, indicating the importance of these pathogens in the occurrence of ILT infections.
... Biosecurity, the set of measures taken to reduce the risk of disease transmission within or between populations, can be suboptimal or absent in these flocks. For instance, it is uncommon for small flocks to be vaccinated (6,7,8,9), and owners are often unaware of the vaccination status of their birds (9). Similarly, the use of simple hygiene measures, such as washing hands after contact with poultry, is also inconsistently applied; in Alberta, Canada (6), 13% of small flock owners reported washing their hands. ...
... The available information in the literature documents poor vaccination practices in small flocks (7,8,9,15). Despite the routine practice of in ovo vaccination for Marek's disease at Ontario hatcheries, only one-third of the owners who sourced birds from a hatchery indicated that their birds were vaccinated, and many did not know the vaccination status of their birds and chose to write an additional response other than ''yes'' or ''no.'' ...
As part of a two-year, disease surveillance project of small poultry flocks, owners of birds submitted for postmortem examination to the Animal Health Laboratory were asked to complete a questionnaire designed to gather information on the characteristics of the flock and its environment, how the flock was managed, and biosecurity measures used. A total of 153 unique questionnaires were received. Personal consumption of meat or eggs was the most common reason for owning a small flock (69.3%). Almost all owners (97.4%) reported having chickens on their property, while 21.6% had waterfowl, 15.7% had turkeys, and 15.7% had game birds. Nearly seventy percent (69.9%) of the flocks had some degree of outdoor access. For those with indoor access, the most common bedding material provided was soft wood shavings (70.2%). Kitchen waste or leftovers were offered to 65.3% of flocks, and well water was the most common source of drinking water (80.6%). For flocks with indoor access, dedicated shoes and clothes were used when entering or cleaning the coop by less than half of owners, and shoes were rarely disinfected before or after contact with the flock. Most owners (93.8%) reported washing their hands after contact with their birds, although only 48.3% reported washing their hands before contact. Among owners who sourced birds from a hatchery, only 36.8% indicated that the birds had been vaccinated and 21.1% were unsure if vaccines had been administered. Among owners using medication (60.5%), the use of antibiotics was common (60.9%). Overall, questionnaire responses describe a wide range of husbandry and biosecurity practices, often suboptimal, and point out the need for educational material for Ontario small flock owners.
... They are frequently involved in ILT outbreaks, and can be maintained in BYFs, which may serve as a reservoir for ILTV infection of nearby commercial flocks. 7,10,16 Recombinant viral vector vaccine options are ILTV genes inserted into a fowlpox virus (FPV) or turkey herpesvirus (HVT). Recombinant viral vector vaccines do not have the risk of regaining virulence; however, the level of protection is reduced when compared to MLV vaccines. ...
... MS and MG were the most common coinfections at 33% and 28%, respectively, and are commonly reported pathogens in BYFs. 7,12 Marek's disease at an early age can interfere with protection inferred from ILTV vaccination and makes the host more susceptible to coinfections. 8 Marek's disease is the most common cause of mortality in California BYFs and was a coinfection in 17% of cases in our study. ...
Infectious laryngotracheitis (ILT) can cause severe losses in backyard flocks (BYFs) and commercial poultry. The prevalence of ILT, the circulating strains of ILT virus (ILTV) in BYFs, and the correlation of disease in BYF and commercial operations, is largely unknown. Of 8,656 BYF submissions, 88 cases of ILT were diagnosed at the California Animal Health and Food Safety Laboratory System in 2007–2017. ILT diagnosis by year varied from 0.19% to 1.7% of the total BYF submissions, with the highest number of cases submitted from Amador and Riverside counties. Moderate tracheitis, conjunctivitis, and occluded tracheal lumen were commonly reported gross anatomic lesions. Microscopically, inflammation and edema were observed in the trachea, lung, and conjunctiva; 62 (70%) cases had intranuclear inclusion bodies (INIBs), with 10 cases containing INIBs only in conjunctival sections. To analyze the circulating ILTV strains and to differentiate between field and vaccine strains of ILTV, real-time PCR and sequencing of 996 base pairs of the infected-cell polypeptide 4 (ICP4) gene was performed on 15 ILTV-positive tracheal samples and compared to reference field and vaccine ILTV ICP4 sequences in GenBank. Fourteen strains were identical or closely related to the chicken embryo origin live virus vaccine strains, and one strain was closely related to a Chinese isolate, the USDA reference strain, and a vaccine strain. The presence of ILT in BYFs in counties with high commercial poultry concentrations demonstrates a risk for disease transmission and emphasizes the importance of continued surveillance and improved biosecurity in BYFs.
... Although the mortality of MS infection is not high, it can cause growth retardation, carcass downgrading, and egg production decline, significantly impairing poultry production and reproductive performances (Yadav et al., 2022). Moreover, MS may manifest as a coinfection alongside various bacterial or viral pathogens, thus causing substantial economic losses to the poultry industry (Derksen et al., 2018). Accurate and effective detection of MS is the prerequisite for identification, prevention, and control of the disease. ...
Mycoplasma synoviae (MS) is an essential pathogenic mycoplasma in poultry worldwide, posing a serious threat to the poultry industry's health. Timely detection is imperative for early diagnosis, prevention, and control of MS infection. Current laboratory methods for MS detection are generally complicated, time-consuming, and require sophisticated equipment. Therefore, a simple and rapid method is urgently needed. This study developed a novel real-time fluorescence-based recombinase-aided amplification (RF-RAA) technique for detecting MS nucleic acids, enabling target gene amplification within 20 min at 39°C. The RF-RAA outcomes are interpretable in 2 modalities: real-time fluorescence monitoring employing a temperature-controlled fluorescence detector or direct visual inspection facilitated by a portable blue light transilluminator. This method exhibits robust specificity, demonstrating no cross-reactivity with various common poultry pathogens, and achieves high sensitivity, detecting as low as 10 copies/μL for the standard plasmid. Seventy-one clinical samples of chicken throat swabs were detected by RF-RAA and real-time fluorescence quantitative polymerase chain reaction (qPCR) methods. The diagnostic coincidence rates of qPCR with RF-RAA (fluorescence monitoring) and RF-RAA (visual observation) were determined to be 100% and 97.2% (69/71), respectively. In conclusion, the RF-RAA method developed in this study provides a rapid and visually observable approach for MS detection, offering a novel technique to diagnosing MS infection, especially in resource-limited settings.
... Mycoplasma synoviae (MS) has been described as an important pathogen causing air sacculitis, infection synovitis and eggshell apex abnormalities (1)(2)(3), and is listed as a notifiable mycoplasma by the World Organization for Animal Health (WOAH) (4). MS infection can cause subclinical symptoms and lead to co-infection with Mycoplasma gallisepticum (MG), Newcastle disease virus (NDV), Infectious bronchitis virus (IBV), and other avian pathogens (5)(6)(7)(8). Rapid and accurate diagnosis is necessary to monitor MS infection especially after vaccination. Diagnostic methods for MS include bacteriological isolation, serological assays and molecular detection (9). ...
Mycoplasma synoviae (MS) is an economically important pathogen in the poultry industry. Vaccination is an effective method to prevent and control MS infections. Currently two live attenuated MS vaccines are commercially available, the temperature-sensitive MS-H vaccine strain and the NAD-independent MS1 vaccine strain. Differentiation of vaccine strains from wild-type (WT) strains is crucial for monitoring MS infection, especially after vaccination. In this study, we developed a Taqman duplex real-time polymerase chain reaction (PCR) method to identify MS1 vaccine strains from WT strains. The method was specific and did not cross-react with other avian pathogens. The sensitivity assay indicated that no inhibition occurred between probes or between mixed and pure templates in duplex real-time PCR. Compared with the melt-based mismatch amplification mutation assay (MAMA), our method was more sensitive and rapid. In conclusion, the Taqman duplex real-time PCR method is a useful method for the diagnosis and differentiation of WT-MS and MS1 vaccine strains in a single reaction.
... These agents can be easily transmitted vertically or laterally from bird to bird. Sub-clinical MG infections can show clinical chronic respiratory disease in chickens and infectious sinusitis in turkeys (7,30). Additionally, birds infected with MG and MS are more prone to getting infected with other viral and bacterial agents such as IBV and Escherichia coli (18). ...
This study reports the coexistence of two S1 mutants of GI-13 (4/91-like) Infectious Bronchitis Virus (IBV) and Mycoplasma gallisepticum (MG) in a backyard poultry flock that had non-vaccinated 30 broiler chickens and four turkey pullets. Serum samples and tracheal swabs were taken from the chickens and turkey pullets showing respiratory signs. Serum antibody levels were measured using commercial ELISA kits against IBV, Avian Influenza Virus (AIV), Newcastle Disease Virus (NDV), Avian Metapneumovirus (AMPV), MG, Mycoplasma synoviae (MS), and Ornithobacterium rhinotracheale (ORT). Additionally, tracheal swabs were tested for AIV serotypes H5, H7, and H9, NDV, IBV, AMPV, MG, MS, Pasteurella multocida, Avibacterium paragallinarum, and Bordetella avium by circular amplification technology (CAT). Anti-MS,-IBV,-MG,-NDV,-AMPV, and-ORT IgG antibodies were detected in some chicken sera, while anti-NDV,-MG,-MS, and-ORT IgG antibodies were detected in turkey sera. All avian tracheal swabs were positive for MG. However, IBV was only detected in chicken tracheal samples tested by CAT. The IBV strains were genotyped by sequencing a part of the S1 glycoprotein gene. The alignment analyses of two isolates showed 99.35% and 98.69% nucleotide similarities and 99.02% amino acid similarities with the 4/91 IBV vaccine and field strains. Two mutants showed 99.35% nucleotide and 100% amino acid sequence identity to each other. The turkeys and chickens in the flock had MG and MG/IBV co-infections, respectively. Consequently, the presence of mutants of 4/91 (GI-13) IBV genotypes and MG found in backyard poultry could be a potential epidemiological source for commercial flocks in poultry integrations.
... Today, geographic information software (GIS) is commonplace and has been utilized for infectious disease risk analysis and surveillance (Colby et al., 2003;Paul et al., 2016), including mapping of IBV outbreaks (Aleuy et al., 2018) and extraction of geospatial data in relation to infectious outbreaks (Derksen et al., 2018). Environmental factors such as the vegetation of surrounding landscape have been previously reported to buffer air particles, including airborne IBV particles around poultry sites (Adrizal et al., 2008) and in urban areas (Burley et al., 2011;Janhäll, 2015). ...
... According to Ishfaq et al. (2020), use of inactivated bacterins is safer than using live vaccines to prevent chicken respiratory lesions and reduce vertical or horizontal transmission of the disease as the spreading of both MG and MS is due to both horizontal and vertical transmission. Both the strain involved and the stage of infection (from 3-4 weeks in the acute phase to decline in the chronic phase) may have an impact on the transmission rate in eggs (Derksen et al. 2018). These mycoplasmas can also spread horizontally by direct or indirect contact, aerosol transfer, introduction of contaminated objects, or contaminated personnel (Viviana et al. 2020) Numerous serological assays, including HI, ELISA and rapid serum agglutination tests, are used most frequently (OIE 2018) to estimate MG or MS antibodies. ...
AB S T RA C T A large number of poultry farms around the world have been shut down during the last few years due to avian Mycoplasmosis, especially those where chickens and turkeys were raised. Therefore, the main goal of this study was to investigate the possibility of eradicating the disease by immunizing one-week-old chicks and turkey poults against Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) using an inactivated single dose or a combined vaccine. In this study, a total of 280 one-week-old Specific-Pathogen-Free chicks were divided into four groups to evaluate their immune response following vaccination. Chicks of group 1 (n=60) were given inactivated MG vaccine, those of group 2 (n=60) were given inactivated MS vaccine. Chicks of group 3 (n=120) received combined inactivated MG+MS vaccine, while birds of group 4 (n=40) served as control. After three weeks, the chicks were administered with the booster dose of the respective vaccine. Similarly, 60 turkey poults of one week in age were divided into two groups: Poults of group 1 (n=50) received combined inactivated MG+MS vaccine, while those of group 2 (n=10) were kept as control. The booster dose of vaccine in group 1 birds was given after 4 weeks. The immune responses of vaccinated chicks and turkey poults were measured by HI test, ELISA and challenge test. The results of this study revealed that the combined inactivated MG+MS vaccine adjuvanted with Montanite ISA70 was more effective against Mycoplasma synoviae and Mycoplasma gallisepticum in chickens and turkey poults than the individual inactivated vaccine and there was significant difference in the group of turkey poult vaccinated with combined inactivated MG-MS in ELISA test.
... Within this context of a lack of information, our finding constitutes the first investigation on the disease prevalence within the backyard chicken population in this country. The results of our study provide evidence of a high prevalence of avian diseases in backyard chickens, which has the potential to serve as a reservoir or amplifier of avian diseases that might affect commercial poultry [53,54]. The high prevalence detected in our study is chiefly the result of the extensive farming system characterized by poor sanitary conditions, continuous exposure of chickens to free-range environments and wild birds, and bringing together different species and ages in the same place, all of which, due to the lack of any vaccination and biosecurity measures, increase the transmission of disease between birds. ...
Background and Aim
Raising backyard chickens is a common practice in Morocco, mainly in rural or periurban areas. Constraints due to devastating avian diseases have been recognized as a major limiting factor in backyard poultry production. Consequently, these flocks could potentially be implicated as reservoirs for poultry diseases. However, there is a considerable lack of information on disease prevalence in this production system, and the risk represented by these small flocks remains under debate. This study aimed to estimate the seroprevalence and identify related risk factors of a range of bacterial and viral pathogens of outstanding importance for the economy and public health in backyard poultry in Morocco.
Materials and Methods
A total of 712 sera samples and 258 cloacal swabs were collected from 712 backyard chickens from 15 rural markets in the Khemisset and Skhirat-Temara provinces. None of the sampled chickens received any vaccination. Sera samples were screened for antibodies against Newcastle disease virus (NDV) and low pathogenic avian influenza H9N2 subtype (LPAI H9N2) using a hemagglutination-inhibition test, against bursal infectious disease virus (IBDV) and infectious bronchitis virus (IBV) using enzyme-linked immunosorbent assay, and against Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) using a rapid serum agglutination test. Swab samples were compiled into 86 pools and submitted for molecular detection using real-time reverse-transcription–polymerase chain reaction (RT-PCR).
Results
The seroprevalences in backyard chickens for NDV, LPAI H9N2, IBDV, IBV, MG, and MS were 52.1% (371/712), 63.5% (452/712), 84.7% (603/712), 82.2% (585/712), 58% (413/712), and 74.8% (533/712), respectively. Based on the RT-PCR results, 2.3% (2/86), 62.8% (54/86), 2.3% (2/86), 63.9% (55/86), 40.7% (35/86), and 29.1% (25/86) of the pools were positive for NDV, H9N2 LPAI, IBDV, IBV, MG, and MS, respectively. Multiple coinfections (H9N2-IBV-MG), (H9N2-IBV-MS), or (IBV-MG-MS) were observed in 15.1%, 8.5%, and 8.5% of the tested samples, respectively.
Conclusion
The results show that backyard chicken flocks and rural markets have the potential to serve as reservoirs or amplifiers for poultry pathogens and could pose a risk to the commercial poultry sector. This highlights the need for a comprehensive and adapted vaccination plan for backyard chickens, and extension of efforts to increase flock owners’ awareness of avian diseases and incite the implementation of biosecurity measures at the farm level.
... Our study found that more than 35% of the respondents did not use veterinary services in the past year, and about 65% of respondents did not have a valid VCPR. Considering the current popularity of backyard poultry in the US, a lack of knowledge on disease prevention and control procedures in these biosecurity settings may increase the potential risk of zoonotic diseases infection (e.g., Salmonellosis) or the spread of avian infectious pathogens to commercial poultry farms (e.g., Avian Influenza and Newcastle Disease) [12,15,16,[29][30][31]. Therefore, proper guidance and education about disease prevention and biosecurity, simultaneous with veterinary oversight and antimicrobial stewardship, are required to promote better husbandry practices and animal health in backyard and small-scale farms, and reduce the risk of zoonotic and infectious disease spillover among conventional and backyard farm settings. ...
The number and popularity of backyard poultry and livestock farming have rapidly increased in California as well as other states in the United States following consumers’ preference for local and organic products in the last few years. This study aimed to investigate current on-farm management and farmers’ understanding of Veterinary Feed Directive (VFD) and California Senate Bill (SB) 27 implications for disease prevention, biosecurity procedures, and antimicrobial use in small-scale and backyard farms in California. The survey consisted of 38 questions. The responses of 242 backyard and small-scale livestock owners were investigated in this study. Descriptive statistics summarized survey responses, and multivariable logistic regression evaluated the association of antibiotics purchase and use, and the impact of VFD and SB27 on antibiotic use with demographics and on-farm management. Backyard and small-scale farmers in California mostly raised chickens or small ruminants with small herd sizes kept for personal use. Antibiotics were generally used for individual treatment of a sick animal with the guidance of a veterinarian. VFD and SB27 implementation promoted the judicious use of antibiotics, specifically, by enhancing the relationship between backyard and small-scale farmers with veterinarians and treating fewer animals with antibiotics under veterinary oversight. Therefore, better access to veterinary service in backyard and small-scale farms will improve the farmer’s knowledge of good husbandry practices with judicious antimicrobial use in livestock and finally contribute to reducing the risk of antimicrobial resistance in California.
... Proper implementation of biosecurity measures should be able to reduce the incidence of infection in laying hen farms, as already observed in broilers [82]. In particular, the use of dedicated boots, clothing and equipment and handwashing before and after contact with the flock should be adopted [83][84][85]. The boot baths at the entrance to the shed may be effective if the disinfectant is changed regularly every week [86]. ...
Campylobacter (C.) jejuni and C. coli are responsible for food poisoning in humans. Laying hens may host the bacteria usually without developing symptoms. The aims of this paper were to evaluate the incidence of C. jejuni and C. coli infection in laying hen flocks housed in different rearing systems, the plasma levels of two welfare indicators (corticosterone and interleukin 6, IL-6) and the antimicrobial resistance of the detected Campylobacter strains. Two different flocks (1 and 2) from cage (A), barn (B) and aviary (C) farms were investigated. The highest (p < 0.05) levels of IL-6 were detected in laying hens housed in aviaries. A similar trend emerged in corticosterone level, although differences were found between C1 and C2. C. jejuni and C. coli were identified in 43.5% and 38.9% of birds, respectively. In total, 14 out of 177 (7.9%) hens simultaneously hosted C. jejuni and C. coli. C. jejuni was prevalently detected in hens housed in barns (B1: 53.3%; B2: 46.7%) and aviaries (C1: 34.6%; C2: 86.7%). Conversely, laying hens housed in cages were significantly exposed to infection of C. coli (A1: 41.9%; A2: 80%) while, regarding barns and aviaries, a significant prevalence emerged only in flocks B2 (40%) and C1 (54.8%). Simultaneous infection was statistically significant in barn B1 (36.7%). Antibiotic resistance was mainly detected among C. coli strains, and it was most frequent for fluoroquinolones and tetracycline. Multidrug resistance was also found in C. jejuni (19.7%) and C. coli (17.5%) strains. Based on the results of this study, we recommend increasing biosecurity and hygienic measures to manage hen flocks.
... In addition to the public health risks, Table 4. Responses from backyard poultry owners (n = 125) when asked how comfortable would they be sharing anonymised data with animal health stakeholders and with whom would they be comfortable sharing the anonymised data. backyard poultry flocks have also been implicated in numerous disease outbreaks that could have serious consequences for the commercial poultry industry, including Newcastle disease (Munir et al. 2012) and highly pathogenic avian influenza (Derksen et al. 2018;Souvestre et al. 2019). ...
Aims
To assess the current level of engagement between backyard poultry keepers and veterinarians in New Zealand; to understand the opportunities and barriers for improving access to poultry health care; and to gauge the interest of backyard poultry keepers in participating in a voluntary national poultry health information system.
Materials and methods
Backyard poultry were defined as any bird species kept for non-commercial purposes. Separate cross-sectional surveys were administered to backyard poultry keepers and veterinarians in New Zealand over 12-week periods starting 22 March 2021 and 03 May 2021 respectively. The veterinarian survey was advertised in the monthly update e-mail from the Veterinary Council of New Zealand, while the survey for backyard poultry keepers was advertised on various online platforms that focus on raising backyard poultry. Results for quantitative variables were reported as basic descriptive statistics, while qualitative free-text responses from open-ended questions were explored using thematic analysis.
Results
A total of 125 backyard poultry keepers and 35 veterinarians completed the survey. Almost half (56/125; 44.8%) of backyard poultry keepers reported that they had never taken their birds to a veterinarian, with common reasons being difficulty finding a veterinarian, cost of treatment, and perceptions that most visits result in the bird being euthanised. The majority (113/125; 90.4%) of backyard poultry keepers reported that a general internet search was their primary source for poultry health advice. However, it remains unclear if owners were satisfied with the advice found online, as many cited that having access to reliable health information would be an incentive for registering with a poultry health information system. Of the veterinarian responses, 29/35 (82.9%) reported treating an increasing number of poultry in the last 5 years, although many (27/35; 77.1%) suggested they would be hesitant to increase their poultry caseload due to concerns over their lack of knowledge and confidence in poultry medicine; a lack of clinic resources to treat poultry; concerns over the cost-effectiveness of treatments; and a general feeling of helplessness when treating poultry, with most consultations being for end-stage disease and euthanasia.
Conclusion
The results of this study highlight opportunities for increased engagement between backyard poultry keepers and veterinarians, including making available accurate poultry health information and providing veterinarians with improved training in poultry medicine. The results also support the development of a poultry health information system in New Zealand to further enhance health and welfare in backyard poultry populations.
... Furthermore, carriers of NDV, village poultry population dynamics, other poultry species, wild birds, as well as temperature, humidity, the suspending agent, and exposure to light, have also been established as risk factors for maintaining NDV in the environment. . Biosafety and biosecurity measures are also improperly implemented at poultry farms, which contributes to disease outbreaks (Derksen et al., 2018;Abdelaziz et al., 2019;Sahoo et al., 2022;Ravishankar et al., 2022). ...
The continuous emergence of Newcastle disease virus (NDV) poses a persistent threat to the poultry industry. Recent increasing outbreaks of NDV in the North East region of India have highlighted the need to closely monitor and analyze the potential risk factors for Newcastle disease (ND) outbreaks. In the present study, an attempt was made to genotype the circulating Newcastle disease virus (NDV) in the backyard and commercial poultry flocks in Assam, India. Sera samples from unvaccinated backyard poultry flocks and tissue samples of ND suspected cases were collected and tested for the presence of NDV antibodies using the Haemagglutination inhibition (HI) test. A total of seven NDV isolates were analyzed from different districts of Assam, India, both genotypically and pathotypically. All isolates were characterized as virulent, carrying 112RRKQRF117 amino acid residues at the cleavage site. As determined by phylogenetic analysis, the isolates clustered with members of genotype XIII of class II NDV. Further analysis of risk factors of ND occurrence was conducted through a questionnaire survey. All the results indicated an occurrence of genotype XIII of NDV in the farms with inadequate biosecurity and farming practices.
... The presence of MS or MG strains in Italy have already been described in commercial poultry farms [21,22], despite that good biosecurity practices (single-age, all-in all-out farms) should keep these farms free of mycoplasma infection. The potential role of rural Animals 2022, 12, 962 7 of 9 poultry farms as reservoir or amplifier of respiratory pathogens and the potential risk for commercial chickens has been already reported [30,31]. ...
Mycoplasmas are recognized as avian pathogens, which may cause both respiratory disease and synovial infections in poultry, resulting in severe economic losses. Our study aims to determine the occurrence of Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) among commercial and rural laying hens located in Ragusa province (South Italy), using a duplex real time PCR. Four hundred tracheal swabs were collected from seven commercial (200 swabs) and 25 rural (200 swabs) farms without any clinical disease history. Out of 400 swabs collected, 50 (12.5%) and 93 (23.25%) were positive for MG and MS, respectively. In particular, 9 (18%) and 22 (23.65%) positive swabs for MG and MS, respectively, originated from commercial farms, compared to 41 (82%) and 71 (76.34%) obtained from rural farms. Data obtained show a lower prevalence of MG than MS in the studied farms. Moreover, both pathogens were spread in rural and commercial farms. PCR could be concluded as a rapid and sensitive method for the identification of MG and MS in areas where commercial farms that are declared Mycoplasma-free and rural flocks coexist. These data highlight the importance of surveillance also in rural poultry to monitoring the occurrence of mycoplasmas strains in strategic productive districts.
... Moreover, it may present as a mixed infection with other avian pathogens such as Mycoplasma gallisepticum (MG), avian reovirus (ARV), Escherichia coli (E. coli), and infectious bronchitis virus (IBV), thereby causing more severe diseases (Huang et al., 2015;Derksen et al., 2018;Abdelaziz et al., 2019). Since it was first reported in America in the 1950s, MS has been one of the main pathogens in commercial poultry worldwide and has led to severe economic losses (Sun et al., 2017). ...
Mycoplasma synoviae (MS) is an important avian pathogen that has brought substantial economic losses to the global poultry industry. Fast and accurate diagnosis is one of the critical factors for the control of MS infection. This study established a simple, rapid and visual detection method for MS using a recombinase-aided amplification (RAA) combined with a lateral flow dipstick (LFD). The reaction temperature and time of the RAA-LFD assay were optimized after selecting the primers and probe, and the specificity and sensitivity rates were analyzed. The results showed that RAA could amplify the target gene in 20 min at a constant temperature of 38°C, and the amplification products could be visualized by LFD within 5 min. There was no cross-reaction with Mycoplasma gallisepticum (MG), Pasteurella multocida (P.multocida), Escherichia coli (E.coli), Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), infectious bronchitis virus (IBV), and avian reovirus (ARV). Furthermore, the RAA-LFD assay exhibited high sensitivity with a detection limit of 10 copies/μL. A total of 128 clinical samples with suspected infection of MS were tested by RAA-LFD, PCR and real-time fluorescence quantitative PCR (RFQ-PCR). The coincidence rate of the detection results was 95.3% between RAA-LFD and PCR, and 98.4% between RAA-LFD and RFQ-PCR. These results suggested that the RAA-LFD method established in the present study was easy to use and was associated with stong specificity and high sensitivity. This method was very suitable for the rapid detection of MS in clinical practice.
... The zoonotic potential of poultry is constantly underestimated by private chicken owners (18). A study in Pennsylvania about awareness of zoonotic diseases revealed important gaps in animal disease knowledge, biosecurity, and public health practices by private flock owners (19). ...
Early recognition and prevention of infectious diseases in poultry flocks are essential to reduce spread from bird to bird, to prevent zoonoses, and to keep losses low. Backyard flock owners often have little knowledge about poultry health, and specialized veterinarians are difficult to find. Alternative sources for support, education, and training for noncommercial poultry are the websites of cooperative extension services offering online webinars, presentations, and programs about poultry health and diseases. The aim of this investigation was to survey 23 websites of the extension services of the top 13 states in poultry production for information on backyard poultry health. The eXtension website by the United States Cooperative Extension System was added as a nation-wide source of information. Structure, content, and presentation form were compared and analyzed. The results displayed large differences between the investigated webpages and identified opportunities for improving the sites, especially in completeness, accessibility, and presentation of the information. From 23 extension websites, 13 provided none to very limited online information and 5 websites covered almost all of the investigated content. The primary media used were articles with pictures, and only three universities added videos and webinars. Based on these results and according to the increased need for online sources about poultry health, the extension websites should provide complete and correct information or at least links to approved sources. Videos, podcasts, and webinars can increase outreach and learning achievement. This survey may help to improve the presentation and content of poultry health-related extension websites.
... The zoonotic potential of poultry is constantly underestimated by private chicken owners (18). A study in Pennsylvania about awareness of zoonotic diseases revealed important gaps in animal disease knowledge, biosecurity, and public health practices by private flock owners (19). ...
... In this study, two variables were found to be significantly associated with positivity to S. enterica in BPS: exchanging embryonated eggs and the presence of debeaked chickens, both increasing the risk of positivity to this pathogen. This situation could be explained because these two variables are a reflection of the potential relationship between BPS and commercial flocks [80]. Debeaking is a common and recommended practice in intensive systems to avoid behaviors such as cannibalism and pecking during the production process [81], consequently it is a common practice in large-scale production systems. ...
In the Metropolitana region of Chile there are 3836 backyard production systems (BPS), characterized as small-scale systems. They act as a source of zoonotic pathogens, such as Salmonella enterica and Shiga toxin-producing Escherichia coli (STEC), whose prevalence in BPS has not been fully described. The objective of this study was to determine the positivity for both agents in BPS and to establish the risk factors related to their presence. In each BPS, an epidemiological survey was undertaken, and stool samples were collected to detect these pathogens via bacteriological culture and conventional PCR techniques. Subsequently, multivariable logistic regression models were applied to establish the risk factors associated with their presence. BPS positivity rates of 11.76% for STEC and 4.7% for S. enterica were observed. The systems showed poor welfare standards and a lack of biosecurity measures. The risk factor analysis concluded that the Gini–Simpson index (p = 0.030; OR = 1.717) and the presence of neighboring intensive poultry or swine production systems (p = 0.019; OR = 20.645) act as factors that increased the risk of positivity with respect to STEC. In the case of S. enterica, exchanging embryonated eggs (p = 0.021; OR = 39) and the presence of debeaked chickens (p = 0.001; OR = 156) were determined as factors that increased the risk of positivity for this agent. For positivity with respect to both pathogens, the Gini–Simpson index (p = 0.030; OR = 1.544) and being INDAP/PRODESAL users (p = 0.023; OR = 15.026) were determined as factors that increased the risk, whereas the type of confinement (p = 0.002; OR = 0.019) decreased it. Epidemiological surveillance of these neglected populations is lacking, highlighting the fact that STEC and S. enterica maintenance on BPS represents a potential threat to public health.
... The farms were very close to each other as indicated by the presence of as many as 422 farms in 20 villages. Such small-scale commercial farms with poor biosecurity are very prone to respiratory infections(Derksen et al., 2018).Proper diagnosis of respiratory diseases appeared to be very challenging. Except for a few cases of full-blown HPAI, ND and acute ILT, the clinical signs and even necropsy findings did not lead to a definite diagnosis of a specific respiratory disease. ...
Poultry production in Bangladesh has been experiencing H5N1 highly pathogenic avian influenza (HPAI) and H9N2 low pathogenic avian influenza (LPAI) for the last 14 years. Vaccination of chickens against H5 HPAI is in practice since the end of 2012. Subsequently, the official reporting of HPAI outbreaks gradually decreased. However, the true extent of circulation of avian influenza virus (AIV) in commercial poultry production is not clear. To explore this, we conducted active surveillance in 422 small-scale commercial layer farms in 20 villages of Mymensingh and Tangail districts of Bangladesh during 2017 and 2018 for the presence of diseases with respiratory signs. A total of 88 farms with respiratory disease problems were identified and investigated during the surveillance. In addition, 22 small-scale commercial layer farms in the neighbouring areas with respiratory disease problem were also investigated on request from the farmers. Pooled samples of oropharyngeal swabs from live birds or respiratory tissues from dead birds of the farm suffering from respiratory disease problem were tested for molecular detection of avian influenza virus (AIV), Newcastle disease virus (NDV), infectious bronchitis virus (IBV), infectious laryngotracheitis virus (ILTV), Mycoplasma gallisepticum and Avibacterium paragallinarum. A total of 110 farms (88 in the surveillance site and 22 in the neighbouring region) were investigated, and one or more respiratory pathogens were detected from 89 farms. AIV was detected in 57 farms often concurrently with other pathogens. Among these 57 farms, H5, H9, both H5 and H9 or non-H5 and non-H9 AIV were detected in 28, 9, 13 or 7 farms, respectively. Birds of most of the H5 AIV-positive farms did not present typical clinical signs or high mortality. Twenty such farms were observed longitudinally, which had only 1.05%–5.50% mortality but a marked drop in egg production. This widespread circulation of H5 AIV along with H9 AIV and other pathogens in small-scale commercial layer farms, often with low mortality, reaffirms the enzootic circulation of AIV in Bangladesh, which may escape syndromic surveillance focused on unusual mortality only. To reduce public health risks, strengthening of the control programme with comprehensive vaccination, enhanced biosecurity, improved surveillance and outbreak response is suggested.
... 7,8 In addition to the commercial poultry flocks, the disease has been reported from the backyard poultry. [9][10][11][12][13] Avian mycoplasmosis was first described in turkeys in 1926 and in chickens in 1936. 4 It is caused by the organisms belonging to genus Mycoplasma, class Mollicutes (bacteria that lack cell wall) and order Mycoplasmatales. ...
Avian mycoplasmosis mainly caused by Mycoplasma gallisepticum and M. synoviae is an economically important disease of poultry industry. It causes huge economic losses in terms of decrease in weight gain, feed conversion efficiency, egg production, hatchability; increase in embryo mortality, carcass condemnation, prophylaxis and treatment cost in broiler, layer and breeder flocks. The disease is caused by four major pathogenic mycoplasmas viz., M. gallisepticum (MG), M. synoviae (MS), M. meleagradis (MM) and M. iowae (MI). The MG and MS are World Organization for Animal Health listed respiratory pathogens. MG causes chronic respiratory disease in chicken and infectious sinusitis in turkey; however, MS causes synovitis and airsacculitis in birds. The infection is transmitted both horizontally and vertically. Prevention and control measures of avian mycoplasmosis mainly comprises of biosecurity, treatment and vaccination. For vaccination of birds, inactivated bacterins, live attenuated and/or recombinant live poxvirus vaccines are commercially available against MG and MS infection. The present systematic review summarizes the different epidemiological studies carried out on MG and MS infection in poultry in different geographical locations of India and abroad over the last decade (2010–2020), economic impact, diagnosis and prevention and control.
... This hypothesis is supported by the circulation of strains belonging to the same genogroup II, both in commercial broiler flocks and in backyard chickens. The potential role of backyard chickens as a reservoir of avian pathogens for intensive breeding has been repeatedly emphasized, especially when they are located in densely poultry-populated areas [59][60][61][62]. In our study, CIAV field strains have also been detected in pullet broiler breeders, indicating that the circulation of this virus is also possible when vaccination and high biosecurity measures are in place. ...
Chicken infectious anemia virus (CIAV) is a pathogen of chickens associated with immunosuppression and with a disease named chicken infectious anemia. The present survey reports an epidemiological study on CIAV distribution in Italian broiler, broiler breeder and backyard chicken flocks. Twenty-five strains were detected by a specifically developed nested PCR protocol, and molecularly characterized by partial VP1 gene or complete genome sequencing. Viral DNA amplification was successfully obtained from non-invasive samples such as feathers and environmental dust. Sequence and phylogenetic analysis showed the circulation of field or potentially vaccine-derived strains with heterogeneous sequences clustered into genogroups II, IIIa, and IIIb. Marker genome positions, reported to be correlated with CIAV virulence, were evaluated in field strains. In conclusion, this is the first survey focused on the molecular characteristics of Italian CIAVs, which have proved to be highly heterogeneous, implementing at the same time a distribution map of field viruses worldwide.
... Zoonotic avian diseases such as salmonellosis are a risk for small flock owners, either by direct contact with backyard poultry flocks or by consumption of contaminated meat or eggs [10,11]. Low biosecurity in backyard flocks may also be an issue for commercial poultry flocks as backyard flocks can become a reservoir for pathogens [12]. This is especially relevant in a state like Alabama, which ranks second in broiler production in the United States [13]. ...
Keeping chickens as backyard pets has become increasingly popular in the United States in recent years. However, biosecurity is generally low in backyard flocks. As a consequence, they can serve as reservoirs for various pathogens that pose a risk for commercial poultry or human health. Eighty-four fecal samples, 82 from chickens and two from turkeys, from 64 backyard flocks throughout the state of Alabama were collected in the summers of 2017 and 2018. Coccidia oocysts were seen in 64.1% of flocks with oocyst counts in most samples below 10,000 oocysts per gram. Eggs of Ascaridia spp. or Heterakis gallinarum were observed in 20.3% of the flocks, and eggs of Capillaria spp. in 26.6% of the flocks. Egg counts were low, rarely exceeding 1000 eggs per gram. DNA extracted directly from fecal samples was investigated by PCR for other relevant parasites. The results showed that 4.7% of flocks were positive for Histomonas meleagridis, 18.8% of flocks for Tetratrichomonas gallinarum, 18.8% of flocks for Cryptosporidium spp. and 87.5% of flocks for Blastocystis spp. The results will help to provide information that can be used to design outreach programs to improve health and wellbeing of birds in backyard flocks.
... In an attempt to mitigate this risk, there are a limited number of studies that have tried to characterise the risk of disease from backyard poultry to commercial poultry producers with a focus on the local spread of endemic diseases where backyard poultry are in close contact with both commercial poultry and wild birds or waterfowl (Johnson et al., 2004;Derksen et al., 2018;Fiebig et al., 2009). Further studies have also investigated the general structure of the backyard poultry sector in terms of its size and composition, the geographical distribution of households keeping poultry, and their knowledge and management practices of disease control in order to help assess the risk backyard poultry pose to the commercial poultry industry (Jutzi, 2005). ...
The movements of backyard poultry and wild bird populations are known to pose a disease risk to the commercial poultry industry. However, it is often difficult to estimate this risk due to the lack of accurate data on the numbers, locations, and movement patterns of these populations. The main aim of this study was to evaluate the use of three different data sources when investigating disease transmission risk between poultry populations in New Zealand including (1) cross-sectional survey data looking at the movement of goods and services within the commercial poultry industry, (2) backyard poultry sales data from the online auction site TradeMe®, and (3) citizen science data from the wild bird monitoring project eBird.
The cross-sectional survey data and backyard poultry sales data were transformed into network graphs showing the connectivity of commercial and backyard poultry producers across different geographical regions. The backyard poultry network was also used to parameterise a Susceptible-Infectious (SI) simulation model to explore the behaviour of potential disease outbreaks. The citizen science data was used to create an additional map showing the spatial distribution of wild bird observations across New Zealand. To explore the potential for diseases to spread between each population, maps were combined into bivariate choropleth maps showing the overlap between movements within the commercial poultry industry, backyard poultry trades and, wild bird observations.
Network analysis revealed that the commercial poultry network was highly connected with geographical clustering around the urban centres of Auckland, New Plymouth and Christchurch. The backyard poultry network was also a highly active trade network and displayed similar geographic clustering to the commercial network. In the disease simulation models, the high connectivity resulted in all suburbs becoming infected in 96.4% of the SI simulations. Analysis of the eBird data included reports of over 80 species; the majority of which were identified as coastal seabirds or wading birds that showed little overlap with either backyard or commercial poultry.
Overall, our study findings highlight how the spatial patterns of trading activity within the commercial poultry industry, alongside the movement of backyard poultry and wild birds, have the potential to contribute significantly to the spread of diseases between these populations. However, it is clear that in order to fully understand this risk landscape, further data integration is needed; including the use of additional datasets that have further information on critical variables such as environmental factors.
... The presence of the MS and MG sequences showing high nucleotide similarity with corresponding sequences from Italian or foreign Mycoplasma strains is not surprising considering the features of the farms tested, which commonly introduce animals from Italian farms and from European or extra-European countries, and participate in Italian or foreign exhibitions. Haesendonck et al. (2014) and Derksen et al. (2018) reported that the backyard poultry flocks could act as reservoir or amplifier for poultry respiratory diseases serving as a continuous source of infection for industrial chickens. The present study detected the circulation of MS and MG in backyard poultry farms, confirming the potential role of this type of breeding to spread pathogens to commercial poultry production, especially in densely poultry-populated areas where backyard and commercial farms are close. ...
Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) represent the most important avian Mycoplasma species in the poultry industry, causing considerable economic losses. In Italy, the presence of MG or MS has been investigated especially in commercial poultry farms. To our knowledge, no systematic investigations on MG or MS presence using highly specific diagnostic assays have been performed in backyard poultry. The aim of this study was to detect and molecularly characterize MG and MS strains in 11 backyard poultry flocks located in different regions of Italy. Tracheal swabs were collected and DNA was extracted. For MS, a PCR targeting a vlhA gene fragment was performed, and typing and subtyping was attempted. The presence of MG was investigated by a screening PCR, then MG typing by gene-targeted sequencing (GTS). All the amplicons were sequenced, then MG and MS dendrograms were constructed. All the flocks examined resulted Mycoplasma positive: 5 out of 11 (45.45%) were MG and MS positive, 3 (27.27%) were MG positive, and the remaining 3 (27.27%) were MS positive. The MS detections were assigned to types C, D, and F. All strains of type D belonged to subtype D1 and 2 unknown subtypes were identified. A MS sequence showed peculiar characteristics, which did not allow assignment to a known MS type or subtype. MG GTS analysis identified 6 MG strains belonging to 5 subclusters circulating in Italian backyards chicken flocks. The results of this study provide evidence of a risk for commercial poultry farms, especially in areas where backyard and commercial farms are close, suggesting the implementation of biosecurity measures.
... Typically, acute or chronic infectious synovitis, air sacculitis synovitis, and eggshell apex abnormality develop following MS infection which result in reduced egg production (Zhu et al., 2017;Kursa et al., 2019). In addition, MS infection can produce subclinical symptoms and lead to co-infection with Mycoplasma gallisepticum (MG), Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and other avian pathogens (Sun et al., 2017;Ball et al., 2018;Derksen et al., 2018). Currently, control treatments for MS include the use of vaccines and antibiotics, and doxycycline, oxytetracycline, tylvalosin, tylosin, and pleuromutilins are sensitive antimicrobial agents for MS; however long-term drug use can lead to drug resistance (Kreizinger et al., 2017). ...
In this study, a rapid, specific, and sensitive detection assay for Mycoplasma synoviae (MS) was established using a polymerase spiral reaction (PSR) method. A pair of primers were designed according to the conserved region of the vlhA gene of MS, and PSR results were assessed using agarose gel electrophoresis and color rendering with a dye indicator. The optimum reaction temperature and time for PSR using the specific primers were 62°C and 40 min in a water bath, respectively. The sensitivity of the PSR assay for MS detection was 100 times more than that of the polymerase chain reaction assay based on agarose gel electrophoresis results and color change detected by the naked eye. Further experiments demonstrated that the primers specifically detected MS and showed no cross-reaction with other prevalent avian pathogens. Clinical sample testing confirmed that the MS-PSR assay is simple, rapid, specific, and sensitive, and thereby very suitable for application and promotion in the field and laboratories of grassroots units.
Introduction. The intestinal microbiocenosis is the most complex and important biotope of the body formed in the process of individual development. Material and methods. The study was conducted on groups of 20-25-day-old chicks. The first group was housed under standard vivarium conditions with artificially maintained optimal climatic parameters. The second group was raised in a rural homestead in the Kyiv region, on pasture with access to water, and fed twice daily with a blend of grains supplemented with kitchen wastes. Samples of chicken droppings (10 per group) were analyzed according to current international ISO standards using certified nutrient media and equipment. Results. Escherichia coli, Klebsiellas spp., Enterococcus spp. were isolated from 100% of samples from chickens kept in simulated conditions of an industrial poultry house, and Pseudomonas aeruginosa was isolated from 70% of samples. Escherichia coli and Enterococcus spp. were isolated from free-range chickens in 100% of cases. The analysis revealed that in pasture-raised chickens, Klebsiella spp. and Pseudomonas aeruginosa were absent from the litter, with significantly higher levels of normal microflora (Enterococcus spp.). Conclusions. Backyard-raised chickens showed no pathogenic zoonotic bacteria, in contrast to those raised under controlled conditions with optimal climate and standard diets. Висновки. Виявлено відмінності у складі індикаторних бактерій курячого посліду за різних умов утримання. Встановлено відсутність патогенних зоонозних бактерій у курей в умовах подвірного утримання, на відміну від курей, які утримувалися в умовах штучного забезпечення оптимальних кліматичних умов на стандартному раціоні.
Infectious laryngotracheitis (ILT) is a very serious worldwide respiratory disease of poultry, with many countries reporting ILT infections over the last decade. However, few reports are available regarding ILT disease prevalence in poultry in Turkey. Accordingly, the present study investigated ILT infection in Turkish broiler flocks between 2018 and 2022. Circulating ILT strains were characterized by sequence and phylogenetic analysis of two fragments of the infected-cell protein 4 gene. ILT virus (ILTV) was confirmed by quantitative PCR in 8 of the 21 flocks examined. As in other diseases, co-infections with other respiratory pathogens in confirmed ILT cases may worsen the symptoms and prolong the disease course. The present study confirmed co-infections with infectious bronchitis virus (13/21 tested flocks and 5/8 ILTV-positive flocks), indicating the importance of these pathogens in the occurrence of ILT infections.
This study aimed to examine the depletion of tilmicosin residues in Gushi chickens following the administration at a concentration of 75 mg/L in their drinking water for three consecutive days. Plasma, liver, kidney, lung, muscle, and skin + fat samples were collected from 6 chickens at 6 h, 1, 3, 5, and 7 days after the treatment. Tilmicosin concentrations in the samples were determined using a high‐performance liquid chromatography (HPLC) method. The findings revealed that the highest tilmicosin residues were detected in the liver, followed by the kidney, lung, skin + fat, muscle, and plasma. Notably, at 7 days post‐treatment, no drug residue was detected in all samples except for the liver and kidney. The non‐compartmental model was employed to calculate relevant pharmacokinetic parameters. The elimination half‐lives ( t 1/2λz ) of tilmicosin were as follows, ranked from long to short: skin + fat (45.42 h), liver (44.17 h), kidney (40.06 h), plasma (37.64 h), lung (31.39 h), and muscle (30.05 h). Considering the current residue depletion and the maximum residue limits (MRLs) set by Chinese regulatory authorities, the withdrawal times for tilmicosin were estimated as 18.91, 10.81, and 8.58 days in the kidney, liver, and skin + fat, respectively. A rounded‐up value of 19 days was selected as the conclusive withdrawal time. Furthermore, based on the observed tilmicosin concentrations in plasma and lung, combined with previously reported minimum inhibitory concentration (MIC) values against Mycoplasma gallisepticum , the current dosing regimen was deemed adequate for treating Mycoplasma gallisepticum infections in Gushi chickens.
This study aimed to detect possible viral agents in backyard poultry where numerous commercial poultry companies are located. The backyard flock had non-vaccinated 30 meat-type chickens and four turkey pullets. Serum samples and tracheal swabs were taken from chickens and turkey pullets showing respiratory signs. Serum antibody levels were measured using commercial ELISA kits against Avian Influenza Virus (AIV), Newcastle Disease Virus (NDV), Infectious Bronchitis Virus (IBV), Avian Metapneumovirus (AMPV), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), and Ornithobacterium rhinotracheale (ORT). In addition, tracheal swabs were tested for AIV serotypes H5, H7, and H9, NDV, IBV, AMPV, MG, MS, Pasteurella multocida, Avibacterium paragallinarum, and Bordetella avium by circular amplification technology (CAT). Anti-MS, -IBV, -MG, -NDV, -AMPV, and -ORT IgG antibodies were detected in some chicken sera, while anti-NDV, -MG, -MS, and -ORT IgG antibodies were detected in turkey sera. All avian tracheal swabs were positive for MG; however, IBV was only detected from chicken tracheal samples by CAT. The IBV strains were genotyped by sequencing a part of the S1 glycoprotein gene. Two isolates showed 99.35% and 98.69% nucleotide and 99.02% amino acid similarities with the 4/91 IBV strain. Two strains showed 99.35% nucleotide and 100% amino acid sequence identity to each other. Turkeys and chickens in the flock had MG and MG/IBV co-infections, respectively. Consequently, the presence of mutants of 4/91 IBV genotypes and MG found in backyard poultry could be a potential epidemiological source for commercial flocks in poultry integrations.
Infectious laryngotracheitis (ILT) is a disease of high economic consequence to the poultry sector. Gallid herpesvirus 1 (GaHV-1), a.k.a infectious laryngotracheitis virus (ILTV), under the genus Iltovirus, and the family Herpesviridae, is the agent responsible for the disease. Despite the clinical signs on the eld suggestive of ILT, it has long been considered nonexistent and a disease of no concern in Ethiopia. A cross-sectional study was conducted from November 2020 to June 2021 in three selected zones of the Amhara region (Central Gondar, South Gondar, and West Gojjam zones), Ethiopia, with the objective of estimating the seroprevalence of ILTV in chickens and identifying and quantifying associated risk factors. A total of 768 serum samples were collected using multistage cluster sampling and assayed for anti-ILTV antibodies using indirect ELISA. A questionnaire survey was used to identify the potential risk factors. Of the 768 samples, 454 (59.1%, 95% CI: 0.56-0.63) tested positive for anti-ILTV antibodies. Mixed-e ect logistic regression analysis of potential risk factors showed that local breeds of chicken were less likely to be seropositive than exotic breeds (OR: 0.38, 95% CI: 0.24-0.61). In addition, factors such as using local feed source (OR: 6.53, 95% CI: 1.77-24.04), rearing chickens extensively (OR: 1.97, 95% CI: 0.78-5.02), mixing of di erent batches of chicken (OR: 14.51, 95% CI: 3.35-62.77), careless disposal of litter (OR: 1.62, 95% CI: 0.49-4.37), lack of house disinfection (OR: 11.05, 95% CI: 4.09-47.95), lack of farm protective footwear and clothing (OR: 20.85, 95% CI: 5.40-80.45), and careless disposal of dead chicken bodies had all been associated with increased seropositivity to ILTV. erefore, implementation of biosecurity measures is highly recommended to control and prevent the spread of ILTV. Furthermore, molecular con rmation and characterization of the virus from ILT suggestive cases should be considered to justify the use of ILT vaccines.
The term gamebird describes any species of bird that may be used for hunting, including upland gamebirds, waterfowl, and woodland birds. An important program which includes biosecurity in these groups of birds is the National Poultry Improvement Plan. Large commercial gamebird operations usually have one or two gamebird breeds on their farms but, as the name implies, have thousands of birds on their premises. The gamebird industry is made up of breeding operations, hatcheries, brooding, rearing to release, and hunting preserves. Many people raise small numbers of gamebird species as a hobby or to release on their own property. These hobby growers frequently have other species of birds such as fancy chickens, waterfowl and turkeys. Noncommercial poultry raising has numerous challenges in terms of biosecurity. However, there are numerous simple strategies that can be taken to reduce disease risks. This chapter details some of these strategies.
Backyard chickens are increasingly popular, and their husbandry varies widely.How backyard chickens are housed may influence the accessibility of chicken feed and water to wild birds, and thus, the contact rates between both groups. Increased contacts have implications for pathogen transmission; for instance, Newcastle disease virus (NDV) or avian influenza virus (AIV) may be transmitted to and from backyard chickens from contaminated water or feed. Given this potentially increased pathogen risk to wild birds and backyard chickens, we examined which wild bird species are likely to encounter backyard chickens and their resources.We performed a supplemental feeding experiment followed by observations at three sites associated with backyard chickens in North Georgia, USA. At each site, we identified the species of wild birds that:a) shared habitat with the chickens, b) had a higher frequency of detection relative to other species, and c) encountered the coops.We identified 14 wild bird species that entered the coops to consume supplemental feed and were considered high-risk for pathogen transmission. Our results provide evidence that contact between wild birds and backyard chickens is frequent and more common than previously believed,which has crucial epidemiological implications for wildlife managers and backyard chicken owners.
This study is part of a 2 year disease surveillance project conducted to establish the prevalence of poultry and zoonotic pathogens, including Campylobacter spp., among small poultry flocks in Ontario, Canada. For each post-mortem submission to the Animal Health Laboratory, a pooled sample of cecal tissue was cultured for Campylobacter spp., and a husbandry and biosecurity questionnaire was completed by the flock owner (n = 153). Using both laboratory and questionnaire data, our objective was to investigate demographic, husbandry, and biosecurity factors associated with the presence of Campylobacter spp. in small flocks. Two multivariable logistic regression models were built. In the farm model, the odds of Campylobacter spp. were higher in turkeys, and when birds were housed in a mixed group with different species and/or types of birds. The odds were lower when antibiotics were used within the last 12 months, and when birds had at least some free-range access. The effect of pest control depended on the number of birds at risk. In the coop model, the odds of Campylobacter spp. were lower when owners wore dedicated clothing when entering the coop. These results can be used to limit the transmission of Campylobacter spp. from small poultry flocks to humans.
The proceedings is divided into seven parts with seventeen chapters. Part 1 discusses the alternative systems for poultry, impact of legislation and assurance schemes on alternative systems for poultry welfare and the politics and economics; while Part 2 deals with the effects of alternative systems on disease and health of poultry, production systems for laying hens and broilers and risk of human pathogens. Part 3 presents the introduction to village and backyard poultry production and the technology and programmes for sustainable improvement of village poultry production. Part 4 reports on the production systems for waterfowl and game bird breeding, brooding and rearing. The Part 5 discusses the housing and management of layer breeders in rearing and production, furnished cages for laying hens and the performance, welfare, health and hygiene of laying hens in non-cage systems in comparison with cage systems. On the other hand, the housing and management, and alternative systems for meat chickens and turkeys are highlighted in Part 6, while the challenges and opportunities for alternative production systems are elaborated in Part 7.
As backyard poultry (BYP) ownership has increased in the US, the demand for veterinarians who treat BYP has also increased. However, veterinarians who treat BYP remain scarce and are mostly small animal veterinarians and exotic animal practitioners who have limited training in food animal regulatory practices. To gauge whether veterinary students are interested in learning more about BYP and what BYP topics to include in an online training program for veterinary students, a BYP knowledge assessment was conducted. Pre-clinical veterinary students were asked to self-rate their level of knowledge on various topics for both small animal practice and BYP using Likert-type ordinal scales. Wilcoxon signed-rank tests of those Likert data showed significant differences ( p < .01 at α = .05) between self-assessed knowledge of poultry and small animal medicine for all surveyed topics. Specifically, veterinary students ranked themselves as less knowledgeable on poultry concepts than on small animal medicine concepts. Nevertheless, students expressed interest in an online training program for treating BYP and drug residue avoidance in BYP, despite having chosen future career tracks that are not exclusively poultry. Specific topics students expressed interest in with respect to BYP training included anatomy, husbandry, prescribing medications, treatment options, food safety, antimicrobial resistance, and extra-label drug use.
Biosecurity is an important part of any avian health management program. Informational resources are readily available for both poultry owners and veterinarians from a variety of sources. Clear advantages of practicing biosecurity include having healthy bird; minimizing the potential for significant costs and loss of revenue; protecting human health; protecting future ability to move birds without restriction; protecting other allied industries such as feed suppliers; and protecting export markets. The following procedures can be used to reduce interactions between poultry and infectious agents: minimizing human contact, establishing a visitor's policy, reducing exposure from contaminated food and water, reducing exposure from pests, and reducing exposure from new poultry introductions. The following procedures can be used to minimize the introduction of poultry to areas where infectious agents are present: management of sick birds, carcass management, and vaccination.
Mycoplasma gallisepticum (MG) is an economically significant pathogen of poultry which results in severe disease especially when complicated by other respiratory pathogens. The objectives of this study, were to establish preliminary baseline data on the respiratory pathogens in MG positive commercial turkey flocks in California and to identify key predictor variables of MG serologic status. The retrospective study analyzed a total of 54 flocks in which MG was confirmed in central California from 2008 to 2019 by California Animal Health and Food Safety laboratories (CAHFS). Of the 54 flocks that were confirmed positive by quantitative polymerase chain reaction (qPCR), 34(63%) had positive MG ELISA titers and 20 (37%) were negative. Escherichia coli was the most common pathogen isolated in 13 (24.1%) flocks followed by Bordetella avium, Mycoplasma synoviae and Ornithobacterium rhinotracheale in 10 (18.5%), 8 (14.8%) and 7 (13%) respectively. The mean age at which flocks were submitted for necropsy to the CAHFS laboratories and confirmed as MG qPCR positive was approximately 15 weeks. To assess the main effects on MG serologic status, a stepwise logistic regression model was developed. Of the six independent variables examined (age of flock, season, farm size, company, number of concurrent pathogens and year), only age of flock (odds ratio [OR] = 1.7, p = 0.002) was determined to be a significant factor in the final model. This study provides preliminary baseline data on the concurrent infectious pathogens in qPCR MG positive commercial turkeys. It also identified potentially critical information as well as the age of detection, which may aid in the implementation of targeted control and prevention strategies.
Infectious bronchitis virus (IBV) causes significant losses in the poultry industry throughout the world. Here we characterize the lesions of infectious bronchitis (IB), IBV prevalence and identify the circulating strains in small flocks in California. Backyard chickens (BYCs) submitted to the Davis (Northern California; NorCal) and San Bernardino (Southern California; SoCal) branches of the California Animal Health and Food Safety Laboratory System from January through March 2019 were included in the study. Trachea, kidney, and cecal tonsils were collected for qRT-PCR, histology, immunohistochemistry (IHC) and sequence analysis. A total of 50 chickens out of 169 submissions tested positive for IBV by qRT-PCR. Of these, 16% (20/123) were from NorCal and 65% (30/46) from SoCal laboratory. The cecal tonsil was the most frequently positive tissue by qRT-PCR and IHC. Lymphoplasmacytic tracheitis was the most frequent histopathologic finding in 24 of 39 birds while the kidney showed interstitial nephritis, tubular necrosis, tubular dilation and/or gout in 14 of 43 chickens. Infectious bronchitis virus played a primary role or a synergistic effect in the mortality of chickens succumbed by other infectious diseases. The sequences of IBV detected in 22 birds were analyzed and 14 strains were most similar to CA1737. One strain each matched Conn46, Cal99, and ArkDPI, and the remaining five did not have a substantial match to any available reference strains. The findings in this study indicate that small flocks can be reservoirs of IBV and might facilitate evolution of new variants as well as reversion of attenuated strains to virulence.
In 2017, the Turlock branch of the California Animal Health & Food Safety laboratory system received a significant increase in infectious coryza (IC) necropsy cases, with a total of 54 submissions originating from commercial broilers (n = 40), commercial layers (n = 11), and backyard chickens (n = 3). Layer flocks positive for IC were distributed within the adjacent counties of Merced and Stanislaus, while broiler flocks were concentrated within Merced County. The backyard flocks were located in Alameda and Sacramento counties. The clinical and pathologic presentation was consistent with IC, although septicemic lesions were also noticed. Avibacterium paragallinarum was isolated and identified by PCR from the respiratory tract as well as from extrarespiratory sites. Polymicrobial infections involving other viral (infectious bronchitis virus, infectious bursal disease virus) and bacterial (Mycoplasma spp., Escherichia coli, Ornithobacterium rhinotracheale, Gallibacterium anatis biovar haemolytica) agents were commonly reported. Thirteen selected Av. paragallinarum isolates were successfully characterized as serovar C (Page scheme) and serovar C2 (Kume scheme). They shared a unique enterobacterial repetitive intergenic consensus (ERIC) PCR, differing from the four reference strains, and showed consistent high minimum inhibitory concentration values for tetracycline, suggesting a common origin from a single clone. Based on these results, high biosecurity standards and proper immunization of susceptible, multi-age flocks should always be implemented and adjusted as needed. The importance of backyard flocks should not be underestimated due to their unique epidemiologic role.
Although it has become increasingly popular to keep backyard chickens in the United States, few studies have provided information about these flocks. An online survey of backyard chicken owners was conducted, advertised through Master Gardeners' websites, social platforms, and other sites. The survey had 56 questions about flock history, husbandry, health care, and owner attitudes and demographics. Surveys received (n = 1,487) came almost equally from urban, suburban, and rural areas. Most (71%) respondents owned fewer than 10 chickens and had kept chickens for less than 5 yr (70%). Major reasons for keeping chickens were as food for home use (95%), gardening partners (63%), pets (57%), or a combination of these. Rural respondents had larger flocks (P ≤ 0.001) and were more likely to keep chickens as a source of income or for show (P ≤ 0.001) than urban and suburban respondents. Owners thought that eggs/meat from their chickens were more nutritious (86%), safer to consume (84%), and tasted better (95%) than store-bought products, and also that the health and welfare of their chickens was better (95%) than on commercial farms. The majority (59%) indicated no flock health problems in the last 12 mo. However, there was a lack of awareness about some poultry health conditions. Many knew either little or nothing about exotic Newcastle or Marek's disease, and most (61%) did not vaccinate against Marek's. Respondents wanted to learn more about various flock management topics, especially how to detect (64%) and treat (66%) health problems. The Internet was the main source of information (87%) used by backyard flock owners, followed by books/magazines (62%) and feed stores (40%). Minimizing predation was the most cited challenge (49%), followed by providing adequate feed at low cost (28%), dealing with soil management (25%), and complying with zoning regulations (23%). The evidence obtained from this survey will help to determine what information and resources are needed to maintain good biosecurity and improve the health and welfare of backyard flocks.
Major implications on a country's economy, food source, and public health. With recent concern over the highly pathogenic avian influenza outbreaks around the world, government agencies are carefully monitoring and inspecting live bird markets, commercial flocks, and migratory bird populations. However, there remains limited surveillance of non-commercial poultry. Therefore, a cross-sectional study was conducted in backyard poultry flocks using a convenience sampling method across three regions of Maryland from July 2011 to August 2011. The objective of this study was to develop a better understanding of the ecology and epidemiology of avian influenza by investigating the prevalence and seroprevalence in this potentially vulnerable population and by evaluating biosecurity risk factors associated with positive findings. Serum, tracheal, and cloacal swabs were randomly collected from 262 birds among 39 registered premises. Analysis indicated bird and flock seroprevalence as 4.2% (11/262) and 23.1% (9/39), respectively. Based on RT-qPCR analysis, none of the samples were found to be positive for AI RNA and evidence of AI hemagglutinin subtypes H5, H7, or H9 were not detected. Although no statistically significant biosecurity associations were identified (p≤0.05), AI seroprevalence was positively associated with exposure to waterfowl, pest control, and location. AI seropositive flocks exposed to waterfowl were 3.14 times as likely to be AI seropositive than those not exposed (p = 0.15). AI seropositive flocks that did not use pest control were 2.5 times as likely to be AI seropositive compared to those that did and AI seropositive flocks located in the Northern region of Maryland were 2.8 times as likely to be AI seropositive than those that were located elsewhere.
In January 2004, highly pathogenic avian influenza
(HPAI) virus of the H5N1 subtype was first confirmed in
poultry and humans in Thailand. Control measures, e.g.,
culling poultry flocks, restricting poultry movement, and
improving hygiene, were implemented. Poultry populations
in 1,417 villages in 60 of 76 provinces were affected in
2004. A total of 83% of infected flocks confirmed by laboratories
were backyard chickens (56%) or ducks (27%).
Outbreaks were concentrated in the Central, the southern
part of the Northern, and Eastern Regions of Thailand,
which are wetlands, water reservoirs, and dense poultry
areas. More than 62 million birds were either killed by HPAI
viruses or culled. H5N1 virus from poultry caused 17
human cases and 12 deaths in Thailand; a number of
domestic cats, captive tigers, and leopards also died of the
H5N1 virus. In 2005, the epidemic is ongoing in Thailand.
A real-time reverse transcriptase PCR (RRT-PCR) assay based on the avian influenza virus matrix gene was developed for the
rapid detection of type A influenza virus. Additionally, H5 and H7 hemagglutinin subtype-specific probe sets were developed
based on North American avian influenza virus sequences. The RRT-PCR assay utilizes a one-step RT-PCR protocol and fluorogenic
hydrolysis type probes. The matrix gene RRT-PCR assay has a detection limit of 10 fg or approximately 1,000 copies of target
RNA and can detect 0.1 50% egg infective dose of virus. The H5- and H7-specific probe sets each have a detection limit of
100 fg of target RNA or approximately 103 to 104 gene copies. The sensitivity and specificity of the real-time PCR assay were directly compared with those of the current
standard for detection of influenza virus: virus isolation (VI) in embryonated chicken eggs and hemagglutinin subtyping by
hemagglutination inhibition (HI) assay. The comparison was performed with 1,550 tracheal and cloacal swabs from various avian
species and environmental swabs obtained from live-bird markets in New York and New Jersey. Influenza virus-specific RRT-PCR
results correlated with VI results for 89% of the samples. The remaining samples were positive with only one detection method.
Overall the sensitivity and specificity of the H7- and H5-specific RRT-PCR were similar to those of VI and HI.
A questionnaire was designed in order to gather information about bedding material and footbath preparation and maintenance in different productive units across the state of California.This information was used to plan two experiments. In the first experiment, we tested the effectiveness of footbaths in inactivating highly pathogenic (HP) and low pathogenic (LP) avian influenza viruses (AIVs) on rubber boots. Surprisingly, quaternary ammonia- and quaternary ammonia + glutaraldehyde-based footbaths were not able to eliminate live HPAIV (H5N8) and LPAIV (H6N2) particles on boots, while a chlorine-based granulated disinfectant was able to destroy the virus at contact. These results demonstrated the potential of AIV, particularly the HPAIV isolate, to persist even if exposed to disinfecting footbaths, and suggest that footbaths, as a single tool, are not capable of preventing pathogen introduction into commercial flocks. In the second experiment, we investigated the persistence of HPAIV (H5N8) and LPAIV (H6N2) in bedding material and feces obtained from Turkey, broiler, and egg-layer commercial productive units. Samples were collected at different times after spiking the bedding materials and feces. Results showed that HPAIV (H5N8) was more persistent than LPAIV (H6N2) in layer feces and bedding material obtained from commercial broilers and Turkeys. Live HPAIV particles persisted 96 hr, the last time point measured, in layer feces and less than 60 hr in broiler and Turkey bedding. In contrast, LPAIV persisted less than 24 hr after being spiked in all the different substrates. Further research in biosecurity practices such as footbath preparation and maintenance and better understanding of the mechanism of the increased persistence of AIV is warranted in order to identify effective litter treatments that destroy live virus in bedding material.
Seroprevalence studies on respiratory pathogens have been done extensively in commercial laying hens, broilers, and, to a lesser extent, backyard poultry. In Europe, seroprevalence studies in backyard and fancy breed poultry flocks are scarce and limited to a few pathogens, such as Mycoplasma gallisepticum (MG); others, such as Ornithobacterium rhinotracheale (ORT), are missing. A commercial ELISA for detection of antibodies against six selected pathogens was performed on 460 serum samples from chickens across Flanders. Anti-ORT antibodies were, by far, the most prevalent, with a prevalence of 95.4%. Infectious bronchitis virus, Mycoplasma synoviae, and avian metapneumovirus antibodies were found in 75.6%, 76.3%, and 63.5% of the animals, respectively. Antibodies against MG and infectious laryngotracheitis virus were found in 36.7% and 30% of the animals, respectively. These data demonstrate the high seroprevalence of respiratory pathogens among hobby poultry; therefore, it is possible that this group could act as a reservoir for commercially kept poultry.
This study examines backyard poultry flock owners perspectives about bird health and highly pathogenic avian influenza (HPAI) in order to understand how they compare to previous reports of public responses to emerging infectious diseases and how they might influence compliance with government HPAI control activities. We conducted interviews with backyard flock owners in southwestern British Columbia, Canada because it has a high density of commercial and backyard poultry flocks and is the location of three recent HPAI outbreaks, including a large outbreak in 2004 in which 553 backyard flocks were culled. We used a qualitative open-ended interview method to build trust with interviewees and collect rich data, and latent content analysis to extract participants’ perspectives from the interview transcripts. The 18 backyard flock owners interviewed saw their poultry as very different from commercial poultry. They kept birds for emotional reasons, to provide food, and to preserve poultry genetic diversity. They stated that small flock husbandry methods, including access to the outdoors, were important for the health of their flock. They viewed HPAI as a trade concern for commercial poultry farms and distrusted government’s motivation for and technical proficiency at implementing disease control activities in backyard flocks. Participants felt that government’s role should be to keep people informed about where infected farms were located and to provide information on how to self-quarantine backyard flocks and where to report potential cases. All participants stated that before they would support culling of their flock, their birds would need to show clinical signs of disease or have a positive test for avian influenza. These perspectives were not well aligned with current Canadian HPAI control policies.
Several epidemiologic surveillance studies have implicated backyard flocks as a reservoir for poultry diseases; however, much debate still exists over the risk these small flocks pose. To evaluate this concern, the prevalence of Newcastle disease (ND), infectious laryngotracheitis (ILT), Mycoplasma gallisepticum (MG), and Salmonella was determined in 39 Maryland backyard flocks. Serum, tracheal, and cloacal swabs were randomly collected from 262 birds throughout nine counties in Maryland. Through PCR and ELISA analysis, disease prevalence and seroprevalence were determined in flocks, respectively, for the following: ND (0%, 23%); ILT (26%, 77%); MG (3%, 13%); and Salmonella (0%, not done). Vaccine status could not be accurately confirmed. Premise positives were further differentiated and identified by partial nucleotide sequencing. Screening of the 10 ILT premise positives showed that most were live attenuated vaccines: eight matched a tissue culture origin vaccine, one matched a chicken embryo origin (CEO) vaccine, and one was CEO related. The single MG-positive flock, also positive for the CEO-related sequence, was identified as the infectious S6 strain. The prevalence rates for these economically important poultry diseases ranged from none to relatively low, with the vast majority of sampled flocks presenting no clinical signs.
In recent years, outbreaks of highly pathogenic avian influenza (HPAI) viruses have caused the death of millions of poultry and of more than 200 humans worldwide. A proper understanding of the transmission dynamics and risk factors for epidemic spread of these viruses is key to devising effective control strategies. The aim of this study was to quantify the epidemiological contributions of backyard flocks using data from the H7N7 HPAI epidemic in the Netherlands in 2003. A dataset was constructed in which flocks in the affected area were classified as susceptible (S), infected but not yet infectious (E), infectious (I), and removed (R). The analyses were based on a two-type SEIR epidemic model, with the two types representing commercial poultry farms and backyard poultry flocks. The analyses were aimed at estimation of the susceptibility (g) and infectiousness (f) of backyard flocks relative to commercial farms. The results show that backyard flocks were considerably less susceptible to infection than commercial farms (g = 0.014; 95%CI = 0.0071-0.023), while estimates of the relative infectiousness of backyard flocks varied widely (0 < or = f < or =5). Our results indicate that, from an epidemiological perspective, backyard flocks played a marginal role in the outbreak of highly pathogenic avian influenza in the Netherlands in 2003.
A survey was conducted to characterize domestic and exotic bird populations, estimate seroprevalence to selected disease agents, and describe health management practices on 62 premises containing "backyard" flocks located within one mile of 22 commercial California meat-turkey flocks participating in National Animal Health Monitoring System (NAHMS). Chickens were present on 56 backyard premises and turkeys on seven. Antibodies were identified against Mycoplasma gallisepticum, M. synoviae, M. meleagridis, Salmonella pullorum, Newcastle disease virus, avian encephalomyelitis virus, Bordetella avium, hemorrhagic enteritis virus, infectious bronchitis virus, and infectious bursal disease virus in 367 blood samples from 32 backyard premises. Twenty-two owners of backyard premises said they restricted visitor contact with their birds, and two required visitors to wear rubber boots and use boot disinfectant. Owners of seven premises used biologics and/or pharmaceutics for disease prevention. One family member worked on a commercial turkey ranch, but no other contact between owners, relatives, or employees and commercial poultry was reported.
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Available from: www.aphis.usda.gov/animal_health/emergency_
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four U.S. cities. 2013. https://www.aphis.usda.gov/animal_health/nahms/
poultry/downloads/poultry10/poultry10_dr_Urban_Chicken_Four.pdf
16. USDA APHIS Veterinary Services. Highly pathogenic avian
influenza (HPAI) response ready reference guide-overview of zones. 2017.
Available from: www.aphis.usda.gov/animal_health/emergency_
management/downloads/hpai/hpai_zones.pdf
17. USDA APHIS Veterinary Services. National Poultry Improvement
Plan program standards. 2014. Available from: https://www.
poultryimprovement.org/documents/ProgramStandardsAugust2014.pdf