John A Larbi

• PhD
• Professor (Associate) at Kwame Nkrumah University of Science and Technology

Background Ticks are vectors of pathogens that affect the health of animals and humans. With the constant trade of livestock across borders, there is the risk of new tick species invasion accompanied by the spread of infectious tick‐borne pathogens. Aim This study sought to determine the diversity of tick species within abattoirs and a slaughter s...

Modified landscapes could create breeding habitats for mosquitoes and affect their community structure and susceptibility with implications for their management. Hence, in this study, household mosquito control methods in two urbanized landscapes; industrial and residential human settlements, in Ghana and insecticide susceptibility of the inhabitin...

Modifed landscapes could create breeding habitats for mosquitoes and afect their community structure and susceptibility with implications for their management. Hence, in this study, household mosquito control methods in two urbanized landscapes; industrial and residential human settlements, in Ghana and insecticide susceptibility of the inhabiting...

Tick-borne pathogens continue to infect humans and animals worldwide. By adapting to the movement of livestock, ticks facilitate the spread of these infectious pathogens. Humans in close contact with animals that could be amplifying hosts are especially at risk of being infected with tick-borne pathogens. This study involved the collection of dry b...

Maize production is an important enterprise in Ghana, providing livelihood for thousands of people. It is challenged by fall armyworm infestation causing destruction to many cultivated lands in production enclaves and threatening food security. Effective control, however, requires information on the actual pest infestation as well as the effect of...

Background The effect of hypertension is aggravated by lifestyle factors such as alcohol consumption. This study sought to determine the association between alcohol consumption and the level of blood pressures among HIV seronegative and seropositive cohorts. Methods This secondary analysis was performed on a cross-sectional survey data of 17 922 p...

Sampled ticks were screened for Crimean-Congo haemorrhagic fever virus (CCHFV) using an assay that targets the nucleoprotein gene region of the S segment, a conserved region of the CCHFV genome. Minimum infection rates of 0.34% and 0.10% were obtained when testing pools of Hyalomma rufipes and Amblyomma variegatum, respectively. Next-generation seq...

The impact of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) (initiated in 2000 in Ghana and ran for 12 years) in mitigating soil-transmitted helminth (STH) infections in LF-endemic areas is unknown. During a 1-year hiatus which ensued between 2011 and 2012, a longitudinal study was conducted to determine GPELF effect on hookworm in...

The ability of ticks to adapt to different ecological zones, coupled with the spread of infectious pathogens negatively affects livestock production and thus, there is a need for better control strategies. However, control measures within a geographical region can only be effective if there is available information on tick population dynamics and e...

Background In addition to curative treatment against the pathogenic asexual stages of malaria parasites, targeting the transmissible sexual stages is essential to impede the spread of drug resistance. The present study relies on a clinical trial testing the benefits of combining Atovaquone Proguanil (AP) with Artemether-lumefantrine (AL) in the tre...

The consumption of fruits is an important source of vitamins and micronutrients. Despite their health benefits, fruits have been linked to food-borne infections, particularly when untreated animal excreta are used in their cultivation and not properly washed before consumption. This study aimed to evaluate the parasitological, fungal, and bacteriol...

Leishmania parasites, which are spread by infected female sand flies, are the cause of the disease leishmaniasis. Although cutaneous leishmaniasis has been found to occur in the Volta Region, there is limited data on vector species and reservoirs. This study focused on the Tsatee community, in the South Dayi District of the Volta Region, and is aim...

Ticks are efficient vectors for transmitting pathogens that negatively affect livestock production and pose a risk to public health. In this study, Babesia and Theileria species were identified in ticks collected from cattle, sheep and goats from the Kassena-Nankana Districts of Ghana between February and December 2020. A total of 1550 ticks were c...

Ticks are arthropods of veterinary and medical importance which spread zoonotic patho- gens that link animal and human health. In this study, ticks were collected from 448 live- stock between February and December 2020 in the Kassena-Nankana Districts of Ghana and screened for the presence of zoonotic pathogens DNA using PCR and sequencing approach...

Background Toxoplasmosis is a zoonotic disease that is asymptomatic in many but can spread through the placenta during pregnancy causing miscarriage, stillbirth, intrauterine death, and neurologic impairments. This study reports on the proportion and risk factors associated with the seropositivity of Toxoplasma gondii among pregnant women visiting...

Ticks are a public health threat due to their tendency to spread pathogens that affect humans and animals. With reports of Rhipicephalus (Boophilus) microplus invasion in neighbouring countries, there is the risk of this species invading Ghana through livestock trade. Previous identification of tick species in Ghana has been based on morphological...

Tick-borne pathogens harm livestock production and pose a significant risk to public health. To combat these effects, it is necessary to identify the circulating pathogens to create effective control measures. This study identified Anaplasma and Ehrlichia species in ticks collected from livestock in the Kassena-Nankana Districts between February 20...

Background: Asymptomatic Plasmodium carriers form the majority of malaria-infected individuals in most endemic areas. A proportion of these asymptomatically infected individuals carry gametocytes, the transmissible stages of malaria parasites, that sustain human to mosquito transmission. Few studies examine gametocytaemia in asymptomatic school chi...

The risk of pathogen transmission continues to increase significantly in the presence of tick vectors due to the trade of livestock across countries. In Ghana, there is a lack of data on the incidence of tick-borne pathogens that are of zoonotic and veterinary importance. This study, therefore, aimed to determine the prevalence of such pathogens in...

Introduction: Filth flies can mechanically transmit pathogens, some of which can cause significant diseases in humans and animals. Methods: This study aimed at isolating and identifying pathogenic fungi and intestinal parasites from flies sampled with sweep nets and fly traps from different dumpsites in a tertiary institution. Dumpsites at the vari...

PurposeTo determine the levels of knowledge, awareness and perception of malaria, and to determine the infection status among asymptomatic adults in selected districts.Methods This descriptive, cross-sectional study recruited 849 participants from seven districts in the malaria meso-endemic forest zone of Ghana. Questionnaires were administered to...

Introduction: Malaria and conditions associated with common haemoglobinopathies constitute a health threat to young children in sub-Saharan Africa. Malaria is known to exert some influence on common haemoglobin variants while haemoglobinopathies also exacerbate malarial infection especially in children as a result of anaemia and other conditions. A...

Background Worldwide, intestinal parasites significantly affect the health and production of pigs. Objective This study assessed the prevalence of Ascaris and Cryptosporidium infection in pigs in the Ejisu‐Juaben Municipality of Ghana. Method Faecal samples from two hundred (200) pigs on four different farms (labelled A, B, C, D) were processed u...

Habitat disturbance can have negative impacts on biodiversity, such as reducing species richness. The effects of habitat disturbances on parasite infections of host species, potentially altering their survival rate and thus abundance, are less well known. We examined the influence of forest logging in combination with seasonality, host abundance, h...

The identification of intestinal parasite of baboons (Papio anubis) and warthogs (Phacochoerus aethiopicus) was undertaken at the Mole National Park, Ghana. The main objective of the study was to determine the types and prevalence of intestinal parasites in baboons and warthogs in the Mole National Park. A total of nineteen (19) and twenty‐three (2...

Several intestinal parasites of baboons are of zoonotic importance, especially where there is considerable interaction between the baboons and humans. The identification of gastrointestinal parasite infections of baboons (Papio anubis) was undertaken at the Shai Hills Reserve Resort, Ghana. A total of 51 faecal samples were collected randomly from...

Neisseria gonorrhoeae antimicrobial resistance (AMR) surveillance is essential for tracking the emergence and spread of AMR strains in local, national and international populations. This is crucial for developing or refining treatment guidelines. N. gonorrhoeae multiantigen sequence typing (NG-MAST) is beneficial for describing the molecular epidem...

The aim of this study seeks to assess the quality of recreational waters in selected swimming pools in the Asuogyaman district in the Eastern Region, Ghana. Samples from three different swimming facilities, coded as VH, RS and SH were collected during the months of March 2018 through to August, 2018 and analyzed in the laboratory employing standard...

Water is very vital for the sustenance of life and according to World Health Organization; potable water should be free from any health risk. However due to in adequate supply of potable water, many rural dwellers have no choice but to depend on streams and rivers as source of drinking water which becomes the vehicle for the transmission of infecti...

Microbiological quality assurance has been employed in food industries for many years, to guarantee the quality of food products for human consumption, however, foodborne diseases continue to occur. This study sought to assess the microbial quality of cocoa products at various processing stages as well as the processing environment, in a typical co...

Malaria transmission within areas of wastewater irrigation activities was the focus of this study where seven thousand and seventeen (7017) progressive data from health facilities within seventy-seven (77) communities were assessed. Results indicated approximately 3698 and 3319 cases of malaria, respectively for areas of wastewater irrigation activ...

Background The lymphatic filariasis (LF) control programme has been on-going in Ghana since 2000 with mass drug administration (MDA) of ivermectin (IVM) and albendazole (ALB). Soil-transmitted helminth (STH) infections control is augmented within this programme. Therefore this study aimed to determine the efficacy of ALB against STH infections and...

This study investigated the effects of climatic variables, particularly, rainfall and temperature, on malaria incidence using time series analysis. Our preliminary analysis revealed that malaria incidence in the study area decreased at about 0.35% annually. Also, the month of November recorded approximately 21% more malaria cases than the other mon...

The lymphatic filariasis (LF) control programme has been on-going in Ghana since 2000 with mass drug administration (MDA) of ivermectin (IVM) and albendazole (ALB). Soil-transmitted helminth (STH) infections control is augmented within this programme. Therefore this study aimed to determine the efficacy of ALB against STH infections and impact of M...

Bacteriological, physicochemical and heavy metal analyses of treated water supply to the Kumasi Metropolis from the Barekese Headwork was carried out. Samples from BK4 and BK6 have their turbidity higher than the WHO acceptable limits for drinking water but the pH recorded were all within the limits of 6.5 to 8.5. Conductivity varied from 250.20 μS...

This study was carried out to assess the distribution of E. coli O157:H7 in salad foods from restaurants and street food vendors within the Kumasi Metropolis from January to April, 2013. A detailed and well-structured questionnaire was first administered to 500 vendors with emphasis on knowledge of personal hygiene and salad food preparation. A tot...

Arsenic poisoning has become one of the major environmental concerns in the world as millions of people have been exposed to excessive arsenic through contaminated drinking water. In this study, ICR mice were introduced to 0.8-4.8 mgL-1 arsenic, synonymous to arsenic detected from streams and soils in Buruli Ulcer endemic communities of the Amansie...

The Soil-Transmitted Helminth (STH) infections control programme has been on-going in Ghana since 2000 with mass drug administration (MDA) of albendazole (ALB) to school children. However, our research revealed, 100% cure rate with albendazole-levamisole (ALB-LEV) combination in hookworm population responding sub-optimally to ALB treatment in four...

Wastewater use for vegetable production is widespread across the cities of many developing countries. Studies on the microbial health risks associated with the practice have largely depended on faecal indicator organisms with potential underestimation or overestimation of the microbial health risks and disease burdens. This study assessed the Esche...

Background: The diagnosis of Pulmonary Tuberculosis (PTB) has mainly relied on sputum microscopy and culture. The use of molecular techniques such as the Polymerase Chain Reaction (PCR) and its overwhelming advantages compared with conventional diagnostic methodologies cannot be overemphasized. The main aim of this work was to compare the diagnosti...

Two hundred and seventy four asymptomatic Ghanaian school-children aged 5 to 17 years were screened for malaria parasites by examination of blood films. One hundred and fifty five microscopically-positive individuals were treated with dihydroartemisinin-piperaquine and followed for 3 weeks. Retrospective species-specific PCR of all 274 screened sam...

The diagnosis of Pulmonary Tuberculosis (PTB) has mainly relied on sputum microscopy and culture. The use of molecular techniques such as the Polymerase Chain Reaction (PCR) and its overwhelming advantages compared with conventional diagnostic methodologies cannot be overemphasized. The main aim of this work was to compare the diagnostic sensitivit...

This study assessed the die-off of Escherichia coli (E. coli) and Ascaris suum on lettuce (Great Lakes 118) and cabbage (Brassica oleracea var capitata) in wastewater-irrigated fields using comparative mathematical die-off models. The study revealed that none of the survival curves of E. coli and A. suum was best fitted with the log-linear model, i...

Abstract Background The existing metrics of malaria transmission are limited in sensitivity under low transmission intensity. Robust surveillance systems are needed as interventions to monitor reduced transmission and prevention of rapid reintroduction. Serological tools based on antibody responses to parasite and vector antigens are potential tool...

Assessment of malaria endemicity at different altitudes and transmission intensities, in the era of dwindling vector densities in the highlands, will provide valuable information for malaria control and surveillance. Measurement of serum anti-malarial antibodies is a useful marker of malaria exposure that indicates long-term transmission potential....

Background: The existing metrics of malaria transmission are limited in sensitivity under low transmission intensity. Robust surveillance systems are needed as interventions to monitor reduced transmission and prevention of rapid reintroduction. Serological tools based on antibody responses to parasite and vector antigens are potential tools for tr...

Plasmodium falciparum, the most virulent and deadly of all the malaria species is known to be genetically diverse. This cross–sectional study assessed the genetic diversity of P. falciparum parasites in pregnant women in the Offinso District. Blood samples of pregnant women, irrespective of their intermittent preventive treatment of malaria in preg...

Malaria infection during pregnancy causes maternal anaemia and placental parasitaemia both of which pose substantial risks to the mother, the foetus and the newborn. This study assessed the effects of intermittent preventive treatment (IPTp) using Sulphadoxine-Pyrimethamine (SP) to control malaria in pregnancy in the Offinso district, Ghana. Pregna...

Forest management practices which may represent various forms of disturbance regimes could influence liana species richness, abundance and relationship with their hosts. The study sought to determine the impacts of three management systems, namely, the Selection, Tropical Shelterwood and Post Exploitation Systems (SS, TSS and PES respectively) on l...

Treatment of malaria is being hampered by the emergence of drug resistant strains of malaria parasites. In this study, mutation specific polymerase chain reaction assays using 3\'-mismatched oligonucleotide primers which annealed to the wild or mutated parasites\' gene encoding dihydrofolate reductase-thymidylate synthase (DHFR-TS) were used to sur...

In a randomized, placebo-controlled trial in Ghana, 67 onchocerciasis patients received 200-mg/day doxycycline for 4-6 weeks, followed by ivermectin (IVM) after 6 months. After 6-27 months, efficacy was evaluated by onchocercoma histology, PCR and microfilariae determination. Administration of doxycycline resulted in endobacteria depletion and fema...

Lymphatic filariasis is a disease of considerable socioeconomic burden in the tropics. Presently used antifilarial drugs are able to strongly reduce transmission and will thus ultimately lower the burden of morbidity associated with the infection, however, a chemotherapeutic principle that directly induces a halt or improvement in the progression o...

Infection with the filarial nematode Onchocerca volvulus can lead to severe dermatitis, visual impairment, and ultimately blindness. Since the currently used drug, ivermectin does not have macrofilaricidal or strong permanent sterilising effects on the adult worm, more effective drugs are needed to complement the use of ivermectin alone. Wolbachia...

The study was aimed to find out whether T cells with a regulatory profile could regulate the secretion of IgG4. Using tetanus Ag we found that PBMC of healthy human donors responded to exogenous IL-10 by down-regulating IgG1 and increasing IgG4 secretion. IgE was not affected. To investigate the direct effect of IL-10-producing T cells on B cells,...

Different mechanisms underlie the phenomenon of peripheral tolerance. Recently, a new subset of CD4+ T cells, called T regulatory-1 (Tr1) cells, was described which show suppressor functions in vitro and in vivo and are characterized by a predominant production of IL-10 and/or TGF-beta. Tr1 cells have so far been generated experimentally in an IL-1...

T Regulatory-1 Cells Induce IgG4 Production by B Cells: Role of IL-10 Sedaminou Judith Gbenoudon, Esther Mettler, John Larbi and Achim Hoerauf The study was aimed to find out whether T cells with a regulatory profile could regulate the secretion of IgG4. Using tetanus Agwe found that PBMC of healthy human donors responded to exogenous IL-10 by d...