[Show abstract][Hide abstract] ABSTRACT: Smallholder livestock keepers represent almost 20% of the world population and steward most of the agricultural land in the tropics. Observed and expected increases in future demand for livestock products in developing countries provide unique opportunities for improving livelihoods and linked to that, improving stewardship of the environment. This cannot be a passive process and needs to be supported by enabling policies and pro-poor investments in institutional capacities and technologies. Sustaining intensification of smallholder livestock systems must take into account both social and environmental welfare and be targeted to sectors and areas of most probable positive social welfare returns and where natural resource conditions allow for intensification. Smallholders are competitive in ruminant systems, particularly dairy, because of the availability of family labour and the ability of ruminants to exploit lower quality available roughage. Smallholders compete well in local markets which are important in agriculturally-based or transforming developing countries. However, as production and marketing systems evolve, support to smallholders to provide efficient input services, links to output markets and risk mitigation measures will be important if they are to provide higher value products. Innovative public support and links to the private sector will be required for the poor to adapt and benefit as systems evolve. Likewise targeting is critical to choosing which systems with livestock can be intensified. Some intensive river basin systems have little scope for intensification. More extensive rain-fed systems, particularly in Africa, could intensify with enabling policies and appropriate investments. In more fragile environments, de-intensification is required to avoid irreversible damage to ecosystems. Attention to both social and environmental sustainability are critical to understanding trade-offs and incentives and to bridging important gaps in the perspectives on livestock production between rich and poor countries and peoples. Two specific examples in which important elements of sustainable intensification can be illustrated, smallholder dairy systems in East Africa and South Asia and small ruminant meat systems in Sub-Saharan Africa, are discussed.
Full-text · Article · May 2010 · Livestock Science
[Show abstract][Hide abstract] ABSTRACT: Farmers in mixed crop-livestock systems produce about half of the world's food. In small holdings around the world, livestock are reared mostly on grass, browse, and nonfood biomass from maize, millet, rice, and sorghum crops and in their turn supply manure and traction for future crops. Animals act as insurance against hard times and supply farmers with a source of regular income from sales of milk, eggs, and other products. Thus, faced with population growth and climate change, small-holder farmers should be the first target for policies to intensify production by carefully managed inputs of fertilizer, water, and feed to minimize waste and environmental impact, supported by improved access to markets, new varieties, and technologies.
[Show abstract][Hide abstract] ABSTRACT: Over 85% of all milk sales on Kenya pass through informal channels. The extent of the risk posed by the sale of this raw milk to human health in respect to brucellosis is unknown. This paper presents the results of a study on the occurrence of antibodies to Brucella abortus in milk from households consuming raw unpasteurized milk and market agent selling the same. Four hundred thirty four (434) raw milk samples from consumer households and 508 from informal market agents were collected between January 1999 and January 2000 from Nakuru /Narok and Nairobi/Kiambu. Milk agents sampled included co-operative societies, milk collecting centers and self-help groups, milk bars, shops and kiosks and mobile traders on foot, bicycle or motorized transport. In addition, 147 samples from the formal market chain (pasteurized) were collected. All the samples from the samples were screened for antibodies to Brucella abortus using ELISA and Milk Ring Test (MRT), except for the formal milk that was tested using ELISA only. Five percent of the consumer household samples and 4% of the samples form informal milk market agents tested positive on ELISA. There was poor agreement between the two antibody surrogate tests (Kappa =0.40, 95% confidence interval =0.19-0.60). ELISA detected 3.2% more samples from consumer households and 0.4% from informal market agents than MRT. Of the formal market samples, 16.4% were positive. Ways of reducing the risk of contracting brucellosis from drinking raw milk are proposed. The Kenya Veterinarian Vol. 27 2004: pp. 18-21
[Show abstract][Hide abstract] ABSTRACT: Factors associated with growth and weight gains were examined in a prospective observational study that was conducted in 5 cohorts of female calves. A total of 225 calves on 1888 smallholder dairy farms were observed a period of one and a half years. The calves were distributed in 5 agro-ecological zones (AEZ) –grazing strata namely: Upper Midlands (UM)1, zerograzing, UM1 open-grazing, UM2, UM4 zero grazing and UM 4 open grazing. The calves were recruited within the first year of study that was conducted between March 1995 and August 1996. During each visit, the calves were weighed and data on calf management practice on the farm during the visits were also recorded. The overall mean daily weight gain were 0.26 kg and 0.25kg in UM1 zero-grazing and UM 1 open grazing respectively, 0.29 kg in UM2 and 0.26 kg and 0.24kg in UM4 zero-grazing and UM4 open grazing respectively. The main factors associated with calf mean dairy weight gains were mainly age of calf, concentrate feeds, T.parva antibodies, general calf sickness and occurrence of East Coast Fever. The Kenya Veterinarian Vol. 25 2002: pp. 36-39
[Show abstract][Hide abstract] ABSTRACT: This paper describes the development, design, dissemination and evaluation of a communication intervention designed to promote appropriate usage of trypanocidal drugs in trypanosomiasis endemic areas of western and coastal Kenya. Following a baseline study on current trypanosomiasis knowledge, attitudes and practices by smallholder farmers, a communication intervention strategy was developed involving dissemination through school children, village elders, animal health centres and Agrovet shops, and using layered messages in posters and leaflets. A participatory research approach was used to develop, design and assess the impact of animal health messages on the control of bovine trypanosomiasis for smallholder farmers in tsetse and trypanosomiasis endemic areas in Busia (two administrative divisions) and Kwale Districts (two administrative divisions) of Kenya. Communication intervention materials (in poster and leaflet formats) were developed and disseminated to residents in villages in one administrative division in each district (intervention area) while those from the other division in each district were not deliberately exposed to the animal health messages (control area). Several communication impact indicators were derived and these were measured 4–6 weeks after dissemination of the print media through questionnaires on trypanosomiasis knowledge administered to school children and cattle-keeping smallholders in the intervention and control study sites.School children’s post-communication intervention trypanosomiasis signs knowledge was much higher than that observed during the pre-communication intervention survey. More trypanocides were named by school children during the post-intervention questionnaire survey compared to those known during the pre-intervention survey.The trypanosomiasis signs knowledge score obtained by the smallholder farmers exposed to the extension materials was higher than that obtained by those not exposed to them. Similarly, farmers’ exposure to extension materials resulted in higher trypanocidal drug knowledge scores among exposed farmers than among those not exposed.These results indicate that over the period monitored, the routes (i.e. school children, village elders, animal health centres and Agrovet shops) and media (posters and leaflets) selected were effective in promoting a significant increase in knowledge of trypanosomiasis, its causes and ways of dealing with it among livestock keepers.
Full-text · Article · Feb 2007 · Agricultural Systems
[Show abstract][Hide abstract] ABSTRACT: Sleeping sickness is a parasitic, vector-borne disease, carried by the tsetse fly and prevalent in sub-Saharan Africa. The disease continues to pose a public health burden in Uganda, which experienced a widespread outbreak in 1900-1920, and a more recent outbreak in 1976-1989. The disease continues to spread to uninfected districts.
This paper compares the spatial distributions of sleeping in Uganda for the 1900-1920 outbreak period with current disease foci, and discusses information gaps and implications arising for future research, prevention and control.
Population census records for 1911 and sleeping sickness records from Medical and Sanitary Reports of the Ugandan Protectorate for 1905-1936 were extracted from the Uganda Archives. Current sleeping sickness distribution data were provided by the Ministry of Health, Uganda. These were used to develop sleeping sickness distribution maps for comparison between the early 1900s and the early 2000s.
The distribution of sleeping sickness from 1905-1920 shows notable differences compared to the current distribution of disease. In particular, archival cases were recorded in south-west and central Uganda, areas currently free of disease. The disease focus has moved from lakeshore Buganda (1905-1920) to the Busoga and south-east districts.
Archival sleeping sickness distributions indicate the potential for a much wider area of disease risk than indicated by current disease foci. This is compounded by an absence of tsetse distribution data, continued political instability in north-central Uganda, continued spread of disease into new districts, and evidence of the role of livestock movements in spreading the parasite. These results support concerns as to the potential mergence of the two disease foci in the south-east and north-west of the country.
Full-text · Article · Jan 2007 · African health sciences
[Show abstract][Hide abstract] ABSTRACT: This chapter explores the impacts of climate change, human population growth and expected disease control activities on tsetse
distribution and trypanosomiasis risk in five agro-ecological environments in sub-Saharan Africa to 2050. These changes will
tend to contract areas under trypanosomiasis risk continent-wide; however, this trend will not be uniform. The greatest decrease
in the impacts of animal trypanosomiasis will occur in the semi-arid and sub-humid zones of West Africa, where the climate
will be drier, human population will increase and disease control will have greater impacts. The risk of animal trypanosomiasis
will also decline in many but not all areas of Ethiopia and eastern and southern Africa. The disease situation in the humid
zone of central and western Africa will be less changed. Sleeping sickness, particularly the gambiense type, will continue,
as now, to be a major problem, if concerted control efforts are not implemented.
[Show abstract][Hide abstract] ABSTRACT: Sleeping sickness re-emerged in southeastern Uganda in the 1970s and remains a public health problem. It has continued to spread north into new districts, and gaps remain in the understanding of the causes of its spread and distribution. We report the distribution and magnitude of sleeping sickness in southeastern Uganda from 1970 to 2003. Data were collected from records of the Ugandan Ministry of Health, individual sleeping sickness treatment centers, and interviews with public health officials. Data were used to develop incidence maps over time, conduct space-time cluster detection analyses, and develop a velocity vector map to visualize spread of sleeping sickness over time in southeastern Uganda. Results show rapid propagation of sleeping sickness from its epicenter in southern Iganga District and its spread north into new districts and foci.
Full-text · Article · Jun 2006 · Emerging infectious diseases
[Show abstract][Hide abstract] ABSTRACT: Geographic information systems (GIS) and remote sensing were used to identify villages at high risk for sleeping sickness, as defined by reported incidence. Landsat Enhanced Thematic Mapper (ETM) satellite data were classified to obtain a map of land cover, and the Normalised Difference Vegetation Index (NDVI) and Landsat band 5 were derived as unclassified measures of vegetation density and soil moisture, respectively. GIS functions were used to determine the areas of land cover types and mean NDVI and band 5 values within 1.5 km radii of 389 villages where sleeping sickness incidence had been estimated. Analysis using backward binary logistic regression found proximity to swampland and low population density to be predictive of reported sleeping sickness presence, with distance to the sleeping sickness hospital as an important confounding variable. These findings demonstrate the potential of remote sensing and GIS to characterize village-level risk of sleeping sickness in endemic regions.
Full-text · Article · May 2006 · Transactions of the Royal Society of Tropical Medicine and Hygiene
[Show abstract][Hide abstract] ABSTRACT: Four Trypanosoma (T.) congolense reference clones with known isometamidium sensitivity and 16 T. congolense stocks from cattle in Kénédougou in south-western Burkina Faso, an area with known history of drug resistance, were characterised with the standard mouse test (SMT) and the drug incubation infectivity test (DIIT). All field stocks from Kénédougou were resistant to 1.0 mg/kg bw isometamidium in the SMT. Fourteen stocks (87.5%) also proved to be refractory to 10 mg/kg bw. Testing with the DIIT confirmed the results of the SMT. By comparison to reference clones, all the Kénédougou populations expressed high levels of resistance to isometamidium.
[Show abstract][Hide abstract] ABSTRACT: This paper analyzes the strategies of farmers in Kénédougou province to tackle African Animal Trypanosomosis (AAT). Using economic, entomological, and parasitological data collected by multidisciplinary team, we operate a binary Logit model to evaluate the probability of choice between animal health professionals and non professionals. The results show that economic and environmental variables contribute jointly to explain the choice between professional and non professional. The prevalence of trypanosomosis, and farm size affect positively the choice of farmers. However, farmers in crop production systems and producers who are far from the location of animal health professionals are slightly willing to choose their services for AAT control. Animal development policy should pay attention to physically and economic access to trypanocides in order to mitigate the impact of AAT on the productivity of farms.
Preview · Article · Jan 2006 · Revue d économie du développement
[Show abstract][Hide abstract] ABSTRACT: This paper analyses the strategies of farmers in the Kénédougou province to control African Animal Trypanosomosis (AAT). Using economic, entomological, and parasitological data collected by a multidisciplinary team, we operated a binary Logit model to evaluate the probability of choice between animal health professionals and non-professionals. The results show that economic and environmental variables contributed jointly to explain the choice between professionals and non-professionals in the study area. The prevalence of trypanosomosis, and farm size affect positively and significantly the choice of farmers to use an animal health professional. However, farmers in crop production systems, and distance both negatively affect the willingness to use the services of an animal health professional. Pastoral development policies should pay attention to improving economic and geographical access to veterinary drugs in order to mitigate the impact of AAT on the productivity of farms. JEL Classification: D01, D21
Preview · Article · Jan 2006 · Revue d économie du développement
[Show abstract][Hide abstract] ABSTRACT: As part of a study to assess zoonotic milk-borne health risks, seasonal survey data and unpasteurized milk samples were collected between January 1999 and February 2000 from randomly selected informal milk market agents (220 and 236 samples in the dry and wet seasons, respectively) and from households purchasing raw milk (213 and 219 samples in the dry and wet seasons, respectively) in rural and urban locations in central Kenya and screened for antibodies to Brucella abortus (B. abortus) and presence of Escherichia coli (E. coli) O157:H7. The latter was assessed based on samples from consumer households only. Antibodies to B. abortus were screened using the indirect antibody Enzyme Linked Immunosorbent Assay (ELISA) and the Milk Ring Test (MRT). The presence of E. coli O157:H7 was assessed by culture, biochemical characterisation, serological testing for production of verocytotoxin one (VT1) and two (VT2) and polymerase chain reaction (PCR) analysis for the presence of genes encoding for the toxins. The prevalence of antibodies to B. abortus varied considerably ranging from none in milk sold in small units and originating from intensive production systems to over 10% in samples that were bulked or originating from extensive production systems. E. coli O157:H7 was isolated from two samples (0.8%), one of which produced VT1. All urban consumers (100%) and nearly all rural consumers (96%) of marketed milk boiled the milk before consumption, mainly in tea, thus greatly reducing chances of exposure to live pathogens and potential health risks.
[Show abstract][Hide abstract] ABSTRACT: To formally quantify the level of under-detection of Trypanosoma brucei rhodesiense sleeping sickness (SS) during an epidemic in Uganda, a decision tree (under-detection) model was developed; concurrently, to quantify the subset of undetected cases that sought health care but were not diagnosed, a deterministic (subset) model was developed. The values of the under-detection model parameters were estimated from previously published records of the duration of symptoms prior to presentation and the ratio of early to late stage cases in 760 SS patients presenting at LIRI hospital, Tororo, Uganda during the 1988--1990 epidemic of SS. For the observed early to late stage ratio of 0.47, we estimate that the proportion of under-detection in the catchment area of LIRI hospital was 0.39 (95% CI 0.37--0.41) i.e. 39% of cases are not reported. Based on this value, it is calculated that for every one reported death of SS, 12.0 (95% CI 11.0--13.0) deaths went undetected in the LIRI hospital catchment area - i.e. 92% of deaths are not reported. The deterministic (subset) model structured on the possible routes of a SS infection to either diagnosis or death through the health system or out of it, showed that of a total of 73 undetected deaths, 62 (CI 60-64) (85%) entered the healthcare system but were not diagnosed, and 11 (CI 11--12) died without seeking health care from a recognized health unit. The measure of early to late stage presentation provides a tractable measure to determine the level of rhodesiense SS under-detection and to gauge the effects of interventions aimed at increasing treatment coverage.
Full-text · Article · Oct 2005 · Tropical Medicine & International Health
[Show abstract][Hide abstract] ABSTRACT: Sleeping sickness continues to be a significant public health burden in southeastern Uganda. Continued spread of the disease into new areas of Uganda highlights our inability to understand and predict the distribution of infection. Multiple factors influence the distribution of sleeping sickness, including climate, land cover, cattle movements, prevention and control activities, and social conflict. We draw on a systems approach to conceptualize and characterize the multiple interacting forces and processes that influence the spatial and temporal dynamics of sleeping sickness in Uganda. This synthesis reveals a complex system of interactions among human and biophysical systems, feedback, and scale dependence. We identify some common analytical modeling approaches relative to our system characterization and identify opportunities for sleeping sickness research and improved understanding of disease dynamics in Uganda.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to apply transition models to distinguish between factors associated with both incident and persistent trypanosome infections. Data collected from 1561 cattle were analyzed from a long-term study involving 8 herds in which both trypanosome infections (a total of 56,931 cattle sampling-months) and tsetse (Glossina spp.) challenge were monitored monthly from March 1986 to March 1998. Both pour-on and insecticide-target tsetse control programs and mass treatment with diminazene aceturate before tsetse control were associated with significant decreases in both incidence and persistence of trypanosome infection relative to noncontrol periods, as were seasonal and sex effects. The magnitudes of the effects were, however, often different for new and persistent infections. For persistence of infection, there were 2 trends. In general, the duration of infection increased during the study, despite the regular treatment with diminazene aceturate. The transition model had 2 major benefits. The first was to identify an increasing duration of infections with time, taking into account other factors associated with increasing infection risk. The second was to highlight different patterns in the effects of certain factors on new and persistent trypanosome infections.
Full-text · Article · Jan 2005 · Journal of Parasitology
[Show abstract][Hide abstract] ABSTRACT: The risk of consuming marketed milk containing antimicrobial residues was investigated by testing 854 unpasteurized and 110 pasteurized milk samples collected from contrasting locations, market outlets and consumer households in Kenya during 1999 and 2000. The Charm-AIM screening kit used detected antimicrobial residues in up to 16% of marketed milk samples, suggesting an average risk of exposure by consumers of up to five times every month. Higher prevalence levels of the residues were mainly associated with samples obtained lower in the market chain before bulking. Agreement between the Charm-AIM and Charm-SL test, that was used to specifically confirm the presence of β-lactams and tetracyclines, was poor beyond 72 h following drug administration due to differences in detectable limits of the tests.
[Show abstract][Hide abstract] ABSTRACT: We have carried out a study of risk factors for early detection of Trypanosoma brucei rhodesiense sleeping sickness. Records of sleeping sickness patients from 1987 to 2001 from Tororo and Busia districts in Uganda were reviewed for their village of origin and clinical stage (early or late). All villages that reported sleeping sickness and fixed post-diagnostic sleeping sickness health units in Tororo and Busia districts were geo-referenced. The spatial distribution of early and late stage patient detection by health units was analysed using Geographical Information Systems (GIS). Of 1316 sleeping sickness patients admitted at the Livestock Health Research Institute and Busolwe hospitals and Lumino health centre from Tororo and Busia districts, 471 (35.8%) were early stage, 825 (62.7%) were late stage, while 20 (1.5%) were not staged. Five hundred and eighty-five (44.5%) came from within a 10 km radius of the reporting health units. After multivariate analysis, the proportion of early stage patients detected was found to be significantly associated with patients originating from within a 10 km radius of the health unit (P < 0.01), with adults (>19 years) (P < 0.01), and with annual parish incidence (P < 0.01). Application of GIS and the early to late stages ratio are an informative and powerful means of determining efficiency of surveillance of sleeping sickness.
Full-text · Article · Nov 2004 · Transactions of the Royal Society of Tropical Medicine and Hygiene
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to assess, whether polymerase chain reaction (PCR) allows sensitive screening of treatment failure suspicions in areas, where drug resistance against African animal trypanosomosis (AAT) appears to be a problem. PCR was used to detect trypanosome infections prior to, 14 and 28 days after controlled treatment of 738 cattle from 10 villages in Kénédougou, Burkina Faso with isometamidium chloride and diminazene aceturate. Using three sets of primers, PCR was three-four times more sensitive and better at species identification, than standard microscopic examination. The better sensitivity and species specificity of PCR have important advantages for drug resistance studies in the field.