[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: 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.
[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.
Agricultural Systems 02/2007; · 2.50 Impact Factor
[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.
[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.
[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.
Transactions of the Royal Society of Tropical Medicine and Hygiene 05/2006; 100(4):354-62. · 1.82 Impact Factor
[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.
Revue d économie du développement 01/2006; 20(1):99-119.
[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
Revue d’économie du développement. 01/2006; 20(5):93-111.
[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.
Tropical Medicine & International Health 10/2005; 10(9):840-9. · 2.94 Impact Factor
[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.
Journal of Parasitology 01/2005; 90(6):1279-87. · 1.32 Impact Factor
[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.
Transactions of the Royal Society of Tropical Medicine and Hygiene 11/2004; 98(10):569-76. · 1.82 Impact Factor
[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.
[Show abstract][Hide abstract] ABSTRACT: For those with sleeping sickness, the consequences of delayed diagnosis include poor prognosis at treatment and an increased risk of tsetse infection. Data on their socio-demographic and clinical characteristics, health-seeking behaviour and delays in presentation and diagnosis were collected from 119 diagnosed cases of rhodesiense sleeping sickness in eastern Uganda. The median total delay, from onset of the illness to diagnosis, was 60 days. The median service-provider delay (30 days) was markedly longer than the median patient delay (17 days). Each of these delays was, however, considerable and independently associated with patients presenting with late-stage sleepiness, giving odds ratios and (95% confidence intervals) of 7.29 (3.10-17.14) and 2.98 (1.38-6.43), respectively. A blood examination at the first visit was also associated with the service-provider delay (odds ratio = 0.45; 95% confidence interval = 0.22-0.95). Most of the patients (77.4%) had either been referred to the local sleeping-sickness hospital by other members of their community or presented at the hospital on their own initiative; few had been referred by other components of the local health system. The results are disappointing, not only in showing long delays in diagnosis (and therefore in treatment) but also in indicating that much of the delay is attributable to the service provider failing to diagnose sleeping sickness among symptomatic individuals.
Annals of Tropical Medicine and Parasitology 07/2004; 98(4):339-48. · 1.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In a tsetse-infested area of Kenya, we characterised veterinary-drug outlets based on personnel and business characteristics to assess their capacities to provide clinical veterinary services. Structured questionnaires were administered to the retailers and sought information on the characteristics of the owners, salespersons and businesses. A total of 41 retail outlets (20 agro-veterinary, 11 pharmacy, and 10 general shops) were identified. There was poor response to questions on owner characteristics. Proprietors, who had no more than secondary education owned 15 out of 28 shops. Few shops (4/29) were owned by proprietors, who had professional qualifications (in animal health). Most salespersons had only secondary education but no qualifications. Animal-health assistants (AHAs), veterinarians and manufacturer's package inserts (drug leaflets) were the preferred information sources for the retailers. We concluded that drug retailers were poorly equipped with the technical knowledge necessary for drug dispensation and advice.
Preventive Veterinary Medicine 05/2004; 63(1-2):29-38. · 2.39 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study assessed the degree of isometamidium resistance of trypanosomes infecting cattle in the upper Didessa valley of western Ethiopia. An initial prevalence study was conducted to identify sites with a high risk of trypanosmosis in cattle. The trypanosome prevalence varied widely, with two sites, Kone (21.3%) and Village 1 settlement (15%) having a relatively high prevalence based on the phase-contrast buffy-coat technique (BCT). In the highest risk area, the Kone settlement, an isometamidium block treatment study was conducted from April to June 2001. A total of 300 cattle were included in this study, 100 from each of three villages (Cheleleki, Kolu and Burka). At day minus 14 of the study, all 300 cattle were treated with diminazene aceturate at 7 mg/kg body weight. Subsequently, these cattle were ear-tagged and randomly assigned into two groups, 50 controls and 50 for isometamidium treatment in each village. Fourteen days later (day 0), the 50 treatment cattle were given isometamidium chloride at 1 mg/kg body weight. Both groups of cattle were then examined for trypanosome parasites using BCT every 14 days until 84 days. The two indices used in assessing isometamidium resistance, namely the proportion of infections during an 8-week follow-up period and the ratio of mean hazards in an isometamidium treated versus untreated group, provided consistent results across the three villages. In Burka village, both indices demonstrated the presence of isometamidium resistance trypanosome infections while in Cheleleki and Kolu villages, both indices did not indicate significant levels of resistance. There were significant differences between the Kaplan-Meier survival estimates of the control and treatment groups in Cheleleki (P < 0.01) and Kolu (P < 0.05) but not in Burka (P > 0.05).
[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.