The contribution of community health education to sustainable control of the Neglected Zoonotic Diseases

Effective and sustainable control of the Neglected Zoonoses (NZDs) demands a One Health approach. NZDs largely impact on individuals in low- and middle-income countries, disproportionally affecting resource poor communities with poor access to veterinary and human health services and to clean water and which are intrinsically dependent on animals for their livelihoods. Many NZDs in humans can be treated, but treatment is often complex and expensive. Similarly, while tools for prevention of transmission may exist, they are complex and expensive to adopt at the scale required to be effective. The cost of intervention for NZDs is high when compared to the public health benefits alone, but costs are easily outweighed by full cross sector analysis and when monetary and non-monetary benefits to all stakeholders are considered. Education is a key tool, often overlooked in favor of more complex solutions for the control of NZDs. Successful education programs have been targeted to children of school age for Taenia solium in Kenya, schistosomiasis in Nigeria, and soil transmitted helminths in China. A Snakes and Ladders board game, designed to teach children about schistosomiasis and encourage compliance with mass deworming programs, deployed in Nigerian schools, showed a 67% increase in knowledge of praziquantel and 65% of children who had previously rejected treatment requested the drug at school. For soil transmitted helminths in China, presentation of health information in cartoon format rather than in poster format, showed post-assessment knowledge to be 90% higher. With the rise in affordable smart-phone technology, internet access and airtime in communities in low- and middle- income countries e-education is an increasingly attractive proposition as an intervention tool for the NZDs. The Vicious Worm, a computer based educational health tool that has been designed around the prevention of Taenia Solium has shown remarkable efficacy in affected communities in which it has been deployed with participants applying the principles learned in their communities. This review explores the successes and benefits of education as a control tool for the NZDs

Effects of cyclic nucleotides on midgut infections and maturation of T. b. brucei in G. m. morsitans

Cyclic nucleotide signalling through cyclic adenosine monophosphate (cAMP) is thought to play an important role in the transformation of the long slender (dividing) form to the short-stumpy (arrested) form in the mammalian bloodstream but the role of cyclic nucleotides in the tsetse-based part of the trypanosome life cycle is unknown. In a series of in vivo experiments, it was found that cyclic guanosine monophosphate (cGMP) but not cAMP could induce significantly higher rates of midgut infection in tsetse. Continuous feeding of either cGMP or cAMP to tsetse had no effect on rates of maturation of established midgut infections suggesting that these two parts of the life cycle in tsetse are not linked

Chapitre 18 - Trypanosomiase humaine et animale africaine

Introduction La gestion du risque de zoonoses résultant des interactions entre les animaux, les humains et l’environnement exige une action intégrée des secteurs de la santé humaine et animale, le soutien d’autres secteurs ou industries concernés par la gouvernance sanitaire et des apports clefs de la filière environnementale (Cook et al., 2004 ; Okello et al., 2011 ; Welburn, 2011 ; Zinsstag et al., 2012). Dans ..

Herd prevalence of bovine brucellosis and analysis of risk factors in cattle in urban and peri-urban areas of the Kampala economic zone, Uganda

<p>Abstract</p> <p>Background</p> <p>Human brucellosis has been found to be prevalent in the urban areas of Kampala, the capital city of Uganda. A cross-sectional study was designed to generate precise information on the prevalence of brucellosis in cattle and risk factors for the disease in its urban and peri-urban dairy farming systems.</p> <p>Results</p> <p>The adjusted herd prevalence of brucellosis was 6.5% (11/177, 95% CI: 3.6%-10.0%) and the adjusted individual animal prevalence was 5.0% (21/423, 95% CI: 2.7% - 9.3%) based on diagnosis using commercial kits of the competitive enzyme-linked immunosorbent assay (CELISA) for <it>Brucella abortus </it>antibodies. Mean within-herd prevalence was found to be 25.9% (95% CI: 9.7% - 53.1%) and brucellosis prevalence in an infected herd ranged from 9.1% to 50%. A risk factor could not be identified at the animal level but two risk factors were identified at the herd level: large herd size and history of abortion. The mean number of milking cows in a free-grazing herd (5.0) was significantly larger than a herd with a movement restricted (1.7, p < 0.001).</p> <p>Conclusions</p> <p>Vaccination should be targeted at commercial large-scale farms with free-grazing farming to control brucellosis in cattle in and around Kampala city.</p

Livestock network analysis for rhodesiense human African trypanosomiasis control in Uganda

Background: Infected cattle sourced from districts with established foci for Trypanosoma brucei rhodesiense human African trypanosomiasis (rHAT) migrating to previously unaffected districts, have resulted in a significant expansion of the disease in Uganda. This study explores livestock movement data to describe cattle trade network topology and assess the effects of disease control interventions on the transmission of rHAT infectiousness.Methods: Network analysis was used to generate a cattle trade network with livestock data which was collected from cattle traders (n = 197) and validated using random graph methods. Additionally, the cattle trade network was combined with a susceptible, infected, recovered (SIR) compartmental model to simulate spread of rHAT (Ro 1.287), hence regarded as “slow” pathogen, and evaluate the effects of disease interventions.Results: The cattle trade network exhibited a low clustering coefficient (0.5) with most cattle markets being weakly connected and a few being highly connected. Also, analysis of the cattle movement data revealed a core group comprising of cattle markets from both eastern (rHAT endemic) and northwest regions (rHAT unaffected area). Presence of a core group may result in rHAT spread to unaffected districts and occurrence of super spreader cattle market or markets in case of an outbreak. The key cattle markets that may be targeted for routine rHAT surveillance and control included Namutumba, Soroti, and Molo, all of which were in southeast Uganda. Using effective trypanosomiasis such as integrated cattle injection with trypanocides and spraying can sufficiently slow the spread of rHAT in the network.Conclusion: Cattle trade network analysis indicated a pathway along which T. b. rhodesiense could spread northward from eastern Uganda. Targeted T. b. rhodesiense surveillance and control in eastern Uganda, through enhanced public–private partnerships, would serve to limit its spread

Critical linkages between livestock production, livestock trade and potential spread of human African trypanosomiasis in Uganda:Bioeconomic herd modeling and livestock trade analysis

Background: Tsetse-transmitted human African trypanosomiasis (HAT) remains endemic in Uganda. The chronic form caused by Trypanosoma brucei gambiense (gHAT) is found in north-western Uganda, whereas the acute zoonotic form of the disease, caused by T. b. brucei rhodesiense (rHAT), occurs in the eastern region. Cattle is the major reservoir of rHAT in Uganda. These two forms of HAT are likely to converge resulting in a public health disaster. This study examines the intricate and intrinsic links between cattle herd dynamics, livestock trade and potential risk of spread of rHAT northwards. Methods: A bio-economic cattle herd model was developed to simulate herd dynamics at the farm level. Semi-structured interviews (n = 310), focus group discussions (n = 9) and key informant interviews (n = 9) were used to evaluate livestock markets (n = 9) as part of the cattle supply chain analysis. The cattle market data was used for stochastic risk analysis. Results: Cattle trade in eastern and northern Uganda is dominated by sale of draft and adult male cattle as well as exportation of young male cattle. The study found that the need to import draft cattle at the farm level was to cover deficits because of the herd structure, which is mostly geared towards animal traction. The importation and exportation of draft cattle and disposal of old adult male cattle formed the major basis of livestock movement and could result in the spread of rHAT northwards. The risk of rHAT infected cattle being introduced to northern Uganda from the eastern region via cattle trade was found to be high (i.e. probability of 1). Conclusion: Through deterministic and stochastic modelling of cattle herd and cattle trade dynamics, this study identifies critical links between livestock production and trade as well as potential risk of rHAT spread in eastern and northern Uganda. The findings highlight the need for targeted and routine surveillance and control of zoonotic diseases such as rHAT

Amplified fragment length polymorphism (AFLP) analysis of closely related wild and captive tsetse fly (Glossina morsitans morsitans) populations

<p>Abstract</p> <p>Background</p> <p>Tsetse flies (Diptera: Glossinidae) are vectors of trypanosomes that cause sleeping sickness in humans and nagana in livestock across sub-Saharan Africa. Tsetse control strategies rely on a detailed understanding of the epidemiology and ecology of tsetse together with genetic variation within and among populations. High-resolution nuclear genetic markers are useful tools for elucidation of the genetic basis of phenotypic traits. In this study amplified fragment length polymorphism (AFLP) markers were developed to analyze genetic variation in <it>Glossina morsitans morsitans </it>from laboratory and field-collected populations from Zimbabwe.</p> <p>Results</p> <p>A total of seven hundred and fifty one loci from laboratory and field populations of <it>G. m. morsitans </it>from Zimbabwe were genotyped using AFLP with seven primer combinations. Analysis identified 335 polymorphic loci. The two populations could be distinguished by cluster and principal components analysis (PCA) analysis, indicating that AFLP markers can be used to separate genetically similar populations; at the same time differences observed between laboratory and field populations were not very great. Among the techniques investigated, the use of acetone was the most reliable method of preservation of tsetse for subsequent extraction of high molecular weight DNA. An interesting finding was that AFLP also enabled robust within-population discrimination of male and female tsetse flies due to their different X chromosome DNA complements.</p> <p>Conclusions</p> <p>AFLP represents a useful additional tool to add to the suite of techniques currently available for the genetic analysis of tsetse populations and represents a useful resource for identification of the genetic basis of important phenotypic traits.</p

Spatial epidemiology of hospital-diagnosed brucellosis in Kampala, Uganda

<p>Abstract</p> <p>Background</p> <p>A retrospective case-control study was undertaken to examine the spatial risk factors for human brucellosis in Kampala, Uganda.</p> <p>Methods</p> <p>Information on age, sex and month of diagnosis was derived from records from plate agglutination tests undertaken at Mulago Hospital, Kampala. Information on Parishes (LC2s) where patients reside was sourced from the outpatient registration book. In-patient fracture cases were selected for use as controls using 1:1 matching based on the age, sex and month of diagnosis. The locations of cases and controls were obtained by calculating Cartesian coordinates of the centroids of Parish level (LC2) polygons and a spatial scan statistic was applied to test for disease clustering. Parishes were classified according to the level of urbanization as urban, peri-urban or rural.</p> <p>Results</p> <p>Significantly more females than males were found to show sero-positivity for brucellosis when compared with the sex ratio of total outpatients, in addition female brucellosis patients were found to be significantly older than the male patients. Spatial clustering of brucellosis cases was observed including around Mulago Hospital (radius = 6.8 km, <it>p </it>= 0.001). The influence of proximity to the hospital that was observed for brucellosis cases was not significantly different from that observed in the controls. The disease cluster was confounded by the different catchment areas between cases and controls. The level of urbanization was not associated with the incidence of brucellosis but living in a slum area was a significant risk factor among urban dwellers (odds ratio 1.97, 95% CI: 1.10-3.61).</p> <p>Conclusions</p> <p>Being female was observed to be a risk factor for brucellosis sero-positvity and among urban dwellers, living in slum areas was also a risk factor although the overall risk was not different among urban, peri-urban and rural areas of the Kampala economic zone.</p

Ixodid ticks of traditionally managed cattle in central Nigeria: where Rhipicephalus (Boophilus) microplus does not dare (yet?)

BACKGROUND: Ticks and tick-borne diseases (TBDs) undermine cattle fitness and productivity in the whole of sub-Saharan Africa, including Nigeria. The aim of this study was to document the composition of tick species, assessing the burden of infestation, in traditionally managed cattle in an area of central Nigeria where acaricides have not been used historically. METHODS: The study was carried out in September 2010 in 9 villages belonging to three neighbouring local government areas in Plateau State, Nigeria. In each village all visible adult ticks were collected from at least 15 cattle (mean number = 25). Collected ticks were preserved in 70% ethanol to be counted and morphologically identified to the species level. RESULTS: A total of 5011 ixodid ticks (1935 males and 3076 females) were collected from 228 cattle, comprising 14 calves, 33 juveniles, and 181 adults. Three tick genera (i.e., Amblyomma, Hyalomma, and Rhipicephalus, including the Boophilus sub-genus) and 11 species were identified. The most prevalent species was Rhipicephalus (Boophilus) decoloratus (41.4%), followed by Rhipicephalus (Boophilus) annulatus (15.4%), Rhipicephalus guilhoni (12.0%), Rhipicephalus (Boophilus) geigyi (7.6%), Hyalomma truncatum (7.4%), Amblyomma variegatum (6.3%), Rhipicephalus simus Group (4.0%), Rhipicephalus turanicus (1.2%), Rhipicephalus sanguineus (0.3%), Hyalomma rufipes (0.2%), and Rhipicephalus lunulatus (n = 1). Mean tick loads recorded were relatively high (22 ± 1.4), in spite of the practice of hand removal of ticks traditionally undertaken by the Fulani pastoralists in the area. Calves bore a significantly lower tick burden than adults (p = 0.004). Rhipicephalus (Boophilus) microplus was not found in the area, suggesting that the eastbound expansion of this tick species in West Africa, has not yet reached central Nigeria. CONCLUSIONS: This study ascertained the presence of a broad variety of cattle tick species, most of which are of veterinary importance. The presence of each tick species is correlated with the potential occurrence of tick-borne pathogens and suggestions for tick control in the area are considered. Results should assist the diagnosis of related TBDs in cattle as well as the strategic planning of cost-effective tick control