Stacey E. Lynch

Infection-interactions in Ethiopian village chickens

Chickens raised under village production systems are exposed to a wide variety of pathogens, and current or previous infections may affect their susceptibility to further infections with another parasite, and/or can alter the manifestation of each infection. It is possible that co-infections may be as important as environmental risk factors. However, in cross-sectional studies, where the timing of infection is unknown, apparent associations between infections may be observed due to parasites sharing common risk factors. This study measured antibody titres to 3 viral (Newcastle disease, Mareks disease and infectious bursal disease) and 2 bacterial (Pasteurella multocida and Salmonella) diseases, and the infection prevalence of 3 families of endo- and ecto-parasites (Ascaridida, Eimeria and lice) in 1056 village chickens from two geographically distinct populations in Ethiopia. Samples were collected during 4 cross-sectional surveys, each approximately 6 months apart. Constrained ordination, a technique for analysis of ecological community data, was used to explore this complex dataset and enabled potential relationships to be uncovered and tested despite the different measurements used for the different parasites. It was found that only a small proportion of variation in the data could be explained by the risk factors measured. Very few birds (9/1280) were found to be seropositive to Newcastle disease. Positive relationships were identified between Pasteurella and Salmonella titres; and between Mareks disease and parasitic infections, and these two groups of diseases were correlated with females and males, respectively. This may suggest differences in the way that the immune systems of male and female chickens interact with these parasites. In conclusion, we find that a number of infectious pathogens and their interactions are likely to impact village chicken health and production. Control of these infections is likely to be of importance in future development planning.

Genetic characterisation of infectious bursal disease virus isolates in Ethiopia

Graphical abstract This paper describes a molecular characterisation of IBD circulating in commercial and breeding poultry farms in Ethiopia. Ethiopian vvIBDVs are clustered phylogenetically with the African IBDV genetic lineage, independent of the Asian/European genetic.

Farmers’ willingness to pay for a village poultry vaccine service in Ethiopia: prospect for enhancing rural livelihoods

This research examines farmers’ willingness to pay for village poultry vaccine programmes using data from 400 household heads from two districts in Ethiopia, Horro and Jarso. The study applied a contingent valuation method to elicit farmers’ willingness to pay for village poultry vaccine services. Two hypothetical vaccine programmes were designed for Newcastle disease and Gumboro disease. Both parametric and non-parametric approaches were employed in data analysis. The results show that farmers recognise the benefits of the vaccine programme and that many would be willing to pay for it. Results from non-parametric estimates produced households’ mean willingness to pay Ethiopian Birr (ETB) 80 up to ETB 87 per year based on vaccine programme type. This demonstrates the potential and prospect of reducing the impact of infectious poultry diseases and enhancing rural livelihoods through village poultry. Exponential probit analysis revealed that farmers’ willingness to pay for village poultry vaccine service is influenced by age, education level, and region of respondents. Younger and more-educated farmers were more likely to pay for village poultry vaccine services and farmers from Horro, a relatively food secure and educated area, were more likely to pay than those from the less food secure Jarso district.