Judy M. Bettridge

Distribution of Borrelia burgdorferi sensu lato in Ixodes ricinus Populations Across Central Britain

Lyme borreliosis is rapidly emerging in the United Kingdom, with over 1000 cases per annum now reported. Lyme borreliosis is caused by the Borrelia burgdorferi sensu lato (s.l.) group of spirochetes, which are transmitted by ixodid ticks. In the United Kingdom, Ixodes ricinus is recognized as the principal vector of the spirochetes, and this tick species is widely distributed across the country. However, as yet, it is unclear whether the distribution of B. burgdorferi essentially mirrors that of its vector, or if there are marked differences between the 2. The aim of this survey was to investigate the prevalence of B. burgdorferi in I. ricinus populations across northern England, north Wales, and the Scottish Border region. We surveyed for questing I. ricinus nymphs and adults at 17 sites, encountering ticks at 12. At 8 sites, large numbers (>160) ticks were collected, and at 3 of these sites B. burgdorferi infection prevalence was significantly higher (>7.5%) than the other 5 (<1.0%). Habitat type was associated with B. burgdorferi prevalence, with ticks from deciduous and mixed woodland being significantly more likely to be infected than those from other habitat types. Identification of infecting Borrelia species indicated that Borrelia valaisiana was the most common and widespread species encountered. B. garinii was common at sites where infection prevalence was high, and B. afzelii was also occasionally encountered at these sites. The survey revealed a surprisingly uneven distribution of B. burgdorferi s.l. across the region, thereby indicating that the presence of ticks does not necessarily mean the presence of the pathogen. Indeed, the spirochete appears to be absent or very rare at some sites where ticks are abundant.

Participatory evaluation of chicken health and production constraints in Ethiopia.

Highlights • We examine chicken health and production constraints with backyard and semi-intensive producers in Ethiopia.• Participants identified 9 categories of constraints: the most important overall were disease and access to feed.• Despite generally detailed knowledge of disease risk factors, biosecurity measures were lacking or ineffective.• Producers reported difficulty accessing veterinary services, despite their proximity to such expertise.• Although many of these constraints may be viewed as technical issues to be overcome, our findings highlight underlying social factors that must also be addressed.

A Survey of UK Healthcare Workers' Attitudes on Volunteering to Help with the Ebola Outbreak in West Africa

Objective To understand the barriers and enablers for UK healthcare workers who are considering going to work in the current Ebola outbreak in West Africa, but have not yet volunteered. Design After focus group discussions, and a pilot questionnaire, an anonymous survey was conducted using SurveyMonkey to determine whether people had considered going to West Africa, what factors might make them more or less likely to volunteer, and whether any of these were modifiable factors. Participants The survey was publicised among doctors, nurses, laboratory staff and allied health professionals. 3109 people answered the survey, of whom 472 (15%) were considering going to work in the epidemic but had not yet volunteered. 1791 (57.6%) had not considered going, 704 (22.6%) had considered going but decided not to, 53 (1.7%) had volunteered to go and 14 (0.45%) had already been and worked in the epidemic. Results For those considering going to West Africa, the most important factor preventing them from volunteering was a lack of information to help them decide; fear of getting Ebola and partners’ concerns came next. Uncertainty about their potential role, current work commitments and inability to get agreement from their employer were also important barriers, whereas clarity over training would be an important enabler. In contrast, for those who were not considering going, or who had decided against going, family considerations and partner concerns were the most important factors. Conclusions More UK healthcare workers would volunteer to help tackle Ebola in West Africa if there was better information available, including clarity about roles, cover arrangements, and training. This could be achieved with a well-publicised high quality portal of reliable information.

Signature of artificial selection and ecological landscape on morphological structures of Ethiopian village chickens

Village chickens have been kept for millennia under patronage of smallholder farmers. Our study was intended at dissecting the signature of artificial selection and ecological variation on morphological structures of Ethiopian village chickens. This report was based on visual traits of 798 chickens and a concise one-to-one interview of 399 farmers for their preferences on chicken morphology. Significant population-specific differences in morphological counts were commonly found for rare morphological variants. Most of them were frequently seen in Jarso chickens, while some of them unique to Jarso chickens. This might be explained by the effect of location-specific evolutionary forces and differences in their breeding histories. The high within population variation in the frequency of morphological counts was observed among these panmictic chicken populations largely evolved under uncontrolled mating. Single comb was not (less) preferred by majority of the farmers (93.8 percent); it was thus present at a low frequency (26.7 percent). Farmers have shown high preference for yellow shank (42.3 percent), which was then frequently observed (61.1 percent). The reported reasons for morphological likeness were visual appeal, market demand and cultural and religious values. The absence of significant variation in preferences for chicken morphology among communities between the two study sites was attributed to their multifunctional needs.

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.

Genome-wide association studies of immune, disease and production traits in indigenous chicken ecotypes

BackgroundThe majority of chickens in sub-Saharan Africa are indigenous ecotypes, well adapted to the local environment and raised in scavenging production systems. Although they are generally resilient to disease challenge, routine vaccination and biosecurity measures are rarely applied and infectious diseases remain a major cause of mortality and reduced productivity. Management and genetic improvement programmes are hampered by lack of routine data recording. Selective breeding based on genomic technologies may provide the means to enhance sustainability. In this study, we investigated the genetic architecture of antibody response to four major infectious diseases [infectious bursal disease (IBDV), Marek’s disease (MDV), fowl typhoid (SG), fowl cholera (PM)] and resistance to Eimeria and cestode parasitism, along with two production traits [body weight and body condition score (BCS)] in two distinct indigenous Ethiopian chicken ecotypes. We conducted variance component analyses, genome-wide association studies, and pathway and selective sweep analyses.ResultsThe large majority of birds was found to have antibody titres for all pathogens and were infected with both parasites, suggesting almost universal exposure. We derived significant moderate to high heritabilities for IBDV, MDV and PM antibody titres, cestodes infestation, body weight and BCS. We identified single nucleotide polymorphisms (SNPs) with genome-wide significance for each trait. Based on these associations, we identified for each trait, pathways, networks and functional gene clusters that include plausible candidate genes. Selective sweep analyses revealed a locus on chromosome 18 associated with viral antibody titres and resistance to Eimeria parasitism that is within a positive selection signal. We found no significant genetic correlations between production, immune and disease traits, implying that selection for altered antibody response and/or disease resistance will not affect production.ConclusionsWe confirmed the presence of genetic variability and identified SNPs significantly associated with immune, disease and production traits in indigenous village chickens. Results underpin the feasibility of concomitant genetic improvement for enhanced antibody response, resistance to parasitism and productivity within and across indigenous chicken ecotypes.

Zoonotic disease risk perceptions in the British veterinary profession

Abstract In human and veterinary medicine, reducing the risk of occupationally-acquired infections relies on effective infection prevention and control practices (IPCs). In veterinary medicine, zoonoses present a risk to practitioners, yet little is known about how these risks are understood and how this translates into health protective behaviour. This study aimed to explore risk perceptions within the British veterinary profession and identify motivators and barriers to compliance with IPCs. A cross-sectional study was conducted using veterinary practices registered with the Royal College of Veterinary Surgeons. Here we demonstrate that compliance with IPCs is influenced by more than just knowledge and experience, and understanding of risk is complex and multifactorial. Out of 252 respondents, the majority were not concerned about the risk of zoonoses (57.5%); however, a considerable proportion (34.9%) was. Overall, 44.0% of respondents reported contracting a confirmed or suspected zoonoses, most frequently dermatophytosis (58.6%). In veterinary professionals who had previous experience of managing zoonotic cases, time or financial constraints and a concern for adverse animal reactions were not perceived as barriers to use of personal protective equipment (PPE). For those working in large animal practice, the most significant motivator for using PPE was concerns over liability. When assessing responses to a range of different “infection control attitudes”, veterinary nurses tended to have a more positive perspective, compared with veterinary surgeons. Our results demonstrate that IPCs are not always adhered to, and factors influencing motivators and barriers to compliance are not simply based on knowledge and experience. Educating veterinary professionals may help improve compliance to a certain extent, however increased knowledge does not necessarily equate to an increase in risk-mitigating behaviour. This highlights that the construction of risk is complex and circumstance-specific and to get a real grasp on compliance with IPCs, this construction needs to be explored in more depth.

Small ruminant pasteurellosis in Tigray region, Ethiopia: marked serotype diversity may affect vaccine efficacy

The aim of this study was to investigate the prevalent Bibersteinia, Mannheimia and Pasteurella serotypes, risk factors and degree of serotype co-infections in sheep and goats in the Tigray region of Ethiopia. Serum was collected from 384 sheep and goats from the Tanqua-Abergelle district of Tigray region using cross-sectional random sampling. An indirect haemagglutination test was used for serotyping. Risk factors for infections were evaluated by logistic regression. Potential clustering of multiple serotypes within individual animals due to common risk factors was evaluated by redundancy analysis. Eight serotypes were identified: all studied animals were serologically positive for at least one serotype. Overall, 355 (92·45%) of the animals were infected by four or more serotypes. Of the five risk factors studied, peasant association (PA), animal species, age (serotype A1), and bodyweight (serotype T15) were significantly associated with infection, but sex was not significant. Only PA explained a significant proportion of the variation (adjusted R 2 = 0·16) in the serological responses. After the effect of PA was accounted for, T3 and T4; A7 and Pasteurella multocida A; and A7 and T10 were positively correlated for co-infection, while T4 and T10 were less likely to be found within the same animal. Diverse serotypes were circulating in the Tigray region and could be a challenge in selecting serotypes for vaccine.

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.

Detection of infectious bronchitis virus 793B, avian metapneumovirus, Mycoplasma gallisepticum and Mycoplasma synoviae in poultry in Ethiopia

A survey was conducted into respiratory infectious diseases of poultry on a chicken breeder farm run by the Ethiopian Institute of Agricultural Research (EIAR), located in Debre Zeit, Ethiopia. Oropharyngeal swabs were collected from 117 randomly selected birds, and blood was taken from a subset of 73 of these birds. A combination of serological and molecular methods was used for detection of pathogens. For the first time in Ethiopia, we report the detection of variant infectious bronchitis virus (793B genotype), avian metapneumovirus subtype B and Mycoplasma synoviae in poultry. Mycoplasma gallisepticum was also found to be present; however, infectious laryngotracheitis virus was not detected by PCR. Newcastle disease virus (NDV) was not detected by PCR, but variable levels of anti-NDV HI antibody titres shows possible exposure to virulent strains or poor vaccine take, or both. For the burgeoning-intensive industry in Ethiopia, this study highlights several circulating infectious respiratory pathogens that can impact on poultry welfare and productivity.