Zoonotic disease risk perceptions in the British veterinary profession

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

The epidemiology and ecology of infectious diseases in Ethiopian village chickens and the role of co-infection in infection risk

The scavenging village chicken is important to millions of smallholders in Ethiopia, as in other less-economically developed countries, for its contribution to the economic, nutritional and social well-being of farmers, especially women and children. Infectious diseases are frequently cited as the greatest constraint to village chicken production, and in Ethiopia, most mortality is attributed to seasonal outbreaks of Newcastle disease (ND). This study conducted four cross-sectional surveys over an 18-month period in two geographically distinct regions of Ethiopia, to examine a range of bacterial, viral and parasitic infections in randomly-selected village chickens, and to look at their 6-month survival rate. The two chicken populations of the different regions were found to be different in terms of their population dynamics and phenotypic characteristics, and these may be driven by farmer demands, which are dictated by the local economic and cultural value placed on specific qualities in the chickens. Over the course of the study, no large outbreaks were observed in the eight villages which took part in the study, and only 9 out of 1280 birds (0.7%) were found to be serologically positive for ND. However, even in the absence of large outbreaks, around 20% of the birds in the study were reported to have died of disease within the 6-month follow-up period, and a further 13% lost to predation. Both location and seasonal variation influenced a bird’s fate, as did farmer decisions, such as choosing birds with specific characteristics to sell or eat. Rather than large outbreaks, the rainy season appeared to be associated with increased small-scale losses, and a variety of signs were described, suggesting several pathogens may be involved. No single infection measured at the time of sampling was a good predictor of subsequent death from disease; instead different pathogens appeared to be important in each region, and reduced the probability of survival through a variety of mechanisms. Positive correlations between Pasteurella and Salmonella, and between Marek’s disease and parasitic diseases were identified, but fewer birds than expected were identified with pathogens from both these groups, perhaps suggesting a decreased chance of survival for co-infected birds. Strong seasonal variation in prevalence was not observed for any of the infections in the study, suggesting that seasonal rises in disease mortality are unlikely to be attributable to a single infection, but other factors may play a role, including an increased probability of co-infection. This makes it difficult to prioritise control strategies for individual diseases; instead development programmes may find broad-based strategies, such as improving hygiene and chick management may be more beneficial to minimise the small-scale losses. Programmes also need to be tailored to local needs rather than assuming a blanket strategy will work equally well for all farmers or regions. Any development strategies to control single diseases should consider potential impacts on non-target infections, due to the existence of multiple interactions between pathogens in this system

Guide to chicken health and management in Ethiopia: For farmers and development agents

Biotechnology and Biological Sciences Research Council, United KingdomDepartment for International Development, United Kingdo

Using SNP addresses for Salmonella Typhimurium DT104 in routine veterinary outbreak detection

SNP addresses are a pathogen typing method based on whole-genome sequences (WGSs), assigning groups at seven different levels of genetic similarity. Public health surveillance uses it for several gastro-intestinal infections; this work trialled its use in veterinary surveillance for salmonella outbreak detection. Comparisons were made between temporal and spatio-temporal cluster detection models that either defined cases by their SNP address or by phage type, using historical data sets. Clusters of SNP incidents were effectively detected by both methods, but spatio-temporal models consistently detected these clusters earlier than the corresponding temporal models. Unlike phage type, SNP addresses appeared spatially and temporally limited, which facilitated the differentiation of novel, stable, or expanding clusters in spatio-temporal models. Furthermore, these models flagged spatio-temporal clusters containing only two to three cases at first detection, compared with a median of seven cases in phage-type models. The large number of SNP addresses will require automated methods to implement these detection models routinely. Further work is required to explore how temporal changes and different host species may impact the sensitivity and specificity of cluster detection. In conclusion, given validation with more sequencing data, SNP addresses are likely to be a valuable addition to early warning systems in veterinary surveillance