Emergence of highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) in medium-scale swine farms in southeastern Cambodia.

Since 2006, reports from China and Viet Nam have alerted of an emergent highly pathogenic variant of porcine reproductive and respiratory syndrome virus (HP-PRRSV) in that region. The frequent occurrence of outbreaks in these countries puts Cambodian pig farms at high risk of infection, but no study had been conducted to investigate the presence of HP-PRRS in Cambodian farms. We investigated the presence of HP-PRRS in medium-scale (semi-commercial) swine farms in the Cambodian southeastern region. Specifically, one province bordering Viet Nam (Takeo) was selected due to the concentration of most semi-commercial farms in that province. A cross-sectional study was carried out, between July and September 2010 to assess whether the prevalence of infection in these farms was indicative of recent spread of PPRSV and to identify risk factors for infection. The number of farms to be sampled was established using methods for Lot Quality Assurance Surveys (LQAS), in order to achieve a pre-established ability to discriminate between two different prevalence settings. The target population comprised all semi-commercial farms in Takeo province from which a random sample of 35 farms was selected. Selected farms were visited and questionnaires administered to gather information on farm characteristics and husbandry practices. Blood samples from individual pigs were collected in each of the study farms and tested for PRRSV, along with a number of other swine respiratory pathogens in order to investigate potential interactions. Our results showed that the virus was already present in Takeo semi-commercial pig population (LQAS herd prevalence ≥85%) at the time of sampling. The presence of sows in the farm and farm density were significantly associated (P<0.05) with the introduction and the presence of PRRS - but this was an unadjusted association as small sample size precluded multivariate analysis. Spatiotemporal description of the supposed pattern of infection revealed that the 1st farms infected were closely located to major national and provincial roads, connecting the Cambodian capital Phnom Penh to Viet Nam.

Knowledge, attitudes and practices of Cambodian swine producers in relation to porcine reproductive and respiratory syndrome (PRRS).

Porcine reproductive and respiratory syndrome (PRRS) was first detected in Cambodia in 2010. The disease was responsible for high morbidity and high mortality in adult pigs and the outbreak had a costly impact on those farmers affected. The aim of this study was to generate a better understanding of Cambodian swine producers' behaviour, in relation to PRRS and its control, in areas that have previously been affected by the disease. A survey of the knowledge, attitude and practices (KAPs) of pig owners with regard to PRRS was conducted in semi-commercial and backyard farms in Takeo province in southeast Cambodia. The survey was designed to assess knowledge of PRRS disease and its transmission, farmers' attitudes and practices related to preventive and control measures, knowledge on vaccination and perception towards local veterinary authority activities. Descriptive statistics were used to summarise qualitative data, while multivariate regression analyses were used to assess the association between selected outcomes and a number of hypothetical predictors. When presented with clinical signs typical of PRRS, most farmers identified an infectious disease as the most likely explanation for the listed clinical conditions. Farmers were also confident in recognising direct contact between pigs as one of the main ways of disease transmission; however, other viral transmission patterns typical of PRRS were mostly unknown or ignored. In general, male farmers and farmers with a higher level of education were more likely to have a better knowledge of transmission routes between pigs. In terms of attitude towards control measures, vaccination and disinfection were perceived as the most effective control practices. Farmers with a better knowledge of vaccine protocols were more likely to find vaccination effective. Village animal health workers (VAHWs) were generally in contact more with backyard farmers, while semi-commercial farmers were more prone to treat pigs themselves, raising the issue of easy and uncontrolled access to medication and vaccination. In general, farmers had a positive attitude towards local veterinarians, and lack of contact between farmers and the veterinary authority was associated more with logistic constraints than with farmers' mistrust towards the authority.