Early mycoplasma hyopneumoniae infections in European suckling pigs in herds with respiratory problems: detection rate and risk factors

The present study aimed at estimating the detection rate of M. hyopneumoniae in 3-week-old pigs in different European countries and to identify possible risk factors. Nasal swabs from suckling pigs in 52 farms were collected for nested PCR analysis. Potential risk factors for respiratory disease were analysed with a multivariable logistic regression model. The average percentage of positive piglets was 10.7% (95% confidence interval, CI 7.4-14.2); at least one pig tested positive in 68% of herds. In 32% of the herds, more than 10% of piglets tested positive. Herds that vaccinated sows against swine influenza virus (SIV) had a significantly higher risk of a piglet being positive for M. hyopneumoniae (OR 3.12; 95% CI 1.43-6.83). The higher risk in case of SIV vaccination is difficult to explain, but may be due to the fact that pig herds with respiratory symptoms are more likely to be vaccinated against SIV, overlooking the possible influence of other respiratory pathogens such as M. hyopneumoniae. The present findings show that M. hyopneumoniae is widespread in 3-week-old piglets across different European countries

Impact of temperature, feeding preference and vaccination on Schmallenberg virus transmission in Scotland

First identified in 2011, Schmallenberg virus (SBV) is principally transmitted by Culicoides midges and affects ruminants. Clinical presentation is typified by foetal abnormalities, but despite very high infection rates, relatively few animals present with clinical signs. In this paper we further develop a previously published stochastic mathematical model of SBV spread to investigate the optimal deployment of a vaccine for SBV in Scotland, a country that has experienced only sporadic and isolated cases of SBV.We consider the use of the vaccine under different temperatures and explore the effects of a vector preference for feeding on cattle. We demonstrate that vaccine impact is optimised by targeting it at the high risk areas in the south of Scotland, or vaccinating only cattle. At higher than average temperatures, and hence increased transmission potential, the relative impact of vaccination is considerably enhanced. Vaccine impact is also enhanced if vectors feed preferentially on cattle. These findings are of considerable importance when planning control strategies for SBV and also have important implications for management of other arboviruses such as Bluetongue virus. Environmental determinants and feeding preferences should be researched further to inform development of effective control strategies