No abstract

Pig farmers and veterinarians in contact with livestock in The Netherlands have a higher risk of methicillin-resistant Staphylococcus aureus (MRSA) carriage than the general population. The objective of this study was to investigate whether this is also true for other professionals in contact with pigs in an international setting. A convenience sample of 272 participants at an international conference on pig health in Denmark was screened for MRSA carriage using combined nose/throat swabs and were asked to complete a questionnaire concerning animal contacts, exposure to known MRSA risk-factors, and the protective measures taken when entering pig farms. In total, 34 (12.5%) participants from nine countries carried MRSA. Thirty-one of these isolates were non-typeable by pulsed-field gel electrophoresis following SmaI digestion of chromosomal DNA. All of the non-typeable isolates belonged to spa types (t011, t034, t108, t571, t567 and t899) that correspond to multilocus sequence type 398. All of the above-mentioned spa types, with the exception of t899, have been isolated previously from either Dutch pigs, pig farmers and/or veterinarians. Protective measures, e.g., masks, gowns and gloves, did not protect against MRSA acquisition. Transmission of MRSA from pigs to staff tending to these animals appears to be an international problem, creating a new reservoir for community-acquired MRSA (CA-MRSA) in humans in Europe, and possibly worldwide. The rise of a new zoonotic source of MRSA could have a severe impact on the epidemiology of CA-MRSA, and may have consequences for the control of MRSA, especially in those countries that maintain a low prevalence by means of search-and-destroy policies.

The economic losses due to porcine reproductive and respiratory syndrome virus (PRRSv) outbreaks are reported in the literature to be substantially high, but recent figures are not available. The aim of this study was to quantify the economic effects of epidemic PRRSv outbreaks in Dutch sow herds. Nine sow herds were selected based on a confirmed PRRSv outbreak within those populations. The economic impact during the first 18 weeks after the outbreak was estimated by comparing the overall costs between pre- and postoutbreak periods, using different factors (production data, medication, diagnostics, labour, etc.). An outbreak of PRRSv resulted in a reduced number of sold pigs per sow of 1.7. The economic loss varied between €59 and €379 for one sow per 18-week period outbreak. The mean loss per sow per outbreak was €126. The costs after the outbreak varied significantly from €3 to 160 per sow, due to the different methods used by farmers to tackle PRRSv outbreaks. The calculated costs in this study correlate with the costs of the initial outbreak in The Netherlands of 98 per sow.

Despite a strict control program for methicillin-resistant Staphylococcus aureus (MRSA) in human medicine in the Netherlands, MRSA was cultured from exudative epidermitis lesions of 4 piglets on a breeding farm, 20 pigs on a supplier farm, and 2 workers on these farms. The MRSA strains were indistinguishable, suggesting direct transmission.

No abstract

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the Netherlands, at 1.0%, is among the lowest in Europe. In 2004, a relationship between pig farming and a high risk for MRSA carriage was found. To investigate if those in professional contact with livestock are at higher risk for MRSA carriage, we screened 80 veterinary students and 99 veterinarians and questioned them about animal contacts and known MRSA risk factors. Of these, 27 students who did not have livestock contact were excluded from further analysis. We found 7 carriers of MRSA, a prevalence of 4.6%, which is similar to that found in patients who had previously been treated at foreign hospitals. A correlation of MRSA carriage with a specific animal group could not be established. To preserve the low prevalence of MRSA in the Netherlands, persons involved in the care of livestock should be isolated and screened on admission to the hospital.

No abstract

SUMMARYThe objective of this study was to investigate the dynamics of PRRSV infection and to quantify transmission within a breeding herd, and its impact on herd performance. For this purpose a longitudinal study was performed in a closed breeding herd of 115 sows. Statistical methods and Monte Carlo simulations based on stochastic SIR models were used to analyse the observational data. Moreover, a case-control study was performed to determine whether seroconversion of sows during gestation was associated with aberrant litters. The transmission parameter R was estimated to be 3n0 (95 % confidence interval 1n5-6n0) for the model version based on the most plausible assumptions that the infectious period lasts 56 days and no lifelong immunity exists after infection. Based on simulations using a breeding herd of equal size the average time-to-extinction was estimated to be 6 years ; using a herd of twice the size, it was 80 years. Furthermore, in contrast to the epidemic phase of the disease, the endemic phase was not detrimental to herd performance.