Compared to the general population, veterinarians are more predisposed to acquiring zoonotic infections due to their intensive animal contact (Baker & Gray, 2009; Taylor, Latham, & Woolhouse, 2001). In particular, swine populations are a potential reservoir for zoonotic pathogens and helminths (worms), such as hepatitis E virus (HEV), methicillin-resistant Staphylococcus aureus (MRSA), Leptospira spp . and Ascaris suum (A. suum). Transmission usually occurs through consumption of raw meat (HEV, A. suum), contact with eggs in the environment(A. suum), or contact with secretions from infected animals(Leptospira spp.). However, physical contact with colonized animals or inhalation of contaminated dust (MRSA) can also lead to infections.
In this study, the prevalence of infections with HEV, Leptospira spp . and A. suum as well as nasal MRSA colonization in Austrian practicing veterinarians in the context of occupational exposure of pigs, was investigated. 261 participants from the three largest Austrian veterinary science conferences completed a questionnaire in 2017 about the intensity of pig contact and the use of gloves or face masks. A main distinction was made between large animal veterinarians with frequent (>3 pig visits/week) and infrequent pig contact (<3 pig visits/week). Other behavioral patterns such as hunting, dietary behavior, travel behavior, and disease history and medical treatments were collected. In addition, blood samples from participants were analyzed for IgG antibodies to HEV, Leptospira spp. and A. suum, and nasal swabs were cultured for MRSA. Antibody detection using different methodologies provided information about chronic or past infections of the participants. Via ELISA with a test sensitivity of 100% and specificity of 86%, IgG antibody levels to HEV were determined (Al-Sadeq, Majdalawieh, Mesleh, Abdalle, & Nasrallah, 2018). Antibodies against A. suum were detected by immunoblots, and infection with Leptospira spp . was detected by microscopic agglutination test. Veterinarians with frequent pig contact showed a 1.9 [95% CI: 1-3.4] and 1.5 [95% CI: 1.0-2.3] higher risk of HEV and A. suum infections, respectively, compared to veterinarians with infrequent pig contact and were also 4.8 times [95% CI: 2.5; 9.3] more likely to be nasally colonized with MRSA.The determined prevalence of antibodies to HEV of 21% [95% CI: 15.8-25.7] in all veterinarians was higher compared to previous studies of blood donors and soldiers (Fischer et al., 2015; Lagler et al., 2014). The cumulative risk associated with increasing years of work may account for the increased rate of HEV infection in veterinarians older than 55 years.
Only three veterinarians with infrequent contact with pigs tested positive for antibodies to Leptospira spp. whereas 23% were identified in hunters and professional soldiers. This could be explained due to more frequent unprotected contact with animal secretions or contaminated water (Deutz, 2007; Poeppl et al., 2013).
Surprisingly, 44% [95% CI: 37.7-50.2] of all veterinarians tested positive for A. suum, whereas previous studies showed only 21.9% (Nowotny et al., 1997). Increased consumption of vegetables and fruits due to the trend toward healthier diets may have contributed to this. This study also identified older age as a distinct risk factor.
A prevalence of 13% [95% CI: 9.3-17.6] was found for nasal MRSA colonization among practicing veterinarians, which was associated with the number of weekly visits (>3 visits/week). However, in case of prevention by gloves, occupational pig contact was no longer decisive for MRSA as well as for A. suum. The established protective effect of a face mask (van Cleef et al.,2015) could not be confirmed in this study.
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