Identification of Brucella spp. in feral swine (Sus scrofa) at abattoirs in Texas, USA

Abstract

Various tissues, nasal swabs, urine and blood samples were collected from 376 feral swine at two federally inspected abattoirs in Texas during six separate sampling periods in 2015. Samples were tested for Brucella spp. by culture and serology. Brucella spp. were cultured from 13.0% of feral swine, and antibodies were detected in 9.8%. Only 32.7% of culture-positive feral swine were also antibody positive, and 43.2% of antibody-positive feral swine were culture positive. Approximately, the same number of males (14.0%) and females (12.1%) were culture positive, and slightly more males (10.5%) than females (8.7%) were antibody positive. Our results indicate that serology likely underestimates the prevalence of feral swine infected, and that those who come in contact with feral swine should be aware of the symptoms of infection with Brucella spp. to ensure prompt treatment.

Field evaluation of low-dose warfarin baits to control wild pigs (Sus scrofa) in North Texas

“…Additionally, wild pigs carry numerous diseases, with meat processed in commercial plants in Texas having been found positive for multiple disease pathogens, including influenza A, Leptospira , Trichinella , Toxoplasma , and Brucella spp. [ 12 , 13 ]. These authors indicated 48.9% of tested pigs were positive for antibodies of one or more serovars of Leptospira spp.…”

Zoonotic pathogens from feral swine that pose a significant threat to public health

“…This side‐by‐side testing found that only 52% of sera from culture positive animals were antibody positive, indicating that feral swine are carriers of B. suis and that serological results are a suboptimal indicator of infection. These findings were echoed by Pedersen, Bauer, et al () when evaluating B. suis isolation and antibody presence in feral swine in two abattoirs in Texas. The B. suis organism was detected in 13% of feral swine sampled, while only 9.8% of animals were seropositive, again demonstrating that serology underestimates the true prevalence of B. suis infection in feral swine.…”

“…Further work with feral swine in the United States identified B. suis culture‐positive animals as a result of routine culling activities (Pedersen et al., ) as well as in feral swine slaughter establishments (Pedersen, Bauer, et al., ). Apparently healthy animals from 16 counties in eight states were culled for collection and evaluation of lymph nodes and blood for bacteria and antibody presence, respectively (Pedersen et al., ).…”

“…In several of these cases (Franco‐Paredes et al., ; Simoes & Justino, ), the infected individual reported cutting themselves while processing the feral swine carcasses; however, in other instances lacerations were not reported. Testing of samples from feral swine in federally inspected slaughter facilities in Texas showed that there was not one tissue type that was consistently positive for B. suis , suggesting that the bacteria was not localized to a specific tissue or body region (Pedersen, Bauer, et al., ). Cumulatively, these findings indicate that close contact with carcasses or secretions from feral swine pose a risk for the contraction of B. suis and caution should be taken when exposed to these animals.…”

“…Because tags are not issued for feral swine hunting, there is no information available relative to the number of hunters or the number of feral swine harvested annually in the state. Furthermore, commercial abattoirs have begun processing feral swine (Pedersen, Bauer, et al., ), primarily as a result of an increased demand for feral swine meat. Both of these practices increase interactions between humans and feral swine, which could facilitate disease transmission.…”