Surveillance for respiratory and diarrheal pathogens at the human-pig interface in Sarawak, Malaysia

Abstract

BackgroundThe large livestock operations and dense human population of Southeast Asia are considered a hot-spot for emerging viruses.ObjectivesTo determine if the pathogens adenovirus (ADV), coronavirus (CoV), encephalomyocarditis virus (EMCV), enterovirus (EV), influenza A-D (IAV, IBV, ICV, and IDV), porcine circovirus 2 (PCV2), and porcine rotaviruses A and C (RVA and RVC), are aerosolized at the animal-interface, and if humans working in these environments are carrying these viruses in their nasal airways.StudyThis cross-sectional study took place in Sarawak, Malaysia among 11 pig farms, 2 abattoirs, and 3 animal markets in June and July of 2017. Pig feces, pig oral secretions, bioaerosols, and worker nasal wash samples were collected and analyzed via rPCR and rRT-PCR for respiratory and diarrheal viruses.ResultsIn all, 55 pig fecal, 49 pig oral or water, 45 bioaerosol, and 78 worker nasal wash samples were collected across 16 sites. PCV2 was detected in 21 pig fecal, 43 pig oral or water, 3 bioaerosol, and 4 worker nasal wash samples. In addition, one or more bioaerosol or pig samples were positive for EV, IAV, and RVC, and one or more worker samples were positive for ADV, CoV, IBV, and IDV.ConclusionsThis study demonstrates that nucleic acids from a number of targeted viruses were present in pig oral secretions and pig fecal samples, and that several viruses were detected in bioaerosol samples or in the nasal passages of humans with occupational exposure to pigs. These results demonstrate the need for future research in strengthening viral surveillance at the human-animal interface, specifically through expanded bioaerosol sampling efforts and a seroepidemiological study of individuals with exposure to pigs in this region for PCV2 infection.

Reservoirs of Porcine Circoviruses: A Mini Review

“…Another study also identified the existence of PCV2 in bioaerosol samples from pig farms and abattoirs. In addition, PCV2 was detected in nasal washes of workers (4/78) from pig farms (65). This revealed that PCV2 was a potential airborne virus.…”

“…Interestingly, scientists from Northern Ireland, the United States, and Germany could not detect antibodies or antigens of PCV2 in human samples (56)(57)(58)(59). However, in other studies, antibody of PCV1 or antigen of PCV2 was detected in human sera, digestive tract samples and respiratory tract samples (60)(61)(62)(63)(64)(65). Although there is serological and molecular proof of PCV presence in humans, the detection rate is very low.…”

Bioaerosol Sampling for Respiratory Viruses in Singapore’s Mass Rapid Transit Network

“…DNA/RNA was extracted from 0.5 mL of each aerosol sample and negative control sample solution using the QIAamp Viral RNA kit and QIAamp DNA Blood kit (Qiagen) following the manufacturer's instructions. Using previously validated probe-based molecular assays [38][39][40][41][42] adapted to the Duke-NUS Laboratory of One Health Research, extracted RNA was tested for the presence/absence of influenza A and B viruses, enteroviruses, coronaviruses, and RSV subtypes A and B using superscript III One-step real-time RT-PCR with Platinum Taq Polymerase. RSV-A and RSV-B assays were not adapted to our laboratory during the time of sampling and therefore were performed 3 months after the last aerosol sample was collected.…”

Recent Research on Occupational Animal Exposures and Health Risks: A Narrative Review

“…Additionally, high concordance was noted between A(H1N1)pdm09-like H1N1 viruses isolated from workers with ILI and IAV circulating among swine, indicating species crossover. A second study, led by Borkenhagen et al identified influenza B and influenza D viruses in swine worker nasal passages during a surveillance study in Malaysia [44]. The authors also recovered porcine circovirus 2 in worker nasal specimen as well as in pig specimen, indicating zoonotic concern associated with this viral pathogen of growing concern in Asia.…”