Swine influenza is a respiratory infectious disease in pigs caused by Orthomyxoviridae influenza virus A. As a multihost pathogen, the virus can infect humans, birds, and pigs and has pandemic potential due to rapid mutation rate. This study investigated the seroprevalence of influenza A antibodies in pigs in Chungbuk Province to overview its temporal and spatial distribution. From March to November 2021, blood samples collected for swine fever and foot-and-mouth disease antibody tests from swine farms located in Cheongju, Jincheon, Jeungpyeong, and Goesan within the jurisdiction of the Chungbuk Animal Health Laboratory were used. Blood samples from both sows and growing pigs were collected. Additionally, three farms participating in the Expendable Disease Guidance Support Project were chosen to investigate the seroprevalence status by parity of sows and age of piglets. A total of 468 sows and 1,519 growing-finishing pigs were employed in this study. The results showed that Jincheon had the highest seropositivity rate, suggesting that more effort should be made in biosecurity to prevent mechanical transmission, given the close proximity of farms. The analysis of antibody levels in farms targeted by the Expendable Disease Guidance Support Project could suggest that once the virus enters a farm, it spreads throughout the entire pig population regardless of age. Farms that were positive in the first half of the year remained positive in 86% of cases in the second half, suggesting continuous infection within the farm unless depopulation or all-in-all-out practices are implemented. Moreover, 67% of farms that were negative in the first half remained negative in the second half, and farms managed by the same person showed identical antibody change patterns, indicating that the swine influenza virus can be transmitted by humans or vehicles. The results highlight the need for further analysis of biosecurity systems and geographical risk factors.

심장사상충은 개의 폐동맥과 우심실에 기생하면서 혈액순환 장애와 심기능부전을 일으 키는인수공통기생충으로 최근 반려동물과 함께하는 인구수가 증가함에 따라 심장사상충 감염에 대한 인식도 증가하고 있다. 그래서 이 연구는 도시 지역인 광주지역에서 사육되 는 7개 품종 97마리에 대한 심장사상충의 감염률을 항원검사법을 이용하여 조사하였다. 전체 감염률은 총 97마리 중 2마리가 감염되어 2.1%이었다. 사육환경에 따른 감염률은 단독주택 사육환경이 7.1%(1/14마리), 아파트 사육환경이 1.2%(1/83마리)로 단독주택 사육환경에서 높았으며, 성별에 따른 감염률은 수컷이 3.6%(2/55마리), 암컷이 0.0%(0/42마리)로 수컷에서 높았다. 또한 연령에 따른 감염률은 5세 이상에서 4.9%(2/41마리)이었고 4세 이하에서 감염견은 검출되지 않았다. 이 연구를 통해 심장사 상충 감염률은 단독주택 사육환경, 수컷 그리고 노령견에서 높다는 것을 확인하였다.

Rabies is a zoonotic disease that is caused by rabies virus and transmitted only in mammals. Domestic dogs are the most common reservoir of the virus, which is associated with more than 99% human deaths caused by dog-mediated rabies in the world. Rabies is one of the most fatal diseases, but it is fully preventable in animals by vaccination. Serological test of rabies virus antibody for samples collected from dogs and cats in Seoul during 2017–2019 was carried out in this study. To investigate antibody seroprevalence of rabies virus for dogs and cats, 2,769 serum samples were taken from 2,408 dogs and 361 cats in various regions of Seoul during 2017– 2019. Antibodies to rabies virus were detected by an indirect ELISA. Of 2,769 tested animal sera, 934 (33.7%) were positive; 886 (36.8%) of 2408 dogs and 48 (13.3%) of 361 cats. Of 990 companion animals, 547 (55.3%) was positive and 387 (21.8%) of 1779 stray animals was positive. These results indicate that antibody seroprevalence to rabies virus is still not enough to prevent rabies and rabies vaccination is required to enhance the antibody seroprevalence for rabies. To improve the situation, much public awareness and policy is needed to prevent the rabies. In addition, reducing stray animals and keeping companion animals from contact with wild animals are indispensable for the prevention of rabies.

Influenza A virus (IAV) causes respiratory disease in birds and mammals, including pigs and humans. Infection by IAV in pigs increases not only economic losses in the swine industry but also the emergence of novel IAV variants via gene reassortment, which is important due to the susceptibility of both birds and humans to IAV. This study provides serological data obtained during a study to detect IAV infections in pigs in the Republic of Korea during 2018 and 2019. A total of 1,559 samples were collected from 74 domestic pig farms. Hemagglutination inhibition (HI) assays were performed using the A/Swine/Korea/25-13(H1N1), A/Swine/Korea/E102 (H1N2), and A/Swine/Korea/Cy10/2007 (H3N2) viruses as antigens. The HI assay results showed that 266 of the 1,559 samples were seropositive (17.0%). Among these, H1N1, H1N2, and H3N2 comprised 7.3% (114), 6.0% (93), and 8.8% (137) of the 1,559 samples, respectively. Co-infections of H1N1/H1N2, H1N1/H3N2, H1N2/H3N2 and H1N1/H1N2/H3N2 were observed in 2.1% (31), 1.5% (23), 1.5% (24), and 0.8% (13) of the 1,559 samples, respectively. Interestingly, IAV infections were detected in all nine provinces of the country.

Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis. This study was conducted to clarify the seroprevalence of BLV in the Republic of Korea. Blood samples were obtained from Korean native cattle farms in all provinces of South Korea except Jeju. A commercial indirect enzyme-linked immunosorbent assay with 4,498 samples to detect antibodies against BLV was conducted. The results revealed that the prevalence of BLV was dependent upon age, with increasing prevalence among cattle occurring until they were 5 years old. The highest seroprevalence in cattle was observed in Chungnam (29.6%) and the lowest was observed in Jeonnam (2.6%). The mean overall prevalence for BLV antibodies in the survey was 10.2%, indicating that BLV is widespread nationwide.

This study was performed to estimate the seroprevalence of PRRSV in breeding farms in Jeju 2008 using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The tested sera were randomly collected from a total of 1,947 sera from 9 breeding farms unvaccinated in Jeju. As a result, all breeding farms were seropositive for PRRSV. Seven hundred-eighty six of 1,947 sera (40.4%) were positive for PRRSV. Seropositve rate of PRRSV infection in 9 farms showed various levels: 1%, 8.9%, 9.1%, 43%, 46.9%, 48.2%, 51.6%, 60.9%, 85.5%, respectively. The results confirmed that PRRSV infection has been prevailing in breeding farms in Jeju. Also, these results must be taken into a consideration in strategy establishment for the control and eradication of PRRS.

Porcine reproductive and respiratory syndrome (PRRS) virus causes not only breeding disorder such as abortion, stillbirth and premature birth to pregnant sows but economic damage like high estrous return and low delivery rate. The presented study was conducted to confirm seroprevalence of PRRS in Jeju herds. PRRS positive rate was examined with pig serum from hog farms located in Jeju. Serum samples were extracted from the 11 of sow farms and 10 of hog farms, The groups were divided into 20, 40, 60, 80, 100 and older than 120 days of age and pregnant sows in hog farms. Anti-PRRSV antibody titers in sera were analyzed by ELISA. All the breeding farms and hog farms (10/10) showed PRRS positive except one breeding farm (1/11). Serological patterns determined by ELISA did not show any difference regardless of whether pigs were vaccinated or not. Nevertheless, the farms unvaccinated pigs displayed low productivity in terms of piglet loss rate and prolonged period of shipment. Therefore, vaccination against PRRSV appears to be a crucial factor in sanitary management of hog farms. Taken together, since PRRSV was spread widely in Jeju already, stabilization of sows by PRRS vaccination after adapting PRRSV free sow by all-in-all-out method in farms is recommended for the control strategy for PRRS.