돼지 생식기호흡증후군 바이러스의 항체분포 및 역학조사

박최규,장정호,강영배,이창희,류영수,김현수,Park, Choi-kyu,Chang, Chung-ho,Kang, Yung-bae,Lee, Chang-hee,Lyoo, Young-soo,Kim, Hyun-soo 대한수의학회 1999 大韓獸醫學會誌 Vol.39 No.1

A nation wide sero-epidemiological survey of porcine reproductive and respiratory syndrome(PRRS) was carried out to analyze the current status of the PRRS virus infections in the field using the indirect immunofluorescent antibody assay(IFA) with the field isolate PL96-1. Since the first report of the antibody detection to PRRSV in 1993, the prevalence of seropositive pigs has increased dramatically and the data indicate that over 21% of the pigs and around 60% of the farms showed seropositives to the PRRS virus. A slightly higher positive rate was recognized in breeders than fattenings and it might be due to the higher age at the time of testings. No significant regional differences were detected in the sero-epidemiological survey. Higher sero-positive rate in growers indicates that PRRSV infection in the field was common after weaning(around 40 days). However, the number of seropositive pigs were declined in fattening pigs. Sows showed around 26% of sero-positive rate that there is a higher chance of continuous virus circulation in the infected farms. Low rate of sero-positivity in boars(9.8%) implies that there is high demand in proper control measures to prevent virus spreading through breeding procedures such as natural or artificial insemination. Therefore it was concluded that PRRSV infection in domestic swine herds is endemic and the positive rate and economic loses will be increased by spontaneous infections in naive farms.

Porcine circovirus 2 국내 분리주의 유전적 특성

박최규,이경기,김현수,Park, Choi-Gyu,Lee, Kyoung-Ki,Kim, Hyun-Soo 대한수의학회 2004 大韓獸醫學會誌 Vol.44 No.4

In order to obtain the genetic informations of the Korean isolates of porcine circovirus 2 (PCV2), nucleotide sequences of total genome of three isolates and open reading frame 2 (ORF2) of four isolates were determined and compared with those of other reference PCV2 isolates. Nucleotide sequences of 3 isolates showed over 99% homology with those of reference strain (GenBank accession no. AF027217). Point mutations were mainly determined on ORF2 regions but little on ORF1 regions. The patterns of pointmutated sites and nucleotide substitution on ORF2 regions were generally consistent between Korean isolates, and these mutated sites observed in Korean isolates were also relatively similar to those of foreign isolates. Phylogenetic analysis of nucleotide or amino acid sequences showed that there were minor branches consisting of three clusters; cluster of Korea, Canada and America, cluster of Spain and Taiwan, and the last cluster of French and China isolates. These results suggested that Korean PCV2s were probably originated from North America such as Canada or USA. The genetic informations obtained from this study could be useful for the research of diagnosis and pathogenecity of PCV2.

이유자돈 전신소모성증후군 이환 자돈에서의 바이러스성 원인체 검색 및 porcine circovirus 2 분리동정

박최규,김현수,Park, Choi-Kyu,Kim, Hyun-Soo 대한수의학회 2004 大韓獸醫學會誌 Vol.44 No.4

To detect viral agents and isolate porcine circovirus 2 (PCV2), 60 samples of lung and lymph node were collected from 5 to 12 week-old pigs that had showed clinical signs of postweaning multisystemic wasting syndrome (PMWS). Polymerase chain reactions (PCRs) were conducted to identify the viral pathogens including PCV1, PCV2, porcine parvovirus (PPV) and porcine reproductive and respiratory syndrome virus (PRRSV) that have been considered to be the causal agents of PMWS. Among 60 samples, PCV 2 was detected from 57 samples but no PCV 1 was detected. PRRSV and/or PPV were also detected from 27 (47.4%) samples and 1 (1.8%) sample of these 57 PCV 2-positive samples, respectively. Tissue homogenates were inoculated onto PCV-free PK-15 cell monolayers. Seven isolates were confirmed as PCV 2 by multiplex PCR, indirect immunofluorescence assay, and transmissible electron microscopy. These date suggest that PRRSV is a major cofactors causing PMWS in pigs that were infected with PCV2 in Korea.

혈청학적 분석을 통한 돼지 생식기호흡기증후군의 농장단위 감염유형

박최규,윤하정,이창희,정병열,이경기,김현수,Park, Choi-Kyu,Yoon, Ha-Chung,Lee, Chang-Hee,Jung, Byeong-Yeal,Lee, Kyoung-Ki,Kim, Hyun-Soo 대한수의학회 2008 大韓獸醫學會誌 Vol.48 No.1

Porcine reproductive and respiratory syndrome (PRRS) is the most economically important viral infectious disease in pig populations worldwide. This study was conducted to better understand the epidemic and dynamics of PRRS virus (PRRSV) on each farm and to evaluate the risk of PRRSV infection in Korea. Interviews with pig farmers were carried out to obtain PRRS vaccination programmes in 60 pig farms throughout Korea. Blood samples were also collected from the 59 pig farms to investigate outbreak patterns of each farm. Vaccination against PRRS was performed in 16.7% farms for breeding pigs and 8.3% of farms for nursery pigs. According to the seroepidemiological analysis, 56 (94.9%) out of 59 farms were considered to be affected by PRRSV infection. The results revealed that 68.9% of sows tested were seroconverted and interestingly, gilt herds had the highest seropositive rate (73%), suggesting that gilts may play a key role in PRRSV transmission in sow herds. Among the PRRS-affected piglet herds, 33 (55.9%), 14 (23.7%) and 6 (10.2%) farms were initially infected with PRRSV during the weaning, suckling and nursery period, respectively. It seems likely, therefore, that PRRSV infection predominantly occurs around the weaning period in piglet herds. Based on antibody seroprevalence levels in both sow and piglet groups, we were able to classify patterns of PRRSV infection per farm unit into 4 categories; category 1 (stable sow groups and non-infected piglet groups), category 2 (unstable sow groups and non-infected piglet groups), category 3 (stable sow groups and infected piglet groups), and category 4 (unstable sow groups and infected piglet groups). Our data suggested that 43 (72.9%) farms were analysed to belong to category 4, which is considered to be at high-risk for PRRS outbreak. Taken together, our information from this study will provide insight into the establishment of an effective control strategy for PRRS on the field.

RT-PCR for detection of group A, B and C porcine rotaviruses

박최규,류영수,Park, Choi-kyu,Lyoo, Young-soo,Paul, Prem S. The Korean Society of Veterinary Science 1998 大韓獸醫學會誌 Vol.38 No.1

본 연구에서는 돼지 로타바이러스의 혈청형 A, B 및 C를 동시에 진단할 수 있는 RT-PCR 기법을 개발하였다. 각각의 혈청형에 특이적인 primer를 이용하여 RT-PCR 기법으로 분변시료에서 직접 바이러스 동정을 실시한 결과, 23건의 로타바이러스 감염 분변 시료에서 13건이 혈청형 A, 3건이 혈청형 B, 2건이 혈청형 C로 나타나 국내에서도 A, B 및 C형의 돼지 로타바이러스가 공히 발생하고 있음을 확인하였으며, 발생분포는 외국의 예와 유사하였다. 이 RT-PCR기법은 돼지 로타바이러스의 주요 혈청형인 A, B 및 C형의 동시감별진단법으로 이용될 수 있을 것으로 판단된다.

돼지 생식기호흡기증후군 바이러스항체 검색에 있어 간접형광항체법(IFA) 과 효소면역법(ELISA)의 진단효율 비교

박최규,류영수,이창희,정종욱,Park, Choi-kyu,Lyoo, Young-soo,Lee, Chang-hee,Jung, Jong-wook 대한수의학회 1998 大韓獸醫學會誌 Vol.38 No.2

An establishment of effective control measures to PRRSV infection in swine industry depends on a sensitive and specific diagnosis to detect either viral antigen and/or antibodies to PRRSV. Several diagnostic methods are available to detect antibodies against PRRSV, including IPMA, IFA and ELISA tests have been successfully developed. Sensitivity of the indirect immunofluorescent assay in MA-104 cells using Korean field isolate PL96-1 was superior to that of VR-2332 and field isolate PL96-2. Sensitivity and specificity of the IFA test with PL96-1 were comparable to those of commercial ELISA test kit but ELISA test was more sensitive for the detection of declining antibodies to PRRSV in finishing pigs. In this study we concluded that IFA and ELISA test could be utilized to detect antibodies to PRRSV and the results generated from these two tests were comparable and there were no significant difference between these two tests.

2002년 한국에서 발생한 돼지콜레라의 역학적 특성

박최규,송재영,위성환,이은섭,윤하정,문운경,최은진,남향미,Park, Choi-Kyu,Song, Jae-Young,Wee, Sung-Hwan,Lee, Eune-Sub,Yoon, Hachung,Moon, Oun-Kyeong,Choi, Eun-Jin,Nam, Hyang-Mi 대한수의학회 2006 大韓獸醫學會誌 Vol.46 No.2

This paper described the epidemiological characteristics of 2002 outbreak of classical swine fever (CSF) in Korea. A total of thirteen CSF-infected farms could be classified into two clusters according to the location and time of outbreak. Two farms located in the same county of Gangwon province and 11 farms located in several different districts of Incheon metropolitan/Gyeonggi province were identified as CSF-infected from April 16 to 30 and from October 7 to December 21 in 2002, respectively. As the result of epidemiological analysis, the two clusters of outbreaks were turned out to be independent epidemics which had different sources of virus introduction. Three farms were found to have been infected primarily; one located in Cheolwon county of Gangwon province and two located in Kangwha county of Incheon metropolitan area. The most likely factors of virus introduction into these primary infected farms were considered to be direct or indirect contact by foreign workers and/or owners of the infected farms who had come back from traveling in China before outbreaks. This was supported by the genetic typing of CSF viruses isolated from the pigs of infected farms. All the virus isolates of 2002 outbreak were found to be genetic type 2, whereas the viruses isolated before 2000 were type 3 and the reference strains, such as attenuated live vaccine virus (LOM strain) and high virulent challenge virus (ALD strain), were type 1. Accordingly, we concluded that the 2002 CSF outbreak must have been caused by a newly introduced virus from overseas and the type 3 virus must have been eradicated after the last outbreak of 1999 by the national CSF eradication campaign which were implemented since 1996. Based on the combined analysis of epidemiological data and genetic typing, the transmission routes of classical swine fever virus were found to be the movement of vehicles (60%) and persons (10%), neighbourhood spread (20%) and unknown (10%). It is expected that the analyzed data and findings of classical swine fever outbreak epidemic could be very useful to establish the disease control and eradication program for the country in the future.

2003년 한국의 돼지콜레라 전국적 확산에 대한 기술역학

박최규,이은섭,윤하정,위성환,송재영,문운경,최은진,김현수,이주호,안수환,Park, Choi-Kyu,Lee, Eune-Sub,Yoon, Hachung,Wee, Sung-Hwan,Song, Jae-Young,Moon, Oun-Kyeong,Choi, Eun-Jin,Kim, Hyun-Soo,Lee, Joo-Ho,An, Su-Hwan 대한수의학회 2006 大韓獸醫學會誌 Vol.46 No.3

In March 2003, classical swine fever (CSF) infection was reported in a piggery located at Iksan city, Jeollabuk-do in Korea. Subsequently, a total of 72 infected farms were confirmed between March and December, 2003. Based on epidemiological investigation of the earlier confirmed infected farms, the source of infection was shown to be from a breeding farm. Targeted surveillance of 82 piggeries that had acquired pigs from this breeding farm showed 44 piggeries were infected with CSF virus. CSF virus was introduced into this breeding farm by movement of selected breeder pigs from its 12 contracted farms which were located in areas that had been affected by CSF epidemic in late 2002. CSF had then spread through out the country mainly by direct transmission through the sale and movement of pigs from this breeding farm. Consequently, 47 (62%) among 72 CSF affected farms were associated, directly and indirectly, with this breeding farm. This study showed that inadequate control for breeding farms and transport restriction in CSF outbreak areas resulted in the nationwide spread of CSF and the failure of the eradication campaign that has been underway for several years by the Korean animal hygiene authority as well as the fanners. Improvements of control policy through further research of the 2003 CSF epidemic will be needed to reestablish the Korean CSF eradication program in the future.

우리나라 양돈장의 예방 접종 실태 조사

박최규 ( Choi Kyu Park ),정병열 ( Byeong Yeal Jung ),윤하정 ( Ha Chung Yoon ),이창희 ( Chang Hee Lee ),김현수 ( Hyun Soo Kim ) 한국수의공중보건학회 2007 예방수의학회지 Vol.31 No.3

번식돈에서의 돼지 생식기 호흡기증 바이러스 항체 분포 조사

박최규 ( Choi Kyu Park ),김현수 ( Hyun Soo Kim ) 한국가축위생학회 2004 韓國家畜衛生學會誌 Vol.27 No.1

Total 2,451 sera collected from pig farms nationwide were tested for the detection of porcine reproductive and respiratory syndrome(PRRS) virus antibodies. The results were analyzed between different geographic regions, types of breeding pigs, and different years. The overall seroprevalence of PRRS virus antibodies for 3 years was 32.4%(705/2,451). The seroprevalence of PRRS virus antibodies in years 2000, 2001, 2002, and 2004 was 33.4% (284/850), 38.6%(291/754), 33.3%(155/466), and 17.1%(65/381), respectively. The seropevalence of PRRS virus antibody in sow in years 2000, 2001, 2002 and 2003 was 31.7%, 28.4%, 29.6%, and 13.4%, respectively. The seropevalence of PRRS virus antibody in gilts in years 2000, 2001, 2002 and 2003 was 36.6%, 67.4%, 54.7%, and 33.9%, respectively. The seropevalence of PRRS virus antibody in boars in years 2000, 2001 and 2003 was 45.7%, 36.4%, and 100%, respectively. No boar serum sample was submitted for the diagnosis of PRRS virus antibody in the year 2000. High seroprevalence of the PRRS virus antibody in sow, gilts and boars indicates that the infected breeding pigs are the major source of the PRRS virus infection, and also play an important role in spreading the PRRS virus between fan mates or herds.