Veterinary epidemiology: History, roles and perspectives

윤하청,정우석,안효영,조영미,문운경 한국예방수의학회 2013 예방수의학회지 Vol.37 No.2

The concept of veterinary epidemiology had been established in 1960s. It has come a long way during the last 50 decades in interacting with other disciplines. This study describes the initial history of veterinary epidemiology, contribution to the progress of veterinary science, trend of research including surveillance and epidemiological tools, and the perspectives. The epidemiological approach should stay collaborative, interdisciplinary and trans-sectional as it has been developed on the basis of multiple causation theory. The convergence of the One Health and the Ecohealth must be one way for the veterinary epidemiology to go in the near future.

H5N8 Highly Pathogenic Avian Influenza in the Republic of Korea: Epidemiology During the First Wave, from January Through July 2014

윤하청,문운경,정우석,최지다,강영명,안효영,김지혜,유대성,권영진,Woo-Seok Chang,김명수,김도순,김용상,주위석 질병관리본부 2015 Osong Public Health and Research Persptectives Vol.6 No.2

Objectives: This study describes the outbreaks of H5N8 highly pathogenic avian influenza (HPAI) in Korea during the first wave, from January 16, 2014 through July 25, 2014. Its purpose is to provide a better understanding of the epidemiology of H5N8 HPAI. Methods: Information on the outbreak farms and HPAI positive wild birds was provided by the Animal and Plant Quarantine Agency. The epidemiological investigation sheets for the outbreak farms were examined. Results: During the 7-month outbreak period (January-July 2014), H5N8 HPAI was confirmed in 212 poultry farms, 38 specimens from wild birds (stools, birds found dead or captured). Ducks were the most frequently infected poultry species (159 outbreak farms, 75.0%), and poultry in 67 (31.6%) outbreak farms was asymptomatic. Conclusion: As in the previous four H5N1 epidemics of HPAI that occurred in Korea, this epidemic of H5N8 proved to be associated with migratory birds. Poultry farms in Korea can hardly be free from the risk of HPAI introduced via migratory birds. The best way to overcome this geographical factor is to reinforce biosecurity to prevent exposure of farms, related people, and poultry to the pathogen.

Home range differences by habitat type of raccoon dogs Nyctereutes procyonoides (Carnivora: Canidae)

정우성,김달호,윤하청,김희종,강영명,문운경,최지다,박홍식,조해진 국립중앙과학관 2017 Journal of Asia-Pacific Biodiversity Vol.10 No.3

From July 2013 to November 2014, this research was conducted to secure baseline data to find long-term preventive measures against epidemics from the analysis of home range and movement characteristics of raccoon dogs, which are known as carriers of zoonosis. Researchers conducted a follow-up study with 12 raccoon dogs, each attached with a Global Positioning System mobile transmitter. Analysis of home range used the minimum convex polygon (MCP) method and kernel density estimation (KDE) with accumulating data of time-based locations. Except for three animals that showed unique behavior, the researchers analyzed nine animals and calculated their average home range. As a result, average home range was 0.48 ± 0.35 km2 (MCP method), and KDE result analysis was verified as 0.65 ± 0.66 km2 (95%), 0.31 ± 0.35 km2 (75%), and 0.23 ± 0.28 km2 (50%). Based on the MCP method, acted in range of minimum 0.07 km2 and maximum 1.08 km2, and the core habitat, KDE 50% level showed activity range in 0.02 km2 to 0.37 km2. Three individuals of unique behavior were classified into two types. Two individuals moved 10–20 km and settled at a place different from the existing habitat, and one individual kept moving without a regular sphere of influence. Generally, raccoon dogs are not considered to move if they secure their area of influence; animals in urban areas have a wider area of influence than those living in areas with a rich source of food such as forest and agricultural land.

Evaluation on freshness and microbiological quality for eggs collected from grocery stores in Korea

송보라,김영조,윤하청,임종수,서건호,허은정,박현정,위성환,문운경,오선민,문진산 한국예방수의학회 2013 예방수의학회지 Vol.37 No.2

A total of 960 egg samples were collected during each season of spring, summer, fall, and winter between September, 2011 and August, 2012. Thirty eggs each were collected from eight grocery stores located in Hwaseong, Anseong, Incheon, Pocheon, Eumseong, Gunsan, Gumi, and Yangsan with consideration for geographical conditions, scale of markets, and state of washing. When each pH of eggs' yolk and white was examined, the mean pH values of egg yolk and egg white were 6.02~6.37 and 9.07~9.19, respectively. The pH of the egg was affected by seasonal change (P<0.05). Most of the eggs collected from spring and winter were fresh, considering the pH of white and yolk, and the freshness of eggs was lowest for those collected during summer and fall. However, the pH of washed and unwashed white and yolk was not affected by seasonal change (P>0.05). Haugh unit was represented in the order of winter (74.15), spring (70.52), fall (65.90), and summer (60.30). In addition, the total viable counts of egg content showed minor differences according to season, however, egg shells showed differences (P<0.05) according to season. Eggs collected during summer showed the highest total viable count level (mean 3.63±0.54 log cfu/g). In contrast, eggs collected from winter showed the lowest total viable count level (mean 1.57±0.68log cfu/g). Total viable counts of shells from washed eggs from large grocery stores were lower than those of unwashed egg shells from small grocery stores. Coliforms were partly isolated at less than 1.0 log cfu/g from egg contents and egg shells collected during summer. In conclusion, the results of this study indicate that the freshness and microbiological quality of eggs have improved since the introduction of storage conditions (0~15℃) for eggs in 2005.

Spring migration of mallards (Anas platyrhynchos) tracked with wild-trackers in East Asia

강태한,강영명,정우석,문운경,윤하청,최지다,이한수 국립중앙과학관 2016 Journal of Asia-Pacific Biodiversity Vol.9 No.3

Mallard is a dominant waterfowl species wintered in Korea. We researched the mallard spring migration route, stopover sites, and breeding sites. We used cannon nets in Central Korea to catch and attach 10 wild trackers (WT-200). The mallards’ spring departure dates were from the end of March to early April. The spring migration route varied by individual mallards, with most moving through the North Korean east coast. Breeding sites were distributed among the interior of Northeastern China. The average distance to the breeding areas was 1,265 km [standard deviation (SD) = 491 km] and the average days spent from wintering site to breeding site was 25.3 days (SD = 19.2 days). The mallards used several stopover sites when on the spring migration route (average 3.3 ± 2.1, range 2–9). The time spent at the stopover sites was a minimum of 1 day to a maximum of 16 days. Wintering mallards in Korea showed various individual trends regarding spring migration timing, migration route, stopover sites, and usage days.

Prevalence of antibodies against hepatitis E virus in wild boars (Sus scrofa) in Korea

박유리,박지영,강대영,한도현,윤하청,정우석,안동준,여상건,박최규 한국동물위생학회 2016 韓國家畜衛生學會誌 Vol.39 No.4

We determined the nationwide seroprevalence of hepatitis E virus (HEV) infection in the wild boar pop-ulation in Korea. Enzyme-linked immunosorbent assay (ELISA) results showed that 42% of the 528 wild boars that were hunted between 2013 and 2014 were anti-HEV antibody positive. Furthermore, all Korean provinces showed an HEV seroprevalence between 9.8% and 51.1%, suggesting that wild boar HEV infection occurs throughout the country. Importantly, infected wild boar could act as a potential reservoir for HEV and could aid transmission to other animals and humans.

Migration of Grey Heron from the Peter the Great Bay and the Potential Transmission Routes of Avian Influenza

Ivan Tiunov,Igor Katin,이광녕,홍성근,이일섭,윤하청,이은섭,이한수,이시완 국립중앙과학관 2022 Journal of Asia-Pacific Biodiversity Vol.15 No.2

Eight nestlings of Grey Heron were captured in the Peter the Great Bay, Primorskii Territory, Russia and were deployed with trackers supporting GPS and Mobile Phone in May 2017. In total, 35,166 records on the locations of the birds were obtained over the study period until November 18, 2019. The tracking data were available for seven birds in autumn 2017, three birds from spring to autumn 2018, two birds in spring 2019, and only a single bird in autumn 2019. We could trace the migration routes accurately and locate the places for feeding and resting of the Grey Heron during the post-nesting period and seasonal migrations. The direction of the migration of the Grey Herons in autumn was southwest, and it was northeast in spring without exception. With tracking data, we found that there were two main patterns of migration of the Grey Heron: fast and delayed migration. The Grey Heron has been frequently reported to be affected by highly pathogenic avian influenza, and thus, a possibility that infected Grey Heron delivers avian influenza virus in East Asia had been discussed.