부분예산분석을 이용한 오제스키병 발생 농가의 경제적 손실 추정

박선일,박최규,문운경,윤하정,이병용,이상진,Pak, Son-Il,Park, Choi-Kyu,Moon, Oun-Kyong,Yoon, Hachung,Lee, Byeong-Yong,Lee, Sang-Jin 대한수의학회 2009 大韓獸醫學會誌 Vol.49 No.4

Aujeszky's disease (AD) is a respiratory, infectious viral illness associated with high mortality, especially in neonatal piglets and has frequently been considered an economically important disease in many endemic countries. Although AD is still occurring in a geographically defined region in Korea, little attention has been paid to the economics of AD. In this study, partial budget technique was used to develop a simulation model to measure financial losses following the disease epidemic in a swine operation utilizing stochastic or deterministic parameters from the literatures and the index case herd of AD occurred in 2005, where available and applicable. For the infected case herd with a 12500-pig, the total economic loss for this operation was estimated to be about 199 million Korean won (95% confidence interval [CI] 148,645,000-250,741,000). Given net loss due to death of a pig at sow level was 119,000 won, total loss for the case herd with 1200 sows accounted for 143 million won (95% CI 92,599,000-193,729,000). The net loss of the death of one pig at growing and fattening level resulted in loss of 46,000 won (95% CI 40,000-53,000) and 126,000 won (95% CI 122,000-131,000), respectively. Taking into account for the number of pigs raised in the case herd, total loss amounted to 8 million won (95% CI 7,167,000-9,347,000) and 12 million won (95% CI 11,959,000-12,891,000), for growers and fatteners, respectively, assuming 63% of saved feed intake when a pig dies halfway through the respective period. Under the model's assumptions, suckling pig mortality was the major factors of loss in estimating the economic consequences (approximately 71.8% of the total loss). The high economic losses of a herd infected with AD suggest that the effective and region-specific control measures should be implemented in disease endemic foci.

추백리-가금티푸스의 혈청학적 모니터링 계획수립을 위한 표본크기

박선일,박최규,Pak, Son-Il,Park, Choi-Kyu 대한수의학회 2008 大韓獸醫學會誌 Vol.48 No.4

The objective of this study was to determine appropriate sample size that simulated different assumptions for diagnostic test characteristics and true prevalences when designing serological surveillance plan for pullorum disease and fowl typhoid in domestic poultry production. The number of flocks and total number of chickens to be sampled was obtained to provide 95% confidence of detecting at least one infected flock, taking imperfect diagnostic tests into account. Due to lack of reliable data, within infected flock prevalence (WFP) was assumed to follow minimum 1%, most likely 5% and maximum 9% and true flock prevalence of 0.1%, 0.5% and 1% in order. Sensitivity were modeled using the Pert distribution: minimum 75%, most likely 80% and maximum 90% for plate agglutination test and 80%, 85%, and 90% for ELISA test. Similarly, the specificity was modeled 85%, 90%, 95% for plate agglutination test and 90%, 95%, 99% for ELISA test. In accordance with the current regulation, flock-level test characteristics calculated assuming that 30 samples are taken from per flock. The model showed that the current 112,000 annual number of testing plan which is based on random selection of flocks is far beyond the sample size estimated in this study. The sample size was further reduced with increased sensitivity and specificity of the test and decreased WFP. The effect of increasing samples per flock on total sample size to be sampled and optimal combination of sensitivity and specificity of the test for the purpose of the surveillance is discussed regarding cost.

수의학회지 논문에 적용된 통계기법의 타당성 평가

박선일,Pak, Son-il 대한수의학회 1999 大韓獸醫學會誌 Vol.39 No.6

The purpose of this study is to assess the suitability of the statistical techniques employed in papers published in the Korean Journal of Veterinary Research from March 1997 to March 1999 and it is hoped that the critical assessment may be of help to other researchers preparing their works for publication. Of the 246 original papers 94 were included in the analysis. Of 62 papers with the measure of central location and dispersion of data 34 (54.8%) used them correctly : 9 (39.1%) of 23 for t-test ; 1 (33.3%) of 3 for correlation analysis ; 7 (43.8%) of 16 for analysis of variance (ANOVA) ; 5 (62.5%) of 8 for chi-square test ; 44 (71%) of 62 for description of p-value. A number of papers employed ANOVA did not perform subsequent analysis of multiple comparison. Compared to the results of others, relatively higher proportion of papers in the present study was evaluated as appropriate analysis. The reason is that papers described insufficiently on the study design were not included, and evaluation items were restricted to the cases violated seriously inherent assumptions for each statistical technique. Statistical misuse or abuse appeared in the study is due to lack of knowledge on statistics and short of its importance for improvement the quality of paper. Because an inappropriate analysis can lead the readers to misunderstand on findings, observed statistical analyses must be valid, and correctly undertaken. It is suggested that more intensive statistical refereeing are needed, and the communication should be allowed for the controversial points.

국내 돼지오제스키병의 혈청학적 감시활동(surveillance)을 위한 표본크기

김으뜸,박선일,박최규,권창희,Kim, Eu-Tteum,Pak, Son-Il,Park, Choi-Kyu,Kweon, Chang-Hee 대한수의학회 2007 大韓獸醫學會誌 Vol.47 No.4

Serological surveillance programs in animal populations are becoming increasingly important to estimate prevalence of a specific disease and subsequently to document disease-free status in a region or a country. For these purposes, the programs need to be based on both theoretical and economical aspects from the designing phase. From Aujeszky's disease (AD)-eradication program point of view, group of animals (aggregates, herds) not individual animal is the more important sampling unit of concern. In this study the authors therefore attempted to compute an appropriate sample size tailored to a current surveillance program against AD, assuming that the goal of this program is either herd-level prevalence estimation or documentation of AD-freedom. For prevalence estimation, assuming a finite population with imperfect sensitivity (Se) and specificity (Sp) of ELISA kit for AD diagnosis, the number of herds present, expected herd prevalence, and desired accuracy for a certain level of confidence, sample size was estimated at herd-level in the first stage and individual animal-level in the second stage. A two-stage sampling design was used to calculate a sample size to indicate AD-freedom. In this instance, the computation was based on the possible detection of a predetermined prevalence at a certain herd-level Se and Sp. This study indicated that the sample size varied with predetermined confidence, tolerance, Se and Sp at herd- and animal-level, and within- and among-herd prevalence. In general, smaller sample size was required to estimate AD prevalence than to document of AD-freedom. Compared to individual-based samples, two-stage sampling strategy requires a larger sample size to show disease-freedom. Statistical considerations including herd-level test characteristics when designing surveillance program also are further discussed.

확률모형을 이용한 오제스키병 혈청학적 모니터링 프로그램 평가

장기윤,박선일,박최규,이경기,주이석,Chang, Ki-Yoon,Pak, Son-Il,Park, Choi-Kyu,Lee, Kyoung-Ki,Joo, Yi-Seok 대한수의학회 2009 大韓獸醫學會誌 Vol.49 No.2

The objective of this study was to analyze data from the planned national serological monitoring program for Aujeszky's disease (AD) using a simulation model to evaluate probable outcomes expected in the sample derived from the simulated herds at predefined within-herd prevalence and herd prevalence. Additionally, prevalence at animal- and herd-level estimated by the stochastic simulation model based on the distributions of the proportion of infected herds and test-positive animals was compared with those of data from a national serological survey in 2006, in which 106,762 fattening pigs from 5,325 herds were tested for AD using a commercial ELISA kit. A fixed value of 95% was used for test sensitivity, and the specificity was modeled with a minimum, most likely and maximum of 95, 97 and 99%, respectively. The within-herd prevalence and herd prevalence was modeled using Pert and Triang distributions, respectively with a minimum, most likely and maximum point values. In all calculations, population size of 1,000 was used due to lack of representative information. The mean number of infected herds and true test-positives was estimated to be 27 herds (median = 25; 95% percentile 44) and 214 pigs (median = 196; 95% percentile 423), respectively. When testing 20 pigs (mean of 2006 survey) in each herd, there was a 3.3% probability that the potential for false-positive reactions due to less than 100% specificity of the ELISA test would be detected. It was found that the model showed prevalence of 0.21% (99% percentile 0.50%) and 0.5% (99% percentile 0.99%) at animal- and herd-level, respectively. These rates were much similar to data from the 2006 survey (0.62% versus 0.83%). The overall mean herd-level sensitivity of the 2006 survey for fattening pigs was 99.9%, with only a 0.2% probability of failing to detect at least one infected herd.

Malassezia pachydermatis에 의한 개의 피부염 치료 증례

황철용,오태호,박선일,윤화영,한홍율,Hwang, Cheol-yong,Oh, Tae-ho,Pak, Son-il,Youn, Hwa-young,Han, Hong-ryul 대한수의학회 1999 大韓獸醫學會誌 Vol.39 No.5

A 4-year-old female American cocker spaniel was hospitalized with 6 months prolonged dermal problems in The Veterinary Medical Teaching Hospital of Seoul National University. Initial noticed signs by owner of this dog were rashes and papules on ear part and they were spreaded whole body. On initial physical examinations, papules, pustules, crusts, and erythema were presented on whole body. Diameters of focal scaly and erythematous alopetic lesions were varied ranging 1 to 4cm. Skin scraping for detecting ectoparasites and wood's light examinations for dermatophyte were negative. Any bacteria were not detected but Malassezia pachydermatis was detected on cytological examination and fungal culture. The dog was treated with Itraconazole (5mg/kg, q12h) and Cephalexin (20mg/kg, q12h) orally and then bathed with 2% chlorhexidine shampoo twice per week for 5 weeks. From 12 weeks after starting therapy, all dermal problems were disappeared although some mild pyoderma were once relapsed. Regular chlorhexidine bathing treatment so far has been continued for preventing recurrence.

소 질병 검출을 위한 혈청학적 검사의 민감도 평가

이상진,문운경,박선일,Lee, Sang-Jin,Moon, Oun-Kyong,Pak, Son-Il 대한수의학회 2010 大韓獸醫學會誌 Vol.50 No.1

Animal disease surveillance system, defined as the continuous investigation of a given population to detect the occurrence of disease or infection for control purposes, has been key roles to assess the health status of an animal population and, more recently, in international trade of animal and animal products with regard to risk assessment. Especially, for a system aiming to determine whether or not a disease is present in a population sensitivity of the system should be maintained high enough not to miss an infected animal. Therefore, when planning the implementation of surveillance system a number of factors that affecting surveillance sensitivity should be taken into account. Of these parameters sample size is of important, and different approaches are used to calculate sample size, usually depending on the objective of surveillance systems. The purpose of this study was to evaluate the sensitivity of the current national serological surveillance programs for four selected bovine diseases assuming a specified sampling plan, to examine factors affecting the probability of detection, and to provide sample sizes required for achieving surveillance goal of detecting at least an infection in a given population. Our results showed that, for example, detecting low level of prevalence (0.2% for bovine tuberculosis) requires selection of all animals per typical Korean cattle farm (n = 17), and thus risk-based target surveillance for high risk groups can be an alternative strategy to increase sensitivity while not increasing overall sampling efforts. The minimum sample size required for detecting at least one positive animal was sharply increased as the disease prevalence is low. More importantly, high reliability of prevalence estimation was expected with increased sampling fraction even when zero-infected animal was identified. The effect of sample size is also discussed in terms of the maximum prevalence when zero-infected animals were identified and on the probability of failure to detect an infection. We suggest that for many serological surveillance systems, diagnostic performance of the testing method, sample size, prevalence, population size, and statistical confidence need to be considered to correctly interpret results of the system.

뇨중 trypsinogen-2 검출을 이용한 개의 급성 췌장염 진단

한홍율,황철용,박선일,오태호,Han, Hong-ryul,Hwang, Cheol-yong,Pak, Son-il,Oh, Tae-ho 대한수의학회 1999 大韓獸醫學會誌 Vol.39 No.5

We performed this study to evaluate the potential clinical marker of urinary trypsinogen-2 together with amylase, lipase and urinary amylase creatinine clearance ratio (ACCR) for the diagnosis of acute pancreatitis in dogs. In the experiment on daily changing patterns of amylase, lipase and ACCR measurements in experimentally induced pancreatitis dogs, compared to values measured in pre-induction state, significant difference was seen in amylase until 5th day of induction, and for lipase significant difference was found during the 7th day of observation period (p < 0.05). No significant difference was found in ACCR for the study period (p > 0.05). On SDS-PAGE analysis of urine from experimentally induced pancreatitis dog, The 26kd band was markedly increased compared with that of normal state and that band was confirmed trypsinogen-2 using substrate interaction and isoelectric focusing assay after being eluted. When assessing the appearance of 26kd band on urine SDS-PAGE 87.1% (range: 50~100%) of experimentally induced pancreatitis dogs showed positive results, whereas no corresponding band was seen in dog without pancreatic disorders. With this result, determination of urinary trypsinogen-2 assay was found to have a high diagnostic value with a 70% of sensitivity and 100% of specificity as a routine test for pancreatitis, although the detection of trypsinogen-2 in urine can be varied on the progression stage of pancreatitis at the initial visit to animal clinic. We therefore suggest that the promising results in this study be used for the development of dipstick test for detecting acute pancreatitis in the future research.

차량이동 네트워크에서의 축산시설 연결중심성과 가축 전염병 발생 사이의 관계

이경주(Gyoung-Ju Lee),박선일(Son-Il Pak),이광녕(Kwang-Nyeong Lee),김한이(Han-Yee Kim),박진호(Jin-Ho Park),홍성조(Sungjo Hong) 한국산학기술학회 2018 한국산학기술학회논문지 Vol.19 No.12

주기적으로 발생하는 가축전염병으로 인한 국가적 손실이 매우 크다. 또한 우리나라에서 차량이동이 가축전염병의 주요 원인인 것으로 알려져 있다. 이 같은 상황에서, 본 연구는 축산차량의 이동 네트워크에서 축산시설의 구조적 위치와 전염병의 발생 사이의 관계를 실증분석하였다. 이를 위하여 KAHIS에서 제공하는 축산차량의 시설 진입 데이터를 활용하여 축산차량 이동 네트워크를 구축하였다. 구축된 네트워크에서 시설별로 중심성 지표를 도출하고, 전염병이 발생한 시설과 비발생 시설의 지표 평균을 비교하였다. 분석결과 첫번째 가설인 “전염병 발생시설의 연결정도 중심성은 비발생 시설보다 크다.”는 옳은 것으로 나타났다. 전체시점과 시점별 분석을 실시한 결과 대부분의 자료에서 가축전염병이 발생한 시설의 연결정도 중심성이 비발생 시설에 비하여 통계적으로 크게 나타났다. 두 번째 가설인 “HPAI에서 발생시설과 비발생시설 사이의 연결중심성 차이가 FMD에서의 차이보다 작다.”는 전체시점 자료에서 옳은 것으로 나타났다. 반면에 시점을 나누어서 분석한 결과에서는 뚜렷한 차이를 찾을 수 없었다. 연구의결과에 따른 정책적 시사점은다음과 같다. 첫 번째, 연결정도 중심성에 기반한 시설의 사전 관리가 필요하다. 두 번째, 우제류 농가의 경우 연결중심성에 기반한 관리정책의 도입이 보다 시급하다. The national loss caused by the periodic livestock epidemic is very large. In addition, vehicle movement is the main cause of livestock epidemics in Korea. In this context, this study analyzed the relationship between the degree centrality of livestock facilities and the outbreak of infectious diseases. For this purpose, a livestock vehicle movement network was constructed using the facility entrance data provided by KAHIS. Afterwards, the centrality index was derived for each facility in the vehicle movement network and the mean centrality index of the epidemic and non-epidemic facilities were compared. The analysis results are summarized as follows. First, the degree centrality of epidemic facilities is significantly greater than non-epidemic facilities. As a result of the analysis of the entire period data and the period-based data, in most data, the degree centrality of facilities where livestock infectious diseases occurred was significantly greater than most non-occurrence facilities. Second, in the entire period data, the difference in degree centrality between the epidemic and non-epidemic facilities was smaller for HPAI than for FMD. On the other hand, no significant difference was found in the results of the analysis according to the divided period. The policy implications of the results are as follows. First, proactive management of facilities based on centrality is needed. Second, in the case of cloven-hoofed animal facilities, it is more urgent to introduce a management policy based on the degree centrality.

혈청역학적 분석을 통한 한국의 돼지 유행성 설사병 바이러스 감염양상

박최규(Choi-Kyu Park),박선일(Son-Il Pak) 한국생명과학회 2009 생명과학회지 Vol.19 No.9

To investigate the infection patterns of porcine epidemic diarrhea virus (PEDV) in Korean pig farms, a total of 4,768 swine sera samples from 159 pig farms were taken twice, in June (n=82) and October (n=77) in 2007. In each farm selected for the survey, 10 samples from breeding pigs and 4 from each of the 5 age groups (30, 60, 90, 120, and 150 days) were taken, and all serum samples were tested for PEDV by the serum neutralization test. The overall seroprevalence was 62.6% (2,983/4,768), with the highest prevalence in breeding pigs (93.5%, 1,485/1,589). The prevalence showed an increasing trend with increasing age (30.8, 27.2, 44.7, 61.6, and 71.2% respectively in the 30, 60, 90, 120, and 150 days age groups) (p<0.0001 for x² trend test). The association between age and PEDV prevalence was similar in both surveys, indicating that the infection of PEDV seemed to be occurring repeatedly in the farms surveyed. This inference could also be explained by the fact that prevalence in sows was very high despite low vaccination coverage, as they are continuously exposed to PEDV in potentially infected farms for a longer period. Based on the neutralizing antibody levels in sows and growing pigs, the majority of farms (91.8%, n=146 farms) were endemically infected with PEDV, and most of pigs seemed to be intensively infected with PEDV at around early growth (41.8%) and weaning (31.5%). On the other hand, serum neutralizing antibodies were not detected in pigs older than 30 days of age in farms classified as having no PEDV infection (n=13 farms), indicating the level of maternal antibody against PEDV is decreased on a non-detectable level before the piglet is 60 days old in the field situation. The results indicated that most farms surveyed in 2007 were affected with endemic PEDV infection. Therefore, a national monitoring and control program for the endemic type PEDV infection needs further attention.