• 제목/요약/키워드: asymptomatic infection

검색결과 221건 처리시간 0.03초

Experimental transmission of red sea bream iridovirus (RSIV) between rock bream (Oplegnathus fasciatus) and rockfish (Sebastes schlegelii)

  • Min, Joon Gyu;Jeong, Ye Jin;Jeong, Min A;Kim, Jae-Ok;Hwang, Jee Youn;Kwon, Mun-Gyeong;Kim, Kwang Il
    • 한국어병학회지
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    • 제34권1호
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    • pp.1-7
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    • 2021
  • Red sea bream iridovirus (RSIV), belonging to the genus Megalocytivirus, is the predominant cause of mortality in marine fishes in Korea, including rock bream (Oplegnathus fasciatus). Rockfish (Sebastes schlegelii) are the host fish for RSIV, exhibiting no clinical signs or mortality. Cohabitation challenges, which mimicked natural transmission conditions, were performed to evaluate viral transmission between rock bream and rockfish, and to determine the pathogenicity and viral loads. In cohabitation challenge, artificially RSIV-infected rock bream were the viral donor, and healthy rockfish were the recipient. The results showed that although the donor rock bream had 95-100 % cumulative mortality (>108 viral genome copies/mg of spleen 7-14 days after viral infection), the recipient rockfish did not die, even when the viral genome copies in the spleen were >105 copies/mg. These results indicated asymptomatic infections. Notably, in a reverse-cohabitation challenge (artificially RSIV-infected rockfish as the viral donor and healthy rock bream as the recipient), RSIV horizontally infected from subclinical rockfish to rock bream (107 viral genome copies/mg of spleen 21 days after cohabitation) with 10-20% cumulative mortality. These results suggest that an asymptomatic, infected rockfish can naturally transmit the RSIV without being sacrificed.

울주군에서 발생한 장출혈성대장균 감염증의 발생 원인 (Cause of Enterohemorrhagic Escherichia coli Infection in Ulju County, Korea)

  • 이상원;양병국;이복권;박재구;황병훈;임현술;배근량
    • Journal of Preventive Medicine and Public Health
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    • 제36권1호
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    • pp.77-84
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    • 2003
  • Objectives : Two related cases of Hemolytic-Uremic Syndrome (HUS) were reported to the Korea National Institute of Health in May, 2001. Shiga toxin 2 genes were detected in both stool samples. We suspected an enterohemorrhagic Escherichia coli (EHEC) infection as the cause of the HUS, and conducted an investigation to find the source of the infection and its route of transmission. Methods : We peformed case investigations on these two related HUS cases, and obtained interviews and rectal swabs form the family members and other close contacts. Additionally, we peformed rectal swabs on the cattle raised by the household of the index patient. Results : We found a 20 month old index patient and a 6 year-old cousin had developed HUS, where there had been a 2 day history of contact with the index, and bacteriological examinations for these two patients revealed, indistinguishably, the same E. coli O171. The grandmother of the index patient was found to be asymptomatic, but E. coli O26 was isolated. We also found a probable case in the mother of the cousin. She reported a history of contact with the index, and developed bloody diarrhea of 3 days duration. The test results for the cattle revealed E. coli O26 in one cow, and E. coli O26 and O55 in another. E. coli O26, which was isolated in both cows and the grandmother of the index, were indistinguishably the same. Conclusions : We found that the E. coli O26 in the grandmother had originated from the cows, and that the E. coli O171 found in the index patient had been transmitted to the cousin through person-to-person contact.

COVID-19 바이러스 잠복 시간 분포 추정과 치사율 추정을 위한 생존 분석의 적용 (Statistical analysis of estimating incubation period distribution and case fatality rate of COVID-19)

  • 기한정;김지은;김소희;박주원;이주행;김양진
    • 응용통계연구
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    • 제33권6호
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    • pp.777-789
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    • 2020
  • COVID-19는 지난 2019년 12월부터 중국에서 발생하여 전세계적으로 확산된 대유행병이 되었다. 본 연구에서는 한국 질병 관리 본부에서 공개한 오픈 자료를 이용하였으며 시각화 기법을 통해 확진자의 남녀별 지역별 추세를 조사하였다. 또한 평균 바이러스 잠복기간을 추정하기 위해 감염원이 알려진 두 감염 그룹의 증상 발현 시점과 양성 확진 시점을 활용하였다. 하지만 양성 확진자 중 86%가 무증상으로 정확한 증상 발현시점을 알 수 없었다. 또한 주어진 자료에서는 감염시점도 알려져 있지 않아 감염시점과 증상 발현 시점차로 정의되는 잠복기간은 정확하게 측정하기가 어렵다. 이에 생존 분석의 한 기법인 구간 중도 절단을 적용하여 잠복기간의 분포를 추정하였다. 여러가지 모수 분포를 적용한 결과 최적의 분포하에서 평균 잠복 기간은 5.4일 (95% 신뢰구간 (4.70,6.01)일)이었다. 본 분석에서는 확진자 표본을 이용하여 치사율과 치유율을 구하기 위해 경쟁 위험 모형을 적용하였다. 분석 결과 50대이상의 치사 위험률은 50대미만 그룹의 30배이상이며 남성 양성 확진자가 사망할 확률이 더 높았다. 또한 여성이고 나이가 젊고 무증상일 때 치유될 가능성이 더 높았다.

Prevalence of Trichomonas vaginalis by PCR in Men Attending a Primary Care Urology Clinic in South Korea

  • Seo, Jun-Hyeok;Yang, Hye-Won;Joo, So-Young;Song, Su-Min;Lee, Yu-Ran;Ryu, Jae-Sook;Yoo, Eun Sang;Lee, Won Kee;Kong, Hyun-Hee;Lee, Sang-Eun;Lee, Won-Ja;Goo, Youn-Kyoung;Chung, Dong-Il;Hong, Yeonchul
    • Parasites, Hosts and Diseases
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    • 제52권5호
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    • pp.551-555
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    • 2014
  • Trichomonas vaginalis, a causative agent of trichomoniasis, may trigger symptomatic or asymptomatic non-gonococcal urethritis and chronic prostatitis in men. Despite the availability of highly sensitive diagnostic tests, such as nucleic acid amplification tests, including PCR, few prospective studies present data on male T. vaginalis infection in South Korea. In the present study, the prevalence of T. vaginalis and associated clinical conditions were evaluated in 201 male patients from a primary care urology clinic in South Korea. The prevalence of T. vaginalis infection in our cohort was 4% (8/201) by PCR. T. vaginalis infection was common in men older than 40 years (median age, 52 years). Among the 8 Trichomonas-positive patients, 87.5% (7/8) had prostatic diseases, such as prostatitis and benign prostatic hyperplasia, and 25.0% (2/8) and 12.5% (1/8) were coinfected with Chlamydia trachomatis and Mycoplasma genitalium, respectively. Our results suggest that T. vaginalis infection is not rare in men attending primary care urology clinics in South Korea, especially in those older than 40 years, in whom it may explain the presence of prostatic disease. The possibility of T. vaginalis infection should be routinely considered in older male patients with prostatic diseases in South Korea.

Hepatitis C Virus - Proteins, Diagnosis, Treatment and New Approaches for Vaccine Development

  • Keyvani, Hossein;Fazlalipour, Mehdi;Monavari, Seyed Hamid Reza;Mollaie, Hamid Reza
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권12호
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    • pp.5917-5935
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    • 2012
  • Background: Hepatitis C virus (HCV) causes acute and chronic human hepatitis infection and as such is an important global health problem. The virus was discovered in the USA in 1989 and it is now known that three to four million people are infected every year, WHO estimating that 3 percent of the 7 billion people worldwide being chronically infected. Humans are the natural hosts of HCV and this virus can eventually lead to permanent liver damage and carcinoma. HCV is a member of the Flaviviridae family and Hepacivirus genus. The diameter of the virus is about 50-60 nm and the virion contains a single-stranded positive RNA approximately 10,000 nucleotides in length and consisting of one ORF which is encapsulated by an external lipid envelope and icosahedral capsid. HCV is a heterogeneous virus, classified into 6 genotypes and more than 50 subtypes. Because of the genome variability, nucleotide sequences of genotypes differ by approximately 31-34%, and by 20-23% among subtypes. Quasi-species of mixed virus populations provide a survival advantage for the virus to create multiple variant genomes and a high rate of generation of variants to allow rapid selection of mutants for new environmental conditions. Direct contact with infected blood and blood products, sexual relationships and availability of injectable drugs have had remarkable effects on HCV epidemiology. Hundreds of thousands of people die each year from hepatitis and liver cancer caused by HCV virus infection. Approximately 80% of patients with acute hepatitis C progress into a chronic disease state leading to serious hepatic disorders, 10-20% of which develop chronic liver cirrhosis and hepatocellular carcinoma. The incubation period of HCV is 6-8 weeks and the infection is often asymptomatic so it is very hard to detect at early stages, making early treatment very difficult. Therefore, hepatitis C is called a "silent disease". Neutralizing antibodies are produced against several HCV proteins during infection but the virus mutates to escape from antibodies. Some patients with chronic hepatitis C may have some symptoms such as fatigue, muscle aches, nausea and pain. Autoimmune and immunecomplex-mediated diseases have also been reported with chronic HCV infection.

대전·충남지역 개에서 지알디아증 유병률 (Prevalence of Canine Giardiasis in the Daejeon and Chungnam Area)

  • 정대욱;이상은;유명조;서경원;송근호
    • 한국임상수의학회지
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    • 제32권6호
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    • pp.477-480
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    • 2015
  • 본 연구는 한국의 대전과 충남 지역에 있는 개 100마리에서 실내견 (25마리)과 실외견 (75마리)을 구분하여 지알디아증의 유병률을 조사하였다. 모든 샘플은 Giardia SNAP 키트($SNAP^{(R)}$ test, IDEXX Laboratories, Inc., Westbrook, ME)를 이용하여 감염여부를 조사하였다. 지알디아증은 실외견(11/75, 14.66%)이 실내견(1/25, 4.00%) 보다 유의성 있는 높은 유병률은 나타내었다. 또한 자견(< 2yr: 10/51, 19.60%)이 성견(> 2yr: 2/49, 4.08%) 보다 유의성 있는 높은 유병률은 나타내었다. 임상증상을 나타내는 개는 증상이 없는 개보다 높은 유병률을 나타내었으나 (증상: 4/22, 18.18%, 무증상: 9/78, 11.54%) 통계학적으로 유의하지는 않았다. 실외견 중 분리되어 단독으로 기르는 개(2/50, 4.00%)보다 합사하여 여러 마리가 같이 생활하는 개(9/25, 36.00%)에서 높은 유병률을 나타내었다. 세계 여러 나라의 다양한 지역에서 지알디아증 유병률에 대한 조사는 많이 진행되었으나, 사육 패턴에 따른 유병률을 평가한 적은 없기에 본 연구의 의의가 있다.

B형 간염 바이러스(Hepatitis B Virus)에 의한 신장병증 1예 (A Case of Hepatitis B Virus Associated Nephropathy)

  • 김태년;이영곤;윤경우;김종설
    • Journal of Yeungnam Medical Science
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    • 제3권1호
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    • pp.325-332
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    • 1986
  • 저자들은 16세 남자 환자에서 만성 지속성 간염 및 막증식성 사구체신염(type I)이 발생한 Hepatitis B virus associated nephropathy 1예(例)를 경험하였기에 보고하는 바이며, 특히 우리나라는 B형 간염 바이러스의 나환율(羅患率)이 높기 때문에 B형 간염과 연관된 신질환의 빈도도 높을 것으로 추정(推定)되며, 그 중요성도 클 것으로 사료(思料)된다. 따라서 향후(向後) Hepatitis B virus associated nephropathy의 발생 기전 및 치료법에 관한 체계적인 연구가 필요할 것으로 생각된다.

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Plasma Real Time-Quantitative Polymerase Chain Reaction of Epstein-Barr Virus in Immunocompetent Patients with Hepatitis

  • Hong, Ji-Hye;Bae, Yon-Jung;Sohn, Joon-Hyung;Ye, Byung-Il;Chun, Jin-Kyong;Kim, Hwang-Min
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제15권1호
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    • pp.38-43
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    • 2012
  • Purpose: Epstein-Barr virus (EBV) hepatitis is a usually asymptomatic and self-limiting disease in immunocompetent patients. However, the range of severity is wide, and the serological diagnosis is typically difficult until the convalescent phase. Thus, we examined the value of plasma EBV DNA real-time quantitative polymerase chain reaction (RT-qPCR) in EBV hepatitis for the timely diagnosis and the relationship between EBV viral load and clinical severity. Methods: Sixty samples were confirmed as having EBV infection by RT-qPCR with the EBV BALF5 gene sequence. We examined the clinical characteristics of EBV hepatitis by reviewing medical records. Results: The median total duration of fever was 8 days (range: 0-13 days). The mean peak value of aspartate aminotransferase (AST) was $241{\pm}214$ U/L, and the mean peak value of alanine aminotransferase (ALT) was $298{\pm}312$ U/L. There was no correlation between the serum levels of liver enzyme and plasma EBV DNA titer ($p$=0.1) or between median total duration of fever and EBV DNA titer ($p$=0.056). The median age of the EBV VCA IgM-negative group was lower compared with the EBV VCA IgM-positive group in EBV hepatitis (2 years vs. 6 years, $p$=0.0009). Conclusion: The severity of EBV hepatitis does not correlate with circulating EBV DNA load according to our data. Furthermore, we suggest that plasma EBV PCR may be valuable in young infants in whom the results of serology test for EBV infection commonly are negative.

횡문근융해증에 의한 급성 신 손상이 동반된 렙토스피라증 1예 (Rhabdomyolysis Induced Acute Kidney Injury in a Patient with Leptospirosis)

  • 최윤정;박정민;정요한;남종호;정현희;김태우;조규향;도준영;윤경우;박종원
    • Journal of Yeungnam Medical Science
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    • 제28권1호
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    • pp.54-59
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    • 2011
  • Leptospirosis is a spirochetal infectious disease caused by $Leptospira$ $interrogans$, and may vary in degree from an asymptomatic infection to a severe and fatal illness. The kidney is one of the principal target organs of $Leptospira$. Renal disorders caused by $Leptospira$ infection vary from an abnonnality in urinalysis to acute kidney injury (AKI). Incidence of AKI in severe leptospirosis varies from 40% to 60%. AKI reflects the severity of leptospirosis and is generally accompanied by cholestatic jaundice. The pathophysiology of AKI in leptospirosis consists of hypovolemia, direct tubular toxicity, and rhabdomyolysis. Most patients with acute leptospirosis experience severe myalgias, and show laboratory evidence of mild rhabdomyolysis. However, occurrence of severe rhabdomyolysis is rare. We report here on a patient with leoptospirosis, who had severe rhabdomyolysis and acute kidney injury without jaundice.

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Gender Reassignment Surgery in Human Immunodeficiency Virus-Positive Patients: A Report of Two Cases

  • Kim, Seok-Kwun;Choi, Ji-An;Kim, Myung-Hoon;Kim, Min-Su;Lee, Keun-Cheol
    • Archives of Plastic Surgery
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    • 제42권6호
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    • pp.776-782
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    • 2015
  • It is believed that surgery on human immunodeficiency virus (HIV)-positive patients is dangerous and should be avoided due to the possibility of postoperative infection of the patients or HIV occupational transmission to the medical staff. We discuss here the preparations and measures needed to conduct surgery safely on HIV-positive patients, based on our experience. We performed sex reassignment surgery on two HIV-positive patients from January 2013 to January 2015. Both of them were receiving highly active antiretroviral therapy and were asymptomatic, with a normal CD4 count ($>500cells/{\mu}L$). The HIV-RNA was undetectable within the bloodstream. All the staff wore protective clothing, glasses, and three pairs of protective gloves in the operating room because of the possibility of transmission. Prophylactic antibiotics were administered to the patients, and antiviral therapy was performed during their perioperative course. Neither of the patients had postoperative complications, and none of the medical staff experienced accidental exposure. Both patients had satisfactory surgery outcomes without complications. HIV-positive patients can undergo surgery safely without increased risk of postoperative complications or HIV transmission to the staff through the proper use of antibiotics, active antiretroviral therapy, and supplemental protective measures with post-exposure prophylaxis for the staff in case of HIV exposure.