• Tuberculosis and Respiratory Diseases
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• 제70권3호
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• pp.247-250
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• 2011

The pandemic (H1N1) 2009 influenza outbreak coincided with the typical Scrub typhus season, which can lead to diagnostic difficulties due to their similar and non-specific symptoms. Here we describe a case of laboratory confirmed co-infection of Pandemic (H1N1) 2009 influenza and Scrub typhus and discuss the difficulties in distinguishing the two illnesses clinically.

• Clinical and Experimental Pediatrics
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• 제54권10호
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• pp.405-408
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• 2011

Purpose: In autumn 2009, the swine-origin influenza A (H1N1) virus spread throughout South Korea. The aims of this study were to determine the clinical characteristics of children infected by the 2009 H1N1 influenza A virus, and to compare the rapid antigen and realtime polymerase chain reaction (PCR) tests. Methods: We conducted a retrospective review of patients ${\geq}18$ years of age who presented to Soonchunhyang University Hospital in Seoul with respiratory symptoms, including fever, between September 2009 and January 2010. A real-time PCR test was used to definitively diagnose 2009 H1N1 influenza A infection. Medical records of confirmed cases were reviewed for sex, age, and the time of infection. The decision to perform rapid antigen testing was not influenced by clinical conditions, but by individual factors such as economic conditions. Its sensitivity and specificity were evaluated compared to real-time PCR test results. Results: In total, 934 patients tested positive for H1N1 by real-time PCR. The highest number of patients (48.9%) was diagnosed in November. Most patients (48.2%) were aged between 6 and 10 years. Compared with the H1N1 real-time PCR test results, the rapid antigen test showed 22% sensitivity and 83% specificity. Seventy-eight patients were hospitalized for H1N1 influenza A virus infection, and fever was the most common symptom (97.4%). Conclusion: For diagnosis of 2009 H1N1 influenza A virus infection, the rapid antigen test was inferior to the real-time PCR test in both sensitivity and specificity. This outcome suggests that the rapid antigen test is inappropriate for screening.

• 한국동물위생학회지
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• 제45권1호
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• pp.31-38
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• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.

• 대한간호학회지
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• 제41권3호
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• pp.403-410
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• 2011

Purpose: This study was to identify the current status of vaccination against the pandemic (H1N1) 2009 virus among university students from the fields of nursing and allied health from a local community and verify factors influencing vaccination. Methods: The study included 227 students in the fields of nursing and allied health from a provincial university. Data were obtained from these participants between May 31 and June 11, 2010 by using self-report questionnaires. Results: The rate of vaccination against the pandemic (H1N1) 2009 virus for these participants was 14.5%. No difference was observed in this regard between majors and school year. Factors that influence vaccination against this virus included previous vaccination against seasonal influenza and participants’ attitudes toward general vaccination. Conclusion: The results suggest that for effective pandemic (H1N1) 2009 vaccination of university students from the fields of nursing and allied health, students who have not been vaccinated should be intensively managed. Developing a vaccination program that encourages a positive attitude toward vaccination is recommended.

• 미생물학회지
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• 제55권1호
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• pp.25-32
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• 2019

Influenza A (H1N1) virus caused a worldwide pandemic in 2009-2010 and still remains in seasonal circulation. Continuous surveillance activities are encouraged in the post pandemic phase to watch over the trend of occurrence every year, this is better to be done by a rapid and sensitive method for its detection. This study was conducted to detect proportions of occurrence of influenza A virus (H1N1) in patients with influenza-like illness. Samples from 500 patients with influenza or influenza-like clinical presentation were tested by real-time reverse transcription polymerase chain reaction (RT-PCR) and virus tissue culture. Among the total 500 participants, 193 (38.6%) were females and 307 (61.4%) males. Seventy-one patients (14.2%) were positive for H1N1 virus infection with real-time RT-PCR while 52 (10.4%) were positive by tissue culture. Non-statistically significant relation was found between age and gender with the positivity of H1N1. Sensitivity and specificity of real-time RT-PCR was 98.08% and 95.54%, respectively, in comparison to virus isolation with accuracy 95.8%. This study showed that H1N1 virus was responsible for a good proportion of influenza during the post-pandemic period. Real-time RT-PCR provides rapidity and sensitivity for the detection of influenza A virus (H1N1) compared with virus isolation and thus it is recommended as a diagnostic tool.

• IMMUNE NETWORK
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• 제16권5호
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• pp.311-315
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• 2016

A pandemic influenza A (H1N1) virus strain was isolated from a pig farm in Korea in December 2009. The strain was propagated in and isolated from both the Madin-Darby canine kidney cell line and embryonated eggs. The partial and complete sequences of the strain were identical to those of A/California/04/2009, with >99% sequence similarity in the HA, NA, M, NS, NP, PA, PB1, and PB2 genes. The isolated strain was inactivated and used to prepare a swine influenza vaccine. This trial vaccine, containing the new isolate that has high sequence similarity with the pandemic influenza A (H1N1) virus, resulted in seroconversion in Guinea pigs and piglets. This strain could therefore be a potential vaccine candidate for swine influenza control in commercial farms.

• Tuberculosis and Respiratory Diseases
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• 제70권1호
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• pp.28-35
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• 2011

Background: The aim of the study was to describe the characteristics, treatments, and outcomes of critically ill patients with pandemic Influenza A/H1N1 2009 at a major medical center in Korea. Methods: This retrospective observational study examined critically ill adult patients with pandemic Influenza A/H1N1 2009, who were admitted to the AMC between August and December 2009. Results: 27 patients with confirmed pandemic Influenza A/H1N1 2009 were admitted to the intensive care unit (ICU) at the Asan Medical Center (AMC). The median age (IQR) was 59 years (41~67), and 66.7% of the patients were older than 51 years. A total of 81.5% of the patients had 2 or more co-morbidities. The median time (IQR) from symptom onset to presentation was 2 days (1~4), and the median time from presentation to ICU admission was 0 days (0~1.5). All patients received oseltamivir (300 mg/day) and 13 patients received triple combination therapy (oseltamivir, amantadine, ribavirin). Twelve patients required mechanical ventilation on the first day of ICU admission. A total of 6 patients (22.2%) died within 28 days of admission. The patients who died had significantly higher acute physiology and chronic health evaluation (APACHE) II and sequential organ failure assessment (SOFA) scores at presentation. There were no significant differences in age, co-morbidities, or antiviral regimens between survivors and non-survivors. Conclusion: Critical illness related to pandemic Influenza A/H1N1 2009 was common in elderly patients with chronic co-morbidities. All patients were given high-dose oseltamivir or triple combination antiviral therapy. Nonetheless, patients with critical illnesses associated with pandemic Influenza A/H1N1 2009 had a death rate of 22.2%.

• 한국간호교육학회지
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• 제16권2호
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• pp.249-256
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• 2010

Purpose: This study was performed to identify the affecting factors on health behavior of university students during pandemic Influenza A (H1N1). Method: The participants in this study were 283 students in H university. Data were collected through self-reported questionnaires in September, 2009. The collected data were analyzed by ANOVA, Pearson correlation and stepwise multiple regression using SPSS/WIN 18.0. Result: The percentage of correct answers regarding knowledge of Influenza A (H1N1) was 34.6%. Risk perception and compliance of health behavior were very poor, $17.92{\pm}6.26/30$ and $2.00{\pm}1.68/9$, respectively. There was a positive correlation among knowledge, risk perception and health behavior. Knowledge and risk perception of Influenza A (H1N1) and intention of getting an influenza vaccination for this year explained 16.3% of variance in health behavior. Conclusion: An educational program focusing on strategy to enhance university students' knowledge and risk perception of Influenza A (H1N1) would be effective in improving their health behavior against it.

• Pediatric Infection and Vaccine
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• 제18권2호
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• pp.173-181
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• 2011

목 적 : 신종 인플루엔자 A (H1N1) 바이러스는 2009년 4월 멕시코에서 처음 확인된 후 급속히 전 세계로 확산되어 국내에서도 전국적인 유행을 보였다. 저자들은 2009-2010에 소아에서 유행한 신종 인플루엔자 A (H1N1) 바이러스 감염의 임상적, 역학적 특징을 알아보고자 하였다. 방 법: 2009년 8월부터 2010년 2월까지 대구파티마병원 소아청소년과에서 신종 인플루엔자 A (H1N1) 바이러스 감염으로 확진되었던 2,781명을 대상으로 하였다. 확진은 비인두 가검물을 채취하여 중합효소 연쇄반응 검사에서 양성을 보인 경우로 하였다. 의무기록지를 후향적으로 분석하였다. 결 과: 6,786명이 RT-PCR 검사를 받았으며 그중 2,781이 양성이었다. 158명(5.7%)이 입원치료를 받았으며, 입원군의 평균연령($5.4{\pm}3.3$세)이 비입원군($7.5{\pm}3.9$세)에 비해 의미 있게 낮았다(P<0.001). 입원군 중에서 산소치료, 면역글로불린 및 스테로이드 치료, 인공호흡기 치료가 필요했던 경우는 폐렴 환자에 비해 천명음이 동반한 폐렴 환자에서 의미있게 많았으며(P=0.013), 폐렴군에서도 기관지성 폐렴에 비해 분절성, 대엽성, 간질성 혼합성, 흉수가 동반된 경우에 보다 적극적인 치료가 필요하였다(P=0.007). 확진 환자 중 1세 미만의 영아는 83명이었고 그중 71명에서 oseltamivir 처방이 이루어졌고 항바이러스제 사용으로 인한 특이한 이상 소견은 발견되지 않았다. 결 론: 2009-2010에 대유행한 A형 인플루엔자 바이러스(H1N1)는 어린 연령 군에서 더 입원치료가 더 많이 필요하였다. 천명음이 동반된 폐렴경우 그리고 분절성, 대엽성, 간질성, 혼합성 폐렴이거나 흉수가 동반된 경우는 조기에 적극적인 치료가 필요하다고 생각된다.

• Tuberculosis and Respiratory Diseases
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• 제70권6호
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• pp.490-497
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• 2011

Background: It is difficult but important to differentiate between bacterial and viral infections, especially for respiratory infections. Hence, there is an ongoing need for sensitive and specific markers of bacterial infections. We investigated novel biomarkers for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infections. Methods: This was a prospective, observational study of patients with community acquired bacterial pneumonia, 2009 H1N1 Influenza A infection, and healthy controls. Serum samples were obtained on the initial visit to the hospital and stored at $-80^{\circ}C$. We evaluated CRP (C-reactive protein), PCT (procalcitonin), LBP (lipopolysaccharide-binding protein) and copeptin. These analytes were all evaluated retrospectively except CRP. Receiver operating characteristic curve (ROC) analyses were performed on the resulting data. Results: Enrolled patients included 27 with community acquired bacterial pneumonia, 20 with 2009 H1N1 Influenza A infection, and 26 who were healthy controls. In an ROC analysis for discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection, areas under the curve (AUCs) were 0.799 for CRP (95% Confidence interval [CI], 0.664~0.934), 0.753 for PCT (95% CI, 0.613~0.892) and 0.684 for LBP (95% CI, 0.531~0.837). Copeptin was not different among the three groups. Conclusion: These findings suggest that serum CRP, PCT and LBP can assist physicians in discriminating community acquired bacterial pneumonia from 2009 H1N1 influenza A infection.