• Tuberculosis and Respiratory Diseases
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• 제79권2호
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• pp.70-73
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• 2016

In late March of 2009, an outbreak of influenza in Mexico, was eventually identified as H1N1 influenza A. In June 2009, the World Health Organization raised a pandemic alert to the highest level. More than 214 countries have reported confirmed cases of pandemic H1N1 influenza A. In Korea, the first case of pandemic influenza A/H1N1 infection was reported on May 2, 2009. Between May 2009 and August 2010, 750,000 cases of pandemic influenza A/H1N1 were confirmed by laboratory test. The H1N1-related death toll was estimated to reach 252 individuals. Almost one billion cases of influenza occurs globally every year, resulting in 300,000 to 500,000 deaths. Influenza vaccination induces virus-neutralizing antibodies, mainly against hemagglutinin, which provide protection from invading virus. New quadrivalent inactivated influenza vaccine generates similar immune responses against the three influenza strains contained in two types of trivalent vaccines and superior responses against the additional B strain.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.699-707
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• 2012

Since the 2009 pandemic human H1N1 influenza A virus emerged in April 2009, novel reassortant strains have been identified throughout the world. This paper describes the detection and isolation of reassortant strains associated with human pandemic influenza H1N1 and swine influenza H1N2 (SIV) viruses in swine populations in South Korea. Two influenza H1N2 reassortants were detected, and subtyped by PCR. The strains were isolated using Madin-Darby canine kidney (MDCK) cells, and genetically characterized by phylogenetic analysis for genetic diversity. They consisted of human, avian, and swine virus genes that were originated from the 2009 pandemic H1N1 virus and a neuraminidase (NA) gene from H1N2 SIV previously isolated in North America. This identification of reassortment events in swine farms raises concern that reassortant strains may continuously circulate within swine populations, calling for the further study and surveillance of pandemic H1N1 among swine.

• 기술사
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• 제42권6호
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• pp.42-46
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• 2009

Every year influenza contributes to the death of 72 people in the South korea, 20,000 in the U.S. and perhaps millions worldwide. The swine fever so-called the noble flu A H1N1, a strain of the flu virus, which jumped species and burst into the human population in March and April of this year. The outbreak of 2009 novel H1N1 was the fourth in 100 years. Fortunately, it led to today's comparatively tame swine flu than the vicious 1918, which was original H1N1 pandemic flu virus, killed at least 40 million worldwide in an ongoing pandemic era. Although the 2009 H1N1 which is still in full swing, this global flu epidemic is already teaching scientists valuable lessons about pandemics. Evidence accumulated these days indicates that the 2009 H1N1 was not entirely new to all human immune systems. This article introduces only an outline for our better understanding the basic mechanisms of influenza and the vaccination about longstanding fears of that worst-case scenario engendered pandemic that are paying off today.

• 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.

• Clinical and Experimental Pediatrics
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• 제54권8호
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• pp.329-334
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• 2011

Purpose: The purpose of this article is to describe the clinical and epidemiologic features and outcomes among children hospitalized with pandemic influenza A/H1N1 2009 infection. Methods: We retrospectively reviewed the charts of hospitalized pediatric patients (<18 years) diagnosed with pandemic influenza A/H1N1 2009 infection by reverse-transcriptase polymerase chain reaction at a tertiary hospital in Seoul, Korea, between September 2009 and February 2010. Results: A total of 72 children were hospitalized with pandemic influenza A/H1N1 2009 infection (median age, 6.0 years; range, 2 months to 18 years). A total of 40% had at least 1 underlying medical condition, including asthma (17%), malignancies (19%), and heart diseases (17%). Of the 72 patients, 54 (76%) children admitted with H1N1 infection showed radiographic alterations compatible with pneumonia. There was no significant difference in pre-existing conditions between pandemic influenza A/H1N1 infected patients with or without pneumonia. Children with pandemic influenza A/H1N1 pneumonia were more likely to have a lower lymphocyte ratio (P=0.02), higher platelet count (P=0.02), and higher level of serum glucose (P=0.003), and more commonly presented with dyspnea than did those without pneumonia (P=0.04). Conclusions: No significant differences in age, sex, or presence of preexisting conditions were found between children hospitalized with pandemic influenza A/H1N1 H1N1 influenza infection with pneumonia and those without pneumonia. Higher leukocyte count, higher glucose level, and a lower lymphocyte ratio were associated with the development of pandemic A/H1N1 2009 influenza pneumonia.

• Pediatric Infection and Vaccine
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• 제19권2호
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• pp.61-70
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• 2012

목적: 본 연구는 단일 기관에서 소아암 환자의 2009 인플루엔자 A(H1N1) [A(H1N1)pdm09] 감염 양상을 조사하고 이전의 계절 인플루엔자 감염과 비교 분석하고자 하였다. 방법: 삼성서울병원에서 2009년 8월부터 2010년 2월까지 A(H1N1)pdm09 감염, 2000년 1월부터 2009년 5월까지 계절 인플루엔자 A 감염이 확진된 소아암 환자의 의무기록을 후향적으로 분석하였다. 결과: 82명의 소아암 환자에서 A(H1N1)pdm09 감염이 확진되었다. 10명(12.2%)의 환자에서 하기도 감염증 또는 호흡기 외 감염이 발생하였다. 3명(3.7%)의 환자가 사망하였고 그 중 2명은 A(H1N1)pdm09 기여 사망이었다. 합병된 감염증과 관련하여 유의성을 가지는 위험인자는 감염의 시점(2009년 44-45주)과 병원 내 감염이었다. 이전의 계절 인플루엔자 A 감염과 비교하였을 때 임상적 특성에는 유의한 차이가 없었으나 A(H1N1) pdm09 감염에서 적극적인 항바이러스제 치료가 시행되었다. 결론: 소아암 환자에서 A(H1N1)pdm 감염은 경증부터 중증까지 다양한 임상 경과를 보였으며 이전의 계절 인플루엔자와 비교했을 때 임상 양상의 유의한 차이는 없었다.

• BMB Reports
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• 제45권11호
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• pp.653-658
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• 2012

After the outbreak of the swine-origin influenza A H1N1 virus in April 2009, World Health Organization declared this novel H1N1 virus as the first pandemic influenza virus (2009 pH1N1) of the $21^{st}$ century. To elucidate the characteristics of 2009 pH1N1, the growth properties of A/Korea/01/09 (K/09) was analyzed in cells. Interestingly, the maximal titer of K/09 was higher than that of a seasonal H1N1 virus isolated in Korea 2008 (S/08) though the RNP complex of K/09 was less competent than that of S/08. In addition, the NS1 protein of K/09 was determined as a weak interferon antagonist as compared to that of S/08. Thus, in order to confine genetic determinants of K/09, activities of two major surface glycoproteins were analyzed. Interestingly, K/09 possesses highly reactive NA proteins and weak HA cell-binding avidity. These findings suggest that the surface glycoproteins might be a key factor in the features of 2009 pH1N1.

• Tuberculosis and Respiratory Diseases
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• 제70권4호
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• pp.285-292
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• 2011

After an outbreak of H1N1 influenza A virus infection in Mexico in late March 2009, the World Health Organization raised its pandemic alert level to phase 6, and to the highest level in June 2009. The pandemic H1N1/A influenza was caused by an H1N1 influenza A virus that represents a quadruple reassortment of two swine strains, one human strain, and one avian strain of influenza. After the first case report of H1N1/A infection in early May 2009, South Korea was overwhelmed by this new kind of influenza H1N1/A pandemic, which resulted in a total of 700,000 formally reported cases and 252 deaths. In this article, clinical characteristics of victims of H1N1/A influenza infection, especially those who developed pneumonia and those who were cared for in the intensive care unit, are described. In addition, guidelines for the treatment of H1N1/A influenza virus infection victims in the ICU, which was suggested by the Korean Society of Critical Care Medicine, are introduced.

• 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.

• 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%.