• Clinical and Experimental Pediatrics
• /
• 제52권8호
• /
• pp.862-868
• /
• 2009

Since its identification in April 2009, a swine-origin H1N1 influenza A virus (S-OIV) which is a reassortment of gene segments from both North American triple-reassortant and Eurasian swine influenza has been widely spread among humans in unexpected rapidity. To date, each gene segment of the 2009 influenza A (H1N1) outbreak viruses have shown high (99.9%) neucleotide sequence identity. As of July 6, 94,512 people have been infected in 122 countries, of whom 429 have died with an overall case-fatality rate of <0.5%. Most confirmed cases of S-OIV infection have been characterized by self-limited, uncomplicated febrile respiratory illness and 38% of cases have also included vomiting or diarrhea. Standard plus droplet precautions should be adhered to at all times. Tests on S-OIV have indicated that current new H1N1 viruses are sensitive to neuraminidase inhibitors (oseltamivir). However, current less virulent S-OIV may evolve into a pathogenic strain or acquire antiviral resistance, potentially with more severe clinical consequences. Efforts to control these outbreaks would be based on our understanding of novel S-OIV and previous influenza pandemics.

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

• 대한한방내과학회지
• /
• 제30권3호
• /
• pp.558-570
• /
• 2009

Background : Since March 2009, when the first patient of novel influenza A (H1N1) was reported, many deaths have occurred in North and Central America. The start of the 2009 influenza pandemic was declared by WHO Director-General Dr. Margaret Chan on 11 June 2009, and the level of influenza pandemic alert raised from phase 5 to phase 6. There was no vaccine yet developed, and many experts worried that the novel H1N1 virus could kill as many or more as did the influenza pandemic in 1918-1919. Objective : To evaluate the possibility of treatment for 2009 novel influenza A (H1N1) using herbal remedies and other non-conventional therapies. Methods : We researched the clinical studies for novel H1N1 influenza virus-related herbal medicine or non-conventional medicine treatment using internet search engines including PubMed and CNKI. In addition, we reviewed many reports and clinical practice guidelines (CPG) for influenza A (H1N1). Results : Two case series were selected after reviewing 701 papers, and two CPG published by the Chinese government and Jilin province identified. They reported that the clinical symptoms were no more significant than seasonal influenza, and the condition of patients more than 45 years old was milder than those less than 45 years old. There are no patients with gastric problems, and oseltamivir has been used at the same time in all patients. Conclusion : The efficacy and effectiveness of herbal medicine and other non-conventional treatments for the novel influenza A (H1N1) is questionable, and more studies are needed to draw a firm conclusion. However, in the severe acute respiratory syndrome (SARS) experience in 2002/2003, it was demonstrated that herbal medicine can relieve all symptoms of SARS patients, promote absorption of lung inflammation, improve the degree of blood oxygen saturation, regulate immunological functions, reduce the required dosage of glucocorticoid and other medicines, and reduce case fatality rate. In light of the current situation that there is no vaccine or conventional treatment yet available, the study of herbal medicine and other non-conventional therapies are also necessary for appropriate evaluation.

• Journal of Microbiology and Biotechnology
• /
• 제20권10호
• /
• pp.1450-1456
• /
• 2010

Accurate and rapid diagnosis of Pandemic Influenza A/H1N1 2009 virus (H1N1 2009) infection is important for the prevention and control of influenza epidemics and the timely initiation of antiviral treatment. This study was conducted to evaluate the performance of several diagnostic tools for the detection of H1N1 2009. Flocked nasopharyngeal swabs were collected from 254 outpatients of suspected H1N1 2009 during October 2009. This study analyzed the performances of the RealTime Ready Inf A/H1N1 Detection Set (Roche), Influenza A (H1N1) Real-Time Detection Kit (Bionote), Seeplex Influenza A/B OneStep Typing Set [Seeplex Reverse Transcriptase PCR (RT-PCR)], BinaxNow Influenza A & B Test Kit [Binax Rapid Antigen Test (RAT)], and SD BIOLINE Influenza Ag kit (SD RAT). Roche and Bionote real-time RT-PCR showed identical results for the H1N1 2009 hemagglutinin gene. Compared with real-time RT-PCR, the sensitivities and specificities were 83.7% and 100% for Seeplex RT-PCR, 64.5% and 94.7% for Binax RAT, and 69.5% and 100% for SD RAT. The sensitivities of Seeplex RT-PCR, Binax RAT, and SD RAT in patients aged over 21 years were 73.7%, 47.4%, and 57.9%, respectively. The sensitivities of Seeplex RT-PCR, Binax RAT, and SD RAT on the day of initial symptoms were mostly lower (68.8%, 56.3%, and 31.3%, respectively). In conclusion, multiplex RT-PCR and RAT for the detection of H1N1 2009 were significantly less sensitive than real-time RT-PCR. Moreover, a negative RAT may require more sensitive confirmatory assays, because it cannot be ruled out from influenza infection.

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

• Journal of Yeungnam Medical Science
• /
• 제27권1호
• /
• pp.18-26
• /
• 2010

The clinical picture in severe cases of pandemic (H1N1) 2009 influenza is markedly different from the disease pattern seen during the epidemics of seasonal influenza as many of those affected were previously healthy young people. Current predictions estimate that during a pandemic wave, 12~30% of the population will develop clinical influenza (compared with 5~15% for seasonal influenza) with 4% of those patients requiring hospital admissions and one in five requiring critical care. Until July 6, 94,512 people have been infected in 122 countries, of whom 429 have died with an overall case-fatality rate of <0.5%. Most of the confirmed cases of S-OIV (Swine-Origin Influenza A Virus) infection have been characterized by a self-limited, uncomplicated febrile respiratory illness and 38% of the cases have also included vomiting or diarrhea. Efforts to control these outbreaks are based on our understanding of novel S-OIV (Swine-Origin Influenza A Virus) and the previous influenza pandemics. So, this review covers the experience with S-OIV (Swine-Origin Influenza A Virus) for the admission and background data and the clinical presentation, diagnosis and treatment of H1N1 in pediatric patient with S-OIV (Swine-Origin Influenza A Virus) at YUMC, 2009.

• Pediatric Infection and Vaccine
• /
• 제19권1호
• /
• pp.1-11
• /
• 2012

목 적 : 인플루엔자는 소아암 환자에게 이환율과 사망률이 높은 질환이나 소아암 환자에 대한 예방 접종률은 낮은 상태이다. 본 연구에서는 소아암 환자를 대상으로 인플루엔자 예방접종의 면역원성과 부작용에 대한 평가를 시행하였다. 방 법 : 2009년 10월부터 12월까지 원자력의학원에서 인플루엔자 예방접종(SK influenza IX vaccine$^{(R)}$)을 받은 25명의 소아암 환자를 대상으로 연구를 시행했다. 예방접종일과 접종 후 30일 뒤 2회에 걸쳐 채혈하였고 혈구응집억제 항체가를 측정하였다. 백신의 면역원성은 접종 전과 접종 후 30일의 혈구응집억제 항체가 1:40 이상인 피험자 비율, 접종 후 30일의 항체 양전율, 접종 전과 접종 후 30일 사이의 GMT 증가 배수로 평가하였다. 결 과 : 본 연구대상자 중에서 심각한 예방접종관련 부작용을 경험한 대상자는 없었다. 접종 후 혈구응집억제 항체가 1:40 이상을 보인 피험자의 비율은 H1N1 항원에 대해 68%, H3N2 항원에 대해 40%, B 항원에 대해 36%였다. 항체양전율은 H1N1 항원에 대해 12%, H3N2 항원에 대해 16%, B 항원에 대해 20%였다. GMT 증가 배수는 H1N1 항원에 대해 0.9, H3N2 항원에 대해 1.2, B 항원에 대해 1.8이었다. 결 론 : 본 연구의 대상자들은 인플루엔자 백신에 대해 제한적인 면역반응을 보였으나 일부 대상자들에게서 항체 양전이 나타났고 심각한 예방접종관련 부작용이 없었던 점을 고려할 때 소아암환자를 대상으로 매년 정기적인 인플루엔자 예방접종이 추천된다.

• 한국동물위생학회지
• /
• 제34권3호
• /
• pp.195-200
• /
• 2011

Swine influenza is an acute respiratory disease prevalent in pig-growing areas all around the world and plays the roles of an intermediate host to be transmitted to mammals including human beings through a genetic recombination with the avian influenza virus. Recognizing that people could be contracted with swine influenza, this study set out to investigate the seroprevalence of individual and multiple infections with two subtypes (H1N1 and H3N2) of the swine influenza virus in pig farms in the Gyeongnam region according to age, area, and season, as well as to provide basic data for the prevention and control of swine influenza. Used in the study were total 904 swine sera that were not vaccinated against the influenza gathered from the pig farms in the Gyeongnam region from November, 2009 to October, 2010. HerdChek SIV (H1N1, H3N2) ELISA kit (IDEXX Laboratories, USA) was used for antibody testing against swine influenza. The test results show that 370 sera (40.9%) were infected with either H1N1 or H3N2 with 37.3% (337 sera) being contracted with H1N1, 13.1% (118 sera) with H3N2, and 9.4% (85) with both H1N1 and H3N2.

• Journal of Preventive Medicine and Public Health
• /
• 제52권5호
• /
• pp.308-315
• /
• 2019

Objectives: Estimating influenza-associated mortality is important since seasonal influenza affects persons of all ages, causing severe illness or death. This study aimed to estimate influenza-associated mortality, considering both periodic changes and age-specific mortality by influenza subtypes. Methods: Using the Microdata Integrated Service from Statistics Korea, we collected weekly mortality data including cause of death. Laboratory surveillance data of respiratory viruses from 2009 to 2016 were obtained from the Korea Centers for Disease Control and Prevention. After adjusting for the annual age-specific population size, we used a negative binomial regression model by age group and influenza subtype. Results: Overall, 1 859 890 deaths were observed and the average rate of influenza virus positivity was 14.7% (standard deviation [SD], 5.8), with the following subtype distribution: A(H1N1), 5.0% (SD, 5.8); A(H3N2), 4.4% (SD, 3.4); and B, 5.3% (SD, 3.7). As a result, among individuals under 65 years old, 6774 (0.51%) all-cause deaths, 2521 (3.05%) respiratory or circulatory deaths, and 1048 (18.23%) influenza or pneumonia deaths were estimated. Among those 65 years of age or older, 30 414 (2.27%) all-cause deaths, 16 411 (3.42%) respiratory or circulatory deaths, and 4906 (6.87%) influenza or pneumonia deaths were estimated. Influenza A(H3N2) virus was the major contributor to influenza-associated all-cause and respiratory or circulatory deaths in both age groups. However, influenza A(H1N1) virus-associated influenza or pneumonia deaths were more common in those under 65 years old. Conclusions: Influenza-associated mortality was substantial during this period, especially in the elderly. By subtype, influenza A(H3N2) virus made the largest contribution to influenza-associated mortality.

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