甲型H5N1和H7N9禽流感——关注2013年H7N9禽流感疫情

禽流感病毒可以感染人类,通常病情轻微,1997年出现的H5N1禽流感和本年初出现的H7N9禽流感病情严重,病死率高。青少年和儿童H5N1禽流感病死率低于成人,年龄越小,病死率越低。有限的儿童病例经治疗迅速康复,以及儿童携带者的发现提示儿童H7N9禽流感病情轻微。禽流感治疗强调尽早使用奥司他韦进行抗病毒治疗,重症者需积极的呼吸支持、循环支持和抑制免疫反应等综合治疗。     

2009甲型H1N1流感研究进展

2009年3月在墨西哥出现了一种新型甲型H1N1流感病毒,这是一个四源重排的A型流感病毒:来源于猪流感病毒、禽流感病毒及人流感病毒.其临床特点与季节性流感相似,但重症病例可发生在无基础疾病的青壮年人,这与季节性流感不同,其高危人群为患有基础疾病者、孕妇及肥胖者.尽管已经出现了耐药毒株,但奥司他韦治疗仍然有效.该文主要对2009年流行的甲型H1N1流感病毒的基因特点、临床表现及治疗的最新进展进行综述.     

甲型H1N1流感的研究进展

甲型H1N1流感病毒是人流感病毒基因、禽流感病毒基因和猪流感病毒基因混合的重配株,其造成的疫情来势凶猛,引起世界各国的广泛关注.为了早发现、早诊断、早治疗及有效地预防甲型H1N1流感,本文综述了甲型H1N1流感病毒的特点、流行病学、致人发病的机制、甲型H1N1流感患者的临床表现、实验室检查及有效的治疗和预防措施.     

The first case of H5N1 avian influenza infection in a human with complications of adult respiratory distress syndrome and Reye's syndrome

Avian influenza virus was not known to cause systemic infection in humans before. We report a 3-year-old boy with good past health who developed pneumonia caused by H5N1 avian influenza A virus (A/Hong Kong/156/97). The virus was isolated from a tracheal aspirate. There were complications of Reye's syndrome, adult respiratory distress syndrome, and multiple organ system failure. He had a history of receiving aspirin. His adult respiratory distress syndrome did not respond to endotracheal surfactant replacement therapy. He died 6 days after admission. Clinicians should be alert to the importance of a new human influenza strain.     

甲型H7N9禽流感病毒的病毒学特征

自2013年2月开始,中国东部省市陆续新发现了由甲型H7N9禽流感病毒引起人感染的病例。研究表明甲型H7N9病毒是一个单纯禽类来源的三元重配体,它的HA和PB2蛋白存在多个特征性突变（包括G186V、Q226L和E627K氨基酸替换）,这些突变可能促进了该病毒与人细胞受体的结合以及病毒的复制。目前尚未发现H7N9禽流感病毒发生稳定的人与人间的传播,但不能排除有限人传人的可能。应加强对H7N9病毒的监测,进一步了解该病毒的来源、传播以及可能造成的威胁。     

中国大陆首例H5N1人禽流感肺炎报告

目的总结2005年中国首例确诊并救治成功的人禽流感肺炎病例的临床特征、诊疗经验。方法分析我院收治抢救的中国大陆首例人禽流感肺炎病例的临床资料,总结其临床特点、诊疗体会。结果本例为9岁男孩,急性起病,但早期症状与普通呼吸道感染相似,早期症状轻,表现为发热、干咳,卡他症状不明显,容易被忽视而耽误治疗;5~7 d进入进展期后,有进展快,肺部改变严重及血象白细胞低的特点。本例初期体温中度升高,能坚持上学;病程第7天病情加重,体温高,达40℃,精神差,伴气促,肺部湿啰音明显,胸片双肺呈现大片致密影,周围血象低,白细胞最低为2.81×109/L,分类以中性核粒细胞为主。给予抗病毒和糖皮质激素等综合治疗,体温在入院后第3天降至正常,胸片于第5天开始吸收,血白细胞于第6天恢复正常。未出现特殊并发症。在病程中早期禽流感病毒(H5N1)核酸检测阴性,通过恢复期血清抗体4倍升高而确诊。本例没有使用达菲,服用金刚烷胺、利巴韦林5 d,同时采取抗感染和小剂量糖皮质激素3周等综合治疗痊愈出院。结论早期重视流行病学调查,可以达到人禽流感肺炎的早发现和早诊断,应用有效治疗可控制病情和改善预后。     

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??Objective To summarize and analyze the clinical characteristics?? diagnostic and therapeutic measures for the first child case of severe H5N6 avian influenza pneumonia in China. Methods The clinical data of the first case of severe H5N6 avian influenza infection in China admitted in April 13?? 2016 in Department of Emergency Center?? Hunan Children’s Hospital were analyzed and summarized. Results The case was an 11 years old girl?? acute onset?? was similar with early symptoms of common respiratory infection including high fever?? fatigue?? vomiting?? but catarrhal symptoms was not obvious. Since fever of unknown origin?? obvious weakness?? vomiting and other suspected influenza symptoms??clinicians speculated “flu” or “bird flu” possibility considering her history of exposure to her mother died of unknown illness. The girl was admitted to the Department of Infectious Isolation Ward and received oral oseltamivir treatment. On the 8th day of the course?? the condition was aggravated?? which showed large areas of dense shadow on chest X-ray film.The girl was diagnosed as acute respiratory distress syndrome??ARDS???? and was transferred to the Intensive Care Unit for isolation and treatment. Based on the reports of Hunan CDC and National CDC?? the girl was confirmed to be a case of avian influenza A H5N6 virus infection case. The treatment started with oseltamivir and then peramivir antivirus treatmnet?? nCPAP ventilation?? synchronous glucocorticoid treatment?? and the gradual weaning of noninvasive ventilator. The girl recovered and was tolerance without oxygen therapy?? then discharged from hospital. Conclusion It is very important for clinicians to pay more attention to epidemiological history. Timely detection?? early diagnosis are crucial to the treatment of avian influenza virus pneumonia and the effective treatment can get better prognosis.     

Human swine influenza A [H1N1]: Practical advice for clinicians early in the pandemic

The influenza pandemic the world was waiting for may have arrived, but the early indications are that the first wave of human swine influenza A [H1N1], also referred to as H1N1 Mexico 09 or “swine flu”, is highly transmissible but of no greater virulence than seasonal influenza to date. The new swine flu H1N1 virus is a mixture of avian, porcine and human influenza RNA. With twenty thousand confirmed cases worldwide and 117 deaths within 7 weeks of the first acknowledgement of a possible pandemic by Mexican and WHO experts, the mortality rate is less than 0.1% and the majority of deaths centred upon the origin of the epidemic in Mexico [83%]. Swine flu is thus far a relatively mild illness seen predominantly in those who are healthy and under 25 years of age, perhaps reflecting protection from previous human influenza exposure in older people. As the virus spreads internationally, border protection issues have surfaced and public health initiatives are being progressively rolled out to minimise the transmission. Vaccines are being developed which will be trialled in the coming months with a likely availability by August 2009, in time for the northern hemisphere autumn and winter. Vigilance without alarm appears to be the recommendation so far.     

Placental transmission of novel pandemic influenza a virus

The effects of maternal influenza on the fetus are not well understood. Viremia is believed to occur infrequently and thus vertical transmission appears to be rare. Highly pathogenic strains of influenza virus, such as avian influenza A (H5N1), are more likely to be transmitted across the placenta. Placental tissues of seven women with confirmed H1N1 infection were examined molecularly with RT-PCR and microscopically to investigate whether H1N1 virus vertically transmitted. We found no evidence for placental transmission of H1N1 virus in this study. In the absence of vertical transmission, adverse effects like neonatal seizures, encephalopathy, cerebral palsy, and even neonatal death can still occur. Since a significant knowledge gap exists for the effects of this novel virus on the fetus, further studies will be beneficial.     

流感病毒与肺炎链球菌相互作用的机制

流感死亡病例多与继发细菌感染,尤其是肺炎链球菌感染有关.病毒感染损伤正常保护性上皮层,引起小气道阻塞等呼吸道功能改变,有利于细菌定植和繁殖.流感病毒感染后的免疫反应也有利于继发细菌感染.细菌可增强病毒的致病力,细菌产生的蛋白酶可以裂解活化病毒血凝素的糖蛋白,使其获得感染力.细菌感染与原发流感病毒感染同时存在的患者症状严...     

Rhabdomyolysis associated with influenza A/H1N1 2009 infection in a pediatric patient

The influenza A/H1N1 2009 epidemic has spread to many countries since 2009, including Japan. We report an immune‐competent child involving rhabdomyolysis and compartment syndrome associated with influenza A/H1N1 2009. The patient was demonstrated rhabdomyolysis with myoglobinuria, hyperkalemia, cardiac dysfunction and compartment syndrome that arose during convalescence from influenza A/H1N1 2009 infection. Although RT‐PCR of muscle tissue yielded negative results for influenza A/H1N1 2009 RNA and no viral positive‐antigen cells were detected in the muscle lesions, the clinical picture suggested rhabdomyolysis associated with influenza A/H1N1. Rhabdomyolysis should be considered in the evaluation of muscle symptoms such as myalgia associated with novel influenza A/H1N1 2009 virus infection, particularly in critically ill patients.     

A severely immunocompromised child with uncomplicated oseltamivir-resistant 2009 H1N1 pandemic influenza infection

2009 H1N1 pandemic influenza was associated with increased risk for severe disease in children and the immunosuppressed. We report a case of uncomplicated pneumonia because of infection with oseltamivir-resistant 2009 H1N1 virus in an immunosuppressed pediatric renal transplant patient. Innate immunity and/or altered viral fitness may be responsible for the mild clinical phenotype of the case.     

An influenza Epidemic among Institutionalized Children at the Time of Replacement from A(H3N2)to A(H1N1): Observation of 32 Cases Including 3 Cases of Probable Simultaneous Infection with A(H1N1) and A(H3N2)

An influenza epidemic occurred in Fukuoka, southern part of Japan in January, 1978 in which both influenza virus A(H1N1) and A (H3N2) were isolated. Thirty-two institutionalized children with influenza were studied at the time of this shift from A (H3N2) to A (H1N1). Fourteen virus strains were isolated. Thirteen strains belonged to influenza virus A (H1N1) (A/USSR/92/77-like strain) and one a mixed strain of A (H1N1) and A (H3N2) (A/Texas/77-like strain). The hemagglutination inhibition (H1)tests of paired sera indicated that of the 32 Children, 27 Showed a significant increasein HI antibody titers for influenza virus A (H1N1). 2 for A (H3N2) and the remaining 3, including the case from which the mixed virus strain was isolated, for both A (H1N1) and A (H3N2). These offers 3 cases were thought to be probably infected simulataneously with both influenza virus A (H1N1) and A (H3N2). Clinical manifestations due to influenza virus A (H1N1) were moderate and the 3 cases of probable simultaneous infection with both influenza virus A (H1N1) and A (H3N2) did not show two clinical episodes but rather a single episode with clinical manifestations similar to the cases with single virus infection.     

Antiviral therapy and prophylaxis for influenza in children

Antiviral agents are available that are safe and effective for the treatment and prophylaxis of influenza virus infections in children. The neuraminidase inhibitors (oseltamivir [Tamiflu] and zanamivir [Relenza]) are preferred agents because of current widespread resistance to the adamantanes (amantadine [Symmetrel] and rimantadine [Flumadine]). Therapy should be provided to children with influenza infection who are at high risk of severe infection and to children with moderate-to-severe influenza infection who may benefit from a decrease in the duration of symptoms. Prophylaxis should be provided (1) to high-risk children who have not yet received immunization and during the 2 weeks after immunization, (2) to unimmunized family members and health care professionals with close contact with high-risk unimmunized children or infants who are younger than 6 months, and (3) for control of influenza outbreaks in unimmunized staff and children in an institutional setting. Testing of current H5N1 avian influenza virus isolates, the potential agents of pandemic influenza, suggests susceptibility to oseltamivir and zanamivir. Because no prospective data exist on the efficacy of these agents in humans for H5N1 strains, the dosage and duration of therapy in adults and children may differ from those documented to be effective for epidemic influenza strains.     

Comparison of influenza A and influenza B virus infection in hospitalized children

BACKGROUND: Influenza A and B viruses were cocirculating in Australia in the winter of 1997. Objective: To compare the clinical and demographic features of children with influenza A or influenza B virus infection admitted to a paediatric tertiary referral centre. METHODOLOGY: Retrospective chart review of 91 hospitalized children with culture-proven influenza A or B virus infection during 1997. RESULTS: Thirty-six (56%) of 64 children with influenza A were under 12 months of age compared with seven (26%) of 27 children with influenza B virus infection (P = 0.02). Influenza B virus infection was more common in children with underlying medical problems (P = 0. 01). Neurological manifestations were present in eight (12.5%) of 64 children with influenza A and none with influenza B virus infection (P = 0.09). There were no significant differences in signs and symptoms of children with influenza A and B virus infection, in severity of illness or in duration of hospital stay. CONCLUSIONS: A greater proportion of children admitted with influenza A virus infection were under 12 months of age. Influenza B virus infection is associated more commonly with underlying medical disorders. It is not possible to differentiate between influenza A or B virus infection from presenting clinical signs and symptoms.     

Influenza A virus encephalopathy with symmetrical thalamic lesions

 During an epidemic of influenza A infection in Japan, a 7-year-old boy was admitted to our hospital because of high fever, convulsions, coma, and liver dysfunction on the 2nd day of a cold-like illness. His serum CPK was markedly elevated, but there was no hyperammonaemia or hypoglycaemia. His CSF showed an increased protein level, but the cell count and glucose level were normal. CT and MRI of the brain showed symmetrical thalamic lesions, and he was diagnosed with acute necrotizing encephalopathy in childhood. He had a significant increased in antibodies to influenza A H1N1 in serum and CSF, but the CSF was negative for influenza virus using virus isolation and a polymerase chain reaction assay. Conclusion Antibody production without detectable levels of influenza virus in cerebrospinal fluid suggests that virus infection occurred, but the virus did not replicate in sufficient numbers in his central nervous system. The thalamic lesion, the hallmark of acute necrotizing encephalopathy in childhood, may be initiated by a local virus infection and develop with subsequent local changes such as breakdown of the blood-brain barrier and the extravasation of blood. Received: 30 March 1999 and in revised form: 1 October 1999 / Accepted: 1 October 1999     

流感病毒抗原消失时间探讨

目的通过免疫荧光抗原检测技术动态监测流感患儿流感病毒抗原,观察患儿抗原转阴时间和临床症状消失时间,以及两者之间的关系。方法对2016年3~4月就诊于湖南省人民医院的1 063例疑似流感患儿运用甲乙型流感病毒抗原检测试剂盒(免疫荧光法)行流感病毒抗原检测,阳性者予以奥司他韦抗病毒治疗;并嘱咐患者起病后5 d内、5~7 d及7 d后3个时间段复查流感病毒抗原。结果 1 063例疑似流感病例中,流感病毒检出560例(52.68%)。对215例流感病毒阳性患儿进行随访,起病5 d内流感病毒抗原转阴率为9.8%(21例),5~7 d内累积转阴率为32.1%(69例),7~10 d累积转阴率为98.1%(211例);起病3 d内临床症状改善率为2.8%(6例),3~5 d临床症状改善累积率为84.7%(182例),5 d后所有患儿临床症状均得到改善。结论流感患儿经治疗临床症状改善时间早于抗原消失时间;起病7~10 d后流感病毒抗原近100%转阴,推测患儿在起病7~10 d、临床症状消失后返校是相对安全的。     

Fatal influenza A virus infection in a child vaccinated against influenza

We report a fatal infection with influenza A virus in a 13-year-old child who had been vaccinated against influenza. Influenza A virus RNA was detected by PCR in lungs, bronchi and myocardium. A penicillin-sensitive strain of Staphylococcus aureus was also isolated from her bronchi. This case indicates that a primary viral pneumonia with influenza A virus complicated by a bacterial superinfection with S. aureus can run a fatal course even in a vaccinated child.