Viral Shedding and Transmission Potential of Asymptomatic and Paucisymptomatic Influenza Virus Infections in the Community
Viral Shedding and Transmission Potential of Asymptomatic and Paucisymptomatic Influenza Virus Infections in the Community
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DOI：
10.1093/cid/ciw841
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发表时间：
2017-03-15
影响因子：
11.8
通讯作者：
Cowling, Benjamin J.
中科院分区：
文献类型：
--
作者：
Ip, Dennis K. M.;Lau, Lincoln L. H.;Cowling, Benjamin J.
背景流感病毒感染与多种疾病有关。然而，很少有研究详细调查的流行病学和病毒学特征的无症状和轻度疾病的流感病毒感染。在2008年至2014年在香港进行的一项以社区为基础的研究中，我们随访了最初健康的个人，这些人是实验室确诊流感症状者的家庭接触者，以确定继发感染。使用每日症状日记中的信息将感染分类为症状性（>= 2种体征/症状，包括发热>= 37.8 ℃、头痛、肌痛、咳嗽、咽喉痛、流鼻涕和痰）、少症状（仅1种症状）或无症状（无这些症状）。我们比较了这两组之间流感病毒脱落的模式。我们在家庭环境中确定了235例病毒学确诊的继发性流感病毒感染病例，包括31例（13%）少症状病例和25例（11%）无症状病例。与有症状的病例相比，少症状和无症状病例的病毒RNA脱落持续时间更短，下降更快。无症状和少症状病例中流感病毒RNA脱落的平均水平比有症状病例低约1-2 log（10）拷贝。在症状很少或没有症状的流感患者中存在流感病毒脱落，反映了他们将病毒传播给密切接触者的可能性。这些发现表明，需要进一步研究，以调查无症状或临床轻度流感病毒感染者在家庭、机构和社区环境中对流感病毒传播的贡献。
Background. Influenza virus infections are associated with a wide spectrum of disease. However, few studies have investigated in detail the epidemiological and virological characteristics of asymptomatic and mild illness with influenza virus infections.Methods. In a community-based study in Hong Kong from 2008 to 2014, we followed up initially healthy individuals who were household contacts of symptomatic persons with laboratory-confirmed influenza, to identify secondary infections. Information from daily symptom diaries was used to classify infections as symptomatic (>= 2 signs/symptoms, including fever >= 37.8 degrees C, headache, myalgia, cough, sore throat, runny nose and sputum), paucisymptomatic (1 symptom only), or asymptomatic (none of these symptoms). We compared the patterns of influenza viral shedding between these groups.Results. We identified 235 virologically confirmed secondary cases of influenza virus infection in the household setting, including 31 (13%) paucisymptomatic and 25 (11%) asymptomatic cases. The duration of viral RNA shedding was shorter and declined more rapidly in paucisymptomatic and asymptomatic than in symptomatic cases. The mean levels of influenza viral RNA shedding in asymptomatic and paucisymptomatic cases were approximately 1-2 log(10) copies lower than in symptomatic cases.Conclusions. The presence of influenza viral shedding in patients with influenza who have very few or no symptoms reflects their potential for transmitting the virus to close contacts. These findings suggest that further research is needed to investigate the contribution of persons with asymptomatic or clinically mild influenza virus infections to influenza virus transmission in household, institutional, and community settings.