Abstract Objectives To describe a human metapneumovirus (hMPV) outbreak occurring in a nursing home for older adults and to identify the risk factors associated with the clinical infection. Design A retrospective, case-controlled study. Setting and participants A French nursing home for older adults between December 27, 2014 and January 20, 2015. Probable cases were residents presenting at least 1 respiratory symptom or 1 constitutional symptom. Confirmed cases identified in the same way as probable cases but with a positive RT-PCR test for hMPV. Controls were residents with no symptoms of respiratory infection. Measures Identification of hMPV was realized on nasal swab samples by RT-PCR. Results Seventy-eight older people were resident at the time of the outbreak. Three of the 4 tested were positive for hMPV by RT-PCR and negative for 13 other viruses or bacteria. All probable infected residents presented cough; other symptoms were scarcer. An inflammatory response was present, with median C-reactive protein at 50 mg/L. The median duration of the illness was 7 days. The rate of infection among residents was high (51%), with 5 hospitalizations (12.5%) and 1 death (2.5%). In multivariate analysis, vaccination against influenza virus appeared to emerge as associated with a probable hMPV infection, but this might be an artifact, as the proportion of unvaccinated residents was low (15%). A clear infected population profile was hard to define, although limited autonomy and low ADL score may play a role. Basic hygiene precautions were reinforced, but droplet precautions seemed difficult to apply rigorously to this population. Conclusions/Implications Clinical and biological presentations were nonspecific. The rate of infection was high, highlighting the need for the rapid introduction of strict precautions to contain the infection.

中文翻译：

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疗养院中人偏肺病毒的爆发：临床观点

摘要 目的描述发生在老年人疗养院的人类偏肺病毒 (hMPV) 暴发，并确定与临床感染相关的危险因素。设计 一项回顾性病例对照研究。设置和参与者 2014 年 12 月 27 日至 2015 年 1 月 20 日期间的一家法国老年人疗养院。可能的病例是出现至少 1 种呼吸道症状或 1 种全身症状的居民。确诊病例以与可能病例相同的方式确定，但 hMPV 的 RT-PCR 检测呈阳性。对照是没有呼吸道感染症状的居民。措施 通过RT-PCR 对鼻拭子样本实现hMPV 的鉴定。结果 暴发时有 78 名老年人居住。通过 RT-PCR 检测，4 人中有 3 人对 hMPV 呈阳性，对 13 种其他病毒或细菌呈阴性。所有可能感染的居民都出现咳嗽；其他症状较少。存在炎症反应，中位 C 反应蛋白为 50 mg/L。疾病的中位持续时间为 7 天。居民感染率高（51%），住院5人（12.5%），死亡1人（2.5%）。在多变量分析中，流感病毒疫苗接种似乎与可能的 hMPV 感染有关，但这可能是假象，因为未接种疫苗的居民比例很低 (15%)。尽管有限的自主权和低 ADL 评分可能会起作用，但很难定义明确的感染人群概况。加强了基本的卫生预防措施，但飞沫预防措施似乎难以严格适用于这一人群。结论/意义 临床和生物学表现是非特异性的。感染率很高，突出表明需要迅速采取严格的预防措施来控制感染。