BACKGROUND Human parainfluenza viruses (HPIVs) cause upper and lower respiratory tract illnesses, most frequently among infants and young children, but also in the elderly. While seasonal patterns of HPIV types 1-3 have been described, less is known about national patterns of HPIV-4 circulation. OBJECTIVES To describe patterns of HPIVs circulation in the United States (US). STUDY DESIGN We used data from the National Respiratory and Enteric Virus Surveillance System (NREVSS), a voluntary passive laboratory-based surveillance system, to characterize the epidemiology and circulation patterns of HPIVs in the US during 2011-2019. We summarized the number of weekly aggregated HPIV detections nationally and by US census region, and used a subset of data submitted to NREVSS from public health laboratories and several clinical laboratories during 2015-2019 to analyze differences in patient demographics. RESULTS During July 2011 - June 2019, 2,700,135 HPIV tests were reported; 122,852 (5 %) were positive for any HPIV including 22,446 for HPIV-1 (18 %), 17,474 for HPIV-2 (14 %), 67,649 for HPIV-3 (55 %), and 15,283 for HPIV-4 (13 %). HPIV testing increased substantially each year. The majority of detections occurred in children aged ≤ 2 years (36 %) with fluctuations in the distribution of age by type. CONCLUSIONS HPIVs were detected year-round during 2011-2019, with type-specific year-to-year variations in circulation patterns. Among HPIV detections where age was known, the majority were aged ≤ 2 years. HPIV-4 exhibited an annual fall-winter seasonality, both nationally and regionally. Continued surveillance is needed to better understand national patterns of HPIV circulation.

中文翻译：

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人类副流感病毒传播，美国，2011-2019年。

背景技术人副流感病毒（HPIV）引起上下呼吸道疾病，在婴儿和幼儿中最常见，但在老年人中也最常见。虽然已经描述了1-3型HPIV的季节性模式，但对HPIV-4流通的国家模式知之甚少。目的描述美国（美国）HPIV的传播方式。研究设计我们使用了基于国家被动呼吸和肠道病毒监测系统（NREVSS）的数据，该系统是基于实验室的自愿性被动监测系统，用于表征2011-2019年间美国HPIV的流行病学和流行模式。我们总结了美国和美国人口普查地区每周汇总的HPIV检测数量，并使用了2015-2019年间由公共卫生实验室和几个临床实验室提交给NREVSS的数据子集来分析患者人口统计学差异。结果2011年7月至2019年6月，报告了2700135次HPIV检测；122.852（5％）的任何HPIV阳性，包括HPIV-1的22446（18％），HPIV-2的17474（14％），HPIV-3的67649（55％）和HPIV-4的15283（13％） ）。HPIV测试每年都在大幅增加。大部分检测结果发生在2岁以下的儿童（36％）中，其年龄分布因类型而异。结论HPIVs在2011-2019年间全年被检测到，其流通模式逐年不同。在已知年龄的HPIV检测中，大多数年龄≤2岁。HPIV-4表现出每年的秋冬季节，在国家和地区范围内。需要继续监测以更好地了解HPIV传播的国家模式。