Postgraduate Program in Health Sciences, Federal University of Bahia School of Medicine, Salvador, Brazil.
Epidemiology Unit, Health Secretariat, Salvador, Brazil.
Trop Med Int Health. 2021 Jun;26(6):672-679. doi: 10.1111/tmi.13571. Epub 2021 Apr 18.
The frequency and seasonality of viruses in tropical regions are scarcely reported. We estimated the frequency of seven respiratory viruses and assessed seasonality of respiratory syncytial virus (RSV) and influenza viruses in a tropical city.
Children (age ≤ 18 years) with acute respiratory infection were investigated in Salvador, Brazil, between July 2014 and June 2017. Respiratory viruses were searched by direct immunofluorescence and real-time polymerase chain reaction for detection of RSV, influenza A virus, influenza B virus, adenovirus (ADV) and parainfluenza viruses (PIV) 1, 2 and 3. Seasonal distribution was evaluated by Prais-Winsten regression. Due to similar distribution, influenza A and influenza B viruses were grouped to analyse seasonality.
The study group comprised 387 cases whose median (IQR) age was 26.4 (10.5-50.1) months. Respiratory viruses were detected in 106 (27.4%) cases. RSV (n = 76; 19.6%), influenza A virus (n = 11; 2.8%), influenza B virus (n = 7; 1.8%), ADV (n = 5; 1.3%), PIV 1 (n = 5; 1.3%), PIV 3 (n = 3; 0.8%) and PIV 2 (n = 1; 0.3%) were identified. Monthly count of RSV cases demonstrated seasonal distribution (b3 = 0.626; P = 0.003). More than half (42/76 [55.3%]) of all RSV cases were detected from April to June. Monthly count of influenza cases also showed seasonal distribution (b3 = -0.264; P = 0.032). Influenza cases peaked from November to January with 44.4% (8/18) of all influenza cases.
RSV was the most frequently detected virus. RSV and influenza viruses showed seasonal distribution. These data may be useful to plan the best time to carry out prophylaxis and to increase the number of hospital beds.
热带地区病毒的频率和季节性很少有报道。我们估计了七种呼吸道病毒的频率，并评估了热带城市中呼吸道合胞病毒（RSV）和流感病毒的季节性。
2014 年 7 月至 2017 年 6 月，我们在巴西萨尔瓦多调查了患有急性呼吸道感染的儿童（年龄≤18 岁）。通过直接免疫荧光法和实时聚合酶链反应检测 RSV、甲型流感病毒、乙型流感病毒、腺病毒（ADV）和副流感病毒（PIV）1、2 和 3。采用普赖斯-温斯坦回归评估季节性分布。由于分布相似，将甲型流感病毒和乙型流感病毒合并分析季节性。
研究组包括 387 例患者，其中位（IQR）年龄为 26.4（10.5-50.1）个月。106 例（27.4%）患者检测到呼吸道病毒。检测到 76 例 RSV（19.6%）、11 例甲型流感病毒（2.8%）、7 例乙型流感病毒（1.8%）、5 例 ADV（1.3%）、5 例 PIV 1（1.3%）、3 例 PIV 3（0.8%）和 1 例 PIV 2（0.3%）。RSV 病例的月度计数显示季节性分布（b3=0.626；P=0.003）。超过一半（42/76 [55.3%]）的 RSV 病例发生在 4 月至 6 月。流感病例的月度计数也显示季节性分布（b3=-0.264；P=0.032）。流感病例从 11 月到 1 月达到高峰，占所有流感病例的 44.4%（8/18）。
RSV 是最常检测到的病毒。RSV 和流感病毒呈季节性分布。这些数据可能有助于计划最佳的预防时间，并增加医院床位数量。
