Research Institute for Tropical Medicine, Muntinlupa City, Philippines.
PLoS Negl Trop Dis. 2013 Jul 25;7(7):e2331. doi: 10.1371/journal.pntd.0002331. Print 2013.
Common causes of acute febrile illness in tropical countries have similar symptoms, which often mimic those of dengue. Accurate clinical diagnosis can be difficult without laboratory confirmation and disease burden is generally under-reported. Accurate, population-based, laboratory-confirmed incidence data on dengue and other causes of acute fever in dengue-endemic Asian countries are needed.
This prospective, multicenter, active fever surveillance, cohort study was conducted in selected centers in Indonesia, Malaysia, Philippines, Thailand and Vietnam to determine the incidence density of acute febrile episodes (≥ 38 °C for ≥ 2 days) in 1,500 healthy children aged 2-14 years, followed for a mean 237 days. Causes of fever were assessed by testing acute and convalescent sera from febrile participants for dengue, chikungunya, hepatitis A, influenza A, leptospirosis, rickettsia, and Salmonella Typhi. Overall, 289 participants had acute fever, an incidence density of 33.6 per 100 person-years (95% CI: 30.0; 37.8); 57% were IgM-positive for at least one of these diseases. The most common causes of fever by IgM ELISA were chikungunya (in 35.0% of in febrile participants) and S. Typhi (in 29.4%). The overall incidence density of dengue per 100 person-years was 3.4 by nonstructural protein 1 (NS1) antigen positivity (95% CI: 2.4; 4.8) and 7.3 (95% CI: 5.7; 9.2) by serology. Dengue was diagnosed in 11.4% (95% CI: 8.0; 15.7) and 23.9% (95% CI: 19.1; 29.2) of febrile participants by NS1 positivity and serology, respectively. Of the febrile episodes not clinically diagnosed as dengue, 5.3% were dengue-positive by NS1 antigen testing and 16.0% were dengue-positive by serology.
During the study period, the most common identified causes of pediatric acute febrile illness among the seven tested for were chikungunya, S. Typhi and dengue. Not all dengue cases were clinically diagnosed; laboratory confirmation is essential to refine disease burden estimates.
热带国家中急性发热的常见病因具有相似的症状，常与登革热相似。如果没有实验室确认，准确的临床诊断可能很困难，而且疾病负担通常报告不足。需要在登革热流行的亚洲国家进行准确的、基于人群的、经实验室确认的登革热和其他急性发热病因的发病率数据。
本前瞻性、多中心、主动发热监测队列研究在印度尼西亚、马来西亚、菲律宾、泰国和越南的选定中心进行，旨在确定 1500 名 2-14 岁健康儿童中急性发热发作（≥38°C 持续≥2 天）的发病率密度，平均随访 237 天。通过检测发热参与者的急性和恢复期血清，评估发热原因，检测登革热、基孔肯雅热、甲型肝炎、流感 A、钩端螺旋体病、立克次体和伤寒沙门氏菌。共有 289 名参与者出现急性发热，发病率密度为 33.6/100 人年（95%CI：30.0；37.8）；57%的参与者至少有一种疾病的 IgM 阳性。通过 IgM ELISA 最常见的发热原因是基孔肯雅热（在发热参与者中占 35.0%）和伤寒沙门氏菌（占 29.4%）。非结构蛋白 1（NS1）抗原阳性的登革热总发病率密度为 3.4/100 人年（95%CI：2.4；4.8），血清学为 7.3/100 人年（95%CI：5.7；9.2）。通过 NS1 阳性和血清学，发热参与者中登革热的诊断率分别为 11.4%（95%CI：8.0；15.7）和 23.9%（95%CI：19.1；29.2）。在未经临床诊断为登革热的发热发作中，5.3%通过 NS1 抗原检测呈登革热阳性，16.0%通过血清学呈登革热阳性。
在研究期间，在所检测的七种病因中，小儿急性发热最常见的病因是基孔肯雅热、伤寒沙门氏菌和登革热。并非所有登革热病例都得到临床诊断；实验室确认对于细化疾病负担估计至关重要。
