Uniformed Services University of the Health Sciences, Bethesda, Maryland.
Brooke Army Medical Center, Fort Sam Houston, Texas.
Am J Trop Med Hyg. 2020 Apr;102(4):821-826. doi: 10.4269/ajtmh.19-0648.
Travelers are often at risk for both influenza-like illness (ILI) and malaria. Doxycycline is active against pathogens causing ILI and is used for malaria prophylaxis. We evaluated the risk factors for ILI, and whether the choice of malaria prophylaxis was associated with ILI. TravMil is a prospective observational study enrolling subjects presenting to military travel clinics. Influenza-like illness was defined as subjective fever with either a sore throat or cough. Characteristics of trip and use of malaria prophylaxis were analyzed to determine association with development of ILI. Poisson regression models with robust error variance were used to estimate relative risk (RR) of ILI. A total of 3,227 trips were enrolled: 62.1% male, median age of 39 years (interquartile range [IQR] 27,59), median travel duration 19 days (IQR 12, 49); 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean and Latin America. Military travel (46%) and vacation (40%) were most common reasons for travel. Among them, 20% took doxycycline, 50% other prophylaxis, and 30% took none; 8.7% developed ILI. Decreased RR of ILI was associated with doxycycline (RR 0.65 [0.43-0.99], = 0.046) and military travel (RR 0.30 [0.21-0.43], < 0.01). Increased risk of ILI was associated with female gender (RR 1.57 [1.24-1.98], < 0.01), travel to Asia (RR 1.37 [1.08-1.75], = 0.01), and cruises (RR 2.21 [1.73-2.83], < 0.01). Use of doxycycline malaria prophylaxis is associated with a decreased risk of ILI. Possible reasons include anti-inflammatory or antimicrobial effects, or other unmeasured factors. With few strategies for decreasing ILI in travelers, these findings bear further investigation.
旅行者常面临流感样疾病（ILI）和疟疾的风险。多西环素对引起 ILI 的病原体具有活性，用于疟疾预防。我们评估了 ILI 的危险因素，以及疟疾预防的选择是否与 ILI 相关。TravMil 是一项前瞻性观察性研究，纳入了就诊于军事旅行诊所的受试者。ILI 定义为有咽痛或咳嗽的主观发热。分析旅行特征和疟疾预防的使用情况，以确定与 ILI 发病的关系。采用具有稳健误差方差的泊松回归模型来估计 ILI 的相对风险（RR）。共纳入 3227 次旅行：62.1%为男性，中位年龄 39 岁（四分位距[IQR]27,59），中位旅行时间 19 天（IQR12,49）；32%前往非洲，40%前往亚洲，27%前往加勒比和拉丁美洲。军事旅行（46%）和休假（40%）是旅行的最常见原因。其中，20%服用多西环素，50%服用其他预防药物，30%未服用任何药物；8.7%发生 ILI。服用多西环素（RR0.65[0.43-0.99]， = 0.046）和军事旅行（RR0.30[0.21-0.43]， < 0.01）与 ILI 的 RR 降低相关。女性（RR1.57[1.24-1.98]， < 0.01）、前往亚洲（RR1.37[1.08-1.75]， = 0.01）和乘船旅行（RR2.21[1.73-2.83]， < 0.01）与 ILI 风险增加相关。使用多西环素疟疾预防与 ILI 风险降低相关。可能的原因包括抗炎或抗菌作用，或其他未测量的因素。由于旅行者中减少 ILI 的策略很少，这些发现值得进一步研究。
