Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK.
J Travel Med. 2019 Oct 14;26(7). doi: 10.1093/jtm/taz062.
Dengue is a frequent cause of febrile illness among travellers and has overtaken malaria as the leading cause of febrile illness for those traveling to Southeast Asia. The purpose is to review the risk of dengue and severe dengue in travellers with a particular focus on the pathogenesis and clinical management of severe dengue.
RISK, PATHOGENESIS AND CLINICAL MANAGEMENT: The risk of travel-acquired dengue depends on destination, season and duration of travel and activities during travel. Seroconversion rates reported in travellers, therefore, vary between <1% and >20%. The most common life-threatening clinical response to dengue infection is the dengue vascular permeability syndrome, epidemiologically linked to secondary infection, but can also occur in primary infection. Tertiary and quaternary infections are usually associated with mild or no disease. Antibody-dependent enhancement, viral factors, age, host factors and clinical experience of the managing physician modulate the risk of progressing to severe dengue. The relative risk of severe dengue in secondary versus primary infection ranges from 2 to 7. The absolute risk of severe dengue in children in highly endemic areas is ~0.1% per year for primary infections and 0.4% for secondary infections. About 2-4% of secondary infections lead to severe dengue. Severe dengue and death are both relatively rare in general travellers but more frequently in those visiting friends and relatives. Clinical management of severe dengue depends on judicious use of fluid rehydration.
Although dengue is a frequent cause of travel illness, severe dengue and deaths are rare. Nevertheless, dengue infections can interrupt travel and lead to evacuation and major out-of-pocket costs. Dengue is more frequent than many other travel-related vaccine preventable diseases, such as hepatitis A, hepatitis B, rabies, Japanese encephalitis and yellow fever, indicating a need for a dengue vaccine for travellers.
登革热是旅行者发热的常见病因，且已取代疟疾，成为东南亚旅行者发热的首要病因。本综述旨在阐述旅行者感染登革热及重症登革热的风险，并特别关注重症登革热的发病机制和临床管理。
风险、发病机制和临床管理：旅行者发生输入性登革热的风险取决于旅行目的地、旅行季节、旅行时长及旅行期间的活动。因此，旅行者的血清转化率报道值在＜1%至＞20%之间变化。登革热感染后，最常见的危及生命的临床反应为登革出血热，与二次感染相关，但也可能发生于初次感染。三次和四次感染通常与轻度或无疾病相关。抗体依赖性增强作用、病毒因素、年龄、宿主因素和主治医生的临床经验可调节进展为重症登革热的风险。与初次感染相比，二次感染发展为重症登革热的相对风险范围为 2 至 7。在高度流行地区，儿童初次感染的重症登革热绝对风险约为每年 0.1%，二次感染的绝对风险约为 0.4%。约 2-4%的二次感染会导致重症登革热。总体旅行者中重症登革热和死亡均相对罕见，但在探亲访友旅行者中更常见。重症登革热的临床管理取决于合理使用液体复苏。
尽管登革热是旅行疾病的常见病因，但重症登革热和死亡仍较为罕见。尽管如此，登革热感染可导致旅行者中断旅行并引发遣返和大额自付费用。与其他许多旅行相关的可预防疫苗疾病（如甲型肝炎、乙型肝炎、狂犬病、日本脑炎和黄热病）相比，登革热更为常见，表明旅行者需要登革热疫苗。
