Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.
Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon; Université des Sciences de la Santé de Libreville, Libreville, Gabon.
Int J Infect Dis. 2020 Feb;91:129-136. doi: 10.1016/j.ijid.2019.12.002. Epub 2019 Dec 7.
Dengue outbreaks, mainly caused by dengue virus serotype 2 (DENV-2), occurred in 2007 and in 2010 in Gabon, Central Africa. However, information on DENV infections has been insufficient since 2010. The aim of this study was to investigate the current DENV infection scenario and the risk of repeated infections in Gabon.
During 2015-2017, serum samples were collected from enrolled febrile participants and were tested for DENV infection using RT-qPCR. DENV-positive samples were analyzed for a history of previous DENV infection(s) using ELISA. The complete DENV genome was sequenced to analyze the phylogeny of Gabonese DENV strains.
DENV-3 was exclusively detected, with a high rate of anti-DENV IgG seropositivity among DENV-3-positive participants. DENV-3 showed higher infection rates in adults and the infection was seasonal with peaks in the rainy seasons. Phylogenetic analysis revealed that Gabonese DENV-3 originated from West African strains and has been circulating continuously in Gabon since at least 2010, when the first DENV-3 case was reported.
These findings indicate stable DENV-3 circulation and the risk of repeated DENV infections in Gabon, highlighting the need for continuous monitoring to control DENV infections.
2007 年和 2010 年，中非国家加蓬暴发了主要由登革病毒血清型 2（DENV-2）引起的登革热疫情。然而，自 2010 年以来，有关 DENV 感染的信息一直不足。本研究旨在调查加蓬目前的 DENV 感染情况和重复感染的风险。
在 2015 年至 2017 年期间，采集了入组发热参与者的血清样本，并使用 RT-qPCR 检测 DENV 感染情况。使用 ELISA 分析 DENV 阳性样本，以了解先前 DENV 感染的情况。对完整的 DENV 基因组进行测序，以分析加蓬 DENV 株的系统发育。
仅检测到 DENV-3，DENV-3 阳性参与者的抗 DENV IgG 血清阳性率很高。DENV-3 在成年人中的感染率较高，且具有季节性，雨季时达到高峰。系统发育分析表明，加蓬的 DENV-3 源自西非株，自 2010 年首次报告 DENV-3 病例以来，一直在加蓬持续传播。
这些发现表明 DENV-3 持续循环，加蓬存在重复感染 DENV 的风险，强调需要持续监测以控制 DENV 感染。
