Department of Emerging Infectious Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.
Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.
BMC Infect Dis. 2021 Mar 17;21(1):265. doi: 10.1186/s12879-021-05960-9.
Increasing arbovirus infections have been a global burden in recent decades. Many countries have experienced the periodic emergence of arbovirus diseases. However, information on the prevalence of arboviruses is largely unknown or infrequently updated because of the lack of surveillance studies, especially in Africa.
A surveillance study was conducted in Gabon, Central Africa, on arboviruses, which are a major public health concern in Africa, including: West Nile virus (WNV), dengue virus (DENV), Zika virus (ZIKV), yellow fever virus (YFV), chikungunya virus (CHIKV), and Rift Valley fever virus (RVFV). Serological and molecular assays were performed to investigate past infection history and the current status of infection, using serum samples collected from healthy individuals and febrile patients, respectively.
The overall seroprevalence during 2014-2017 was estimated to be 25.3% for WNV, 20.4% for DENV, 40.3% for ZIKV, 60.7% for YFV, 61.2% for CHIKV, and 14.3% for RVFV. No significant differences were found in the seroprevalence of any of the viruses between the male and female populations. However, a focus on the mean age in each arbovirus-seropositive individual showed a significantly younger age in WNV- and DENV-seropositive individuals than in CHIKV-seropositive individuals, indicating that WNV and DENV caused a relatively recent epidemic in the region, whereas CHIKV had actively circulated before. Of note, this indication was supported by the detection of both WNV and DENV genomes in serum samples collected from febrile patients after 2016.
This study revealed the recent re-emergence of WNV and DENV in Gabon as well as the latest seroprevalence state of the major arboviruses, which indicated the different potential risks of virus infections and virus-specific circulation patterns. This information will be helpful for public health organizations and will enable a rapid response towards these arbovirus infections, thereby preventing future spread in the country.
近几十年来，虫媒病毒感染不断增加，成为全球负担。许多国家都经历过虫媒病毒病的周期性出现。然而，由于缺乏监测研究，特别是在非洲，有关虫媒病毒的流行信息在很大程度上是未知的或更新不频繁。
在中非加蓬进行了一项虫媒病毒监测研究，这些病毒是非洲主要的公共卫生关注点，包括：西尼罗河病毒（WNV）、登革热病毒（DENV）、寨卡病毒（ZIKV）、黄热病病毒（YFV）、基孔肯雅热病毒（CHIKV）和裂谷热病毒（RVFV）。使用分别从健康个体和发热患者采集的血清样本，通过血清学和分子检测来调查过去的感染史和当前的感染情况。
2014 年至 2017 年期间，WNV、DENV、ZIKV、YFV、CHIKV 和 RVFV 的总血清阳性率估计分别为 25.3%、20.4%、40.3%、60.7%、61.2%和 14.3%。在男性和女性人群中，任何一种病毒的血清阳性率均无显著差异。然而，对每个虫媒病毒血清阳性个体的平均年龄进行重点关注表明，WNV 和 DENV 血清阳性个体的年龄明显小于 CHIKV 血清阳性个体，这表明 WNV 和 DENV 在该地区引起了相对近期的流行，而 CHIKV 在此之前已经活跃传播。值得注意的是，这一迹象得到了 2016 年后从发热患者采集的血清样本中同时检测到 WNV 和 DENV 基因组的支持。
本研究揭示了 WNV 和 DENV 在加蓬的再次出现以及主要虫媒病毒的最新血清阳性率状况，这表明不同病毒感染的潜在风险和病毒特异性传播模式存在差异。这些信息将有助于公共卫生组织，并使他们能够对这些虫媒病毒感染做出快速反应，从而防止该国有进一步的传播。
