Silent Circulation of Dengue Virus in Aedes aegypti Mosquitoes in Non-Epidemic Regions of Tanzania: Implications for Surveillance and Control.

IF 2.3 4区医学 Q2 PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH

Tropical Medicine & International Health Pub Date : 2025-10-01 Epub Date: 2025-09-02 DOI:10.1111/tmi.70032

Clement N Mweya

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引用次数: 0

Abstract

Objective: This study aimed to assess the prevalence of dengue virus (DENV) infection in Aedes aegypti mosquitoes and evaluate associated ecological and environmental factors in three inland districts (Bahi, Kyela, Ngorongoro) with distinct agro-ecological characteristics and no prior dengue outbreak reports.

Methods: A cross-sectional entomological study was conducted during the wet (April-June 2022) and dry (October-November 2022) seasons. Adult mosquitoes were collected indoors and outdoors using battery-powered aspirators, and immature stages were sampled from natural and artificial water containers. Mosquito pools were screened for DENV RNA using RT-qPCR.

Results: A total of 6459 Ae. aegypti mosquitoes were sampled (54% females). DENV RNA was detected in 0.6% (4/631) of the tested pools: one from Bahi and three from Kyela. No infections were detected in Ngorongoro. High mosquito density was observed in Kyela, particularly in paddy plantations and rice farms. Among DENV-positive pools, 100% (4/4) were collected near vegetation, suggesting that outdoor habitats are high-risk sites. The minimum infection rate was 0.6 (95% CI: 0.2-1.6) per 1000 mosquitoes.

Conclusion: This study confirms silent DENV circulation in Ae. aegypti populations in Tanzanian regions without prior epidemic reports. The detection of DENV in mosquitoes from Bahi and Kyela highlights the risk of future outbreaks and underscores the need for enhanced vector surveillance and integrated control strategies. These findings emphasise the urgency of preemptive public health measures to mitigate dengue spread in Tanzania. Limitations of the study include reliance on RT-qPCR without viral isolation or serotyping and the absence of concurrent human clinical data.

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坦桑尼亚非流行地区埃及伊蚊中登革热病毒的无声传播：对监测和控制的影响。

目的：本研究旨在评估埃及伊蚊中登革热病毒（DENV）感染的流行情况，并评估三个内陆地区（Bahi、Kyela、Ngorongoro）具有独特的农业生态特征和先前没有登革热暴发报告的生态环境因素。方法：在湿季（2022年4 - 6月）和旱季（2022年10 - 11月）进行横断面昆虫学研究。利用电池驱动的吸引器在室内和室外采集成蚊，并从天然和人工水容器中采集未成熟阶段的蚊子。采用RT-qPCR技术对蚊池进行DENV RNA筛选。结果：共有6459株Ae；采集埃及伊蚊（雌性54%）。在0.6%（4/631）的检测池中检测到DENV RNA：一个来自Bahi，三个来自Kyela。恩戈罗恩戈罗没有发现感染。凯拉省的蚊子密度很高，特别是稻田和稻田。在denv阳性池中，100%（4/4）采集于植被附近，提示室外生境为高危场所。最低感染率为0.6 / 1000 （95% CI: 0.2 ~ 1.6）。结论：本研究证实了白蛉的DENV沉默循环。坦桑尼亚地区的埃及伊蚊种群没有事先的流行病报告。在Bahi和Kyela的蚊子中发现DENV突出了未来爆发疫情的风险，并强调了加强媒介监测和综合控制战略的必要性。这些发现强调了采取先发制人的公共卫生措施以减轻登革热在坦桑尼亚传播的紧迫性。该研究的局限性包括依赖于RT-qPCR，没有病毒分离或血清分型，以及缺乏同步的人类临床数据。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Tropical Medicine & International Health 医学-公共卫生、环境卫生与职业卫生

CiteScore

4.80

自引率

0.00%

发文量

129

审稿时长

6 months

期刊介绍： Tropical Medicine & International Health is published on behalf of the London School of Hygiene and Tropical Medicine, Swiss Tropical and Public Health Institute, Foundation Tropical Medicine and International Health, Belgian Institute of Tropical Medicine and Bernhard-Nocht-Institute for Tropical Medicine. Tropical Medicine & International Health is the official journal of the Federation of European Societies for Tropical Medicine and International Health (FESTMIH).