Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
Department of Environmental and Occupational Health, School of Public Health, University of Ghana, Accra, Ghana.
PLoS One. 2021 Jun 1;16(6):e0234675. doi: 10.1371/journal.pone.0234675. eCollection 2021.
Aedes-borne viral diseases mainly Yellow Fever (YF), Dengue (DEN), Zika (ZIK) and Chikungunya (CHK) have contributed to many deaths' in the world especially in Africa. There have been major outbreaks of these diseases in West Africa. Although, YF outbreaks have occurred in Ghana over the years, no outbreak of DEN, ZIK and CHK has been recorded. However, the risk of outbreak is high due to its proximity to West African countries where outbreaks have been recently been recorded. This study surveyed the mosquito fauna to assess the risk of transmission of Yellow fever (YFV), Dengue (DENV), Chikungunya (CHKV) and Zika (ZIKV) viruses in Larabanga and Mole Game Reserve areas in Northern Ghana. The immature and adult stages of Aedes mosquitoes were collected from Larabanga and Mole Game Reserve area. There was a significant (P>0.001) number of mosquitoes collected during the rainy season than the dry season. A total of 1,930 Aedes mosquitoes were collected during the rainy season and morphologically identified. Of these, 1,915 (99.22%) were Aedes aegypti and 15 (0.22%) were Aedes vittatus. During the dry season, 27 Ae. aegypti mosquitoes were collected. A total of 415 Ae. aegypti mosquitoes were molecularly identified to subspecies level of which Ae. (Ae) aegypti aegypti was the predominant subspecies. Both Ae. aegypti aegypti and Ae aegypti formosus exist in sympatry in the area. All Aedes pools (75) were negative for DENV, ZIKV and CHKV when examined by RT- PCR. Three Larval indices namely House Index, HI (percentage of houses positive for Aedes larvae or pupae), Container Index, CI (the percentage of containers positive for Aedes larvae or pupae) and Breteau Index, BI (number of positive containers per 100 houses inspected) were assessed as a measure for risk of transmission in the study area. The HI, CI and BI for both sites were as follows; Mole Game Reserve (HI, 42.1%, CI, 23.5% and BI, 100 for rainy season and 0 for all indices for dry season) and Larabanga (39%, 15.5% and 61 for rainy season and 2.3%, 1.3% and 2.3 for dry season). The spatial distribution of Aedes breeding sites in both areas indicated that Aedes larvae were breeding in areas with close proximity to humans. Lorry tires were the main source of Aedes larvae in all the study areas. Information about the species composition and the potential role of Aedes mosquitoes in future outbreaks of the diseases that they transmit is needed to design efficient surveillance and vector control tools.
埃及伊蚊传播的病毒性疾病主要有黄热病（YF）、登革热（DEN）、寨卡（ZIK）和基孔肯雅热（CHK），这些疾病在世界范围内导致了许多人死亡，尤其是在非洲。西非曾发生过这些疾病的重大疫情。尽管加纳多年来曾发生过黄热病疫情，但尚未记录到登革热、寨卡和基孔肯雅热的疫情。然而，由于加纳靠近最近发生疫情的西非国家，因此爆发的风险很高。本研究调查了蚊子区系，以评估在加纳北部的拉腊邦加（Larabanga）和莫尔游戏保护区（Mole Game Reserve）地区传播黄热病（YFV）、登革热（DENV）、基孔肯雅热（CHKV）和寨卡热（ZIKV）病毒的风险。从拉腊邦加和莫尔游戏保护区采集了埃及伊蚊的幼虫和成虫阶段。雨季采集的蚊子数量明显多于旱季（P>0.001）。在雨季共采集了 1930 只埃及伊蚊，并进行了形态学鉴定。其中，1915 只（99.22%）为埃及伊蚊，15 只（0.22%）为埃及伊蚊。在旱季，共采集到 27 只埃及伊蚊。在分子水平上对 415 只埃及伊蚊进行了亚种鉴定，其中埃及伊蚊埃及亚种是主要亚种。在该地区，埃及伊蚊埃及亚种和埃及伊蚊华丽亚种共存。所有埃及伊蚊群（75 个）经 RT-PCR 检测均为登革热病毒、寨卡病毒和基孔肯雅病毒阴性。在研究区域内，使用三个幼虫指数（房屋指数、HI（有埃及伊蚊幼虫或蛹的房屋百分比）、容器指数、CI（有埃及伊蚊幼虫或蛹的容器百分比）和布雷特指数、BI（每 100 个检查的房屋中阳性容器的数量）来评估传播风险。两个地点的 HI、CI 和 BI 如下：莫尔游戏保护区（HI，42.1%，CI，23.5%，BI，100 用于雨季，所有指数均为 0 用于旱季）和拉腊邦加（39%，15.5%和 61 用于雨季，2.3%，1.3%和 2.3 用于旱季）。两个地区埃及伊蚊滋生地的空间分布表明，埃及伊蚊幼虫在与人类密切接触的地区滋生。在所有研究区域中，汽车轮胎都是埃及伊蚊幼虫的主要来源。需要了解有关这些物种组成和埃及伊蚊在未来传播疾病中的潜在作用的信息，以便设计有效的监测和病媒控制工具。
