Nwangwu Udoka C, Oguzie Judith U, Nwachukwu William E, Onwude Cosmas O, Dogunro Festus A, Diallo Mawlouth, Ezihe Chukwuebuka K, Agashi Nneka O, Eloy Emelda I, Anokwu Stephen O, Anioke Clementina C, Ikechukwu Linda C, Nwosu Chukwuebuka M, Nwaogo Oscar N, Ngwu Ifeoma M, Onyeanusi Rose N, Okoronkwo Angela I, Orizu Francis U, Etiki Monica O, Onuora Esther N, Adeorike Sobajo Tope, Okeke Peter C, Chukwuekezie Okechukwu C, Ochu Josephine C, Ibrahim Sulaiman S, Ifedayo Adetifa, Ihekweazu Chikwe, Happi Christian T
National Arbovirus and Vectors Research Centre (NAVRC), Enugu, Nigeria.
Department of Zoology and Environmental Biology, University of Nigeria, Nsukka, Enugu State, Nigeria.
bioRxiv. 2024 Jan 15:2024.01.15.575625. doi: 10.1101/2024.01.15.575625.
Since its reemergence in 2017, yellow fever (YF) has been active in Nigeria. The Nigeria Centre for Disease Control (NCDC) has coordinated responses to the outbreaks with the support of the World Health Organization (WHO). The National Arbovirus and Vectors Research Centre (NAVRC) handles the vector component of these responses. This study sought to identify the vectors driving YF transmission and any of the targeted arboviruses and their distribution across states.
Eggs, larvae and pupae as well as adult mosquitoes were collected in observational, analytical, and cross-sectional surveys conducted in sixteen YF outbreak states between 2017 and 2020. Adult mosquitoes (field-collected or reared from immature stages) were morphologically identified, and arboviruses were detected using RT-qPCR at the African Centre of Excellence for Genomics of Infectious Diseases (ACEGID).
mosquitoes were collected in eleven of the sixteen states surveyed and the mosquitoes in nine states were found infected with arboviruses. A total of seven species were collected from different parts of the country. was the most dominant (51%) species, whereas was the least (0.2%). Yellow fever virus (YFV) was discovered in 33 (~26%) out of the 127 mosquito pools. In addition to YFV, the Chikungunya virus (CHIKV) was found in nine pools. Except for , all the species tested positive for at least one arbovirus. YFV-positive pools were found in six (6) species while CHIKV-positive pools were only recorded in two species. Edo State had the most positive pools (16), while Nasarawa, Imo, and Anambra states had the least (1 positive pool). Breteau and house indices were higher than normal transmission thresholds in all but one state.
In Nigeria, there is a substantial risk of arbovirus transmission by mosquitoes, with YFV posing the largest threat at the moment. This risk is heightened by the fact that YFV and CHIKV have been detected in vectors across outbreak locations. Hence, there is an urgent need to step up arbovirus surveillance and control activities in the country.
自2017年再次出现以来，黄热病（YF）一直在尼日利亚活跃传播。尼日利亚疾病控制中心（NCDC）在世卫组织（WHO）的支持下协调应对疫情。国家虫媒病毒和病媒研究中心（NAVRC）负责这些应对措施中的病媒部分。本研究旨在确定驱动黄热病传播的病媒以及任何目标虫媒病毒及其在各州的分布情况。
在2017年至2020年期间，于16个黄热病疫情爆发州开展了观察性、分析性和横断面调查，收集了蚊卵、幼虫、蛹以及成年蚊子。对成年蚊子（野外采集或由未成熟阶段饲养而来）进行形态学鉴定，并在非洲传染病基因组学卓越中心（ACEGID）使用逆转录定量聚合酶链反应（RT-qPCR）检测虫媒病毒。
在调查的16个州中的11个州采集到了蚊子，且在9个州发现蚊子感染了虫媒病毒。从该国不同地区共采集到7个蚊种。 是最主要的蚊种（占51%），而 是最少的（占0.2%）。在127个 蚊群中，有33个（约26%）发现了黄热病毒（YFV）。除了YFV，在9个蚊群中还发现了基孔肯雅病毒（CHIKV）。除 外，所有蚊种至少对一种虫媒病毒检测呈阳性。YFV阳性蚊群在6个蚊种中被发现，而CHIKV阳性蚊群仅在2个蚊种中被记录到。江户州的阳性蚊群最多（16个），而纳萨拉瓦州、伊莫州和阿南布拉州最少（各有1个阳性蚊群）。除一个州外，所有州的布雷托指数和房屋指数均高于正常传播阈值。
在尼日利亚， 蚊子传播虫媒病毒的风险很大，目前YFV构成的威胁最大。YFV和CHIKV在疫情爆发地区的病媒中均被检测到，这一事实加剧了这种风险。因此，该国迫切需要加强虫媒病毒监测和控制活动。
