U.S. President's Malaria Initiative (PMI) VectorLink Project, Abt Associates, Yaoundé, Cameroon.
Central African Organization for Endemic Disease Control (OCEAC), Yaoundé, Cameroon.
Malar J. 2023 Apr 13;22(1):123. doi: 10.1186/s12936-023-04552-z.
Malaria remains one of the main causes of morbidity and mortality in Cameroon. To inform vector control intervention decision making, malaria vector surveillance was conducted monthly from October 2018 to September 2020 in five selected sentinel sites (Gounougou and Simatou in the North, and Bonabéri, Mangoum and Nyabessang in the South).
Human landing catches (HLCs), U.S. Centers for Disease Control and Prevention (CDC) light traps, and pyrethrum spray catches (PSCs) were used to assess vector density, species composition, human biting rate (HBR), endophagic index, indoor resting density (IRD), parity, sporozoite infection rates, entomological inoculation rate (EIR), and Anopheles vectorial capacity.
A total of 139,322 Anopheles mosquitoes from 18 species (or 21 including identified sub-species) were collected across all sites. Out of the 18 species, 12 were malaria vectors including Anopheles gambiae sensu lato (s.l.), Anopheles funestus s.l.., Anopheles nili, Anopheles moucheti, Anopheles paludis, Anopheles demeilloni, Anopheles. pharoensis, Anopheles ziemanni, Anopheles multicinctus, Anopheles tenebrosus, Anopheles rufipes, and Anopheles marshallii. Anopheles gambiae s.l. remains the major malaria vector (71% of the total Anopheles) collected, though An. moucheti and An. paludis had the highest sporozoite rates in Nyabessang. The mean indoor HBR of Anopheles ranged from 11.0 bites/human/night (b/h/n) in Bonabéri to 104.0 b/h/n in Simatou, while outdoors, it varied from 24.2 b/h/n in Mangoum to 98.7 b/h/n in Simatou. Anopheles gambiae s.l. and An. moucheti were actively biting until at least 8:00 a.m. The mean Anopheles IRD was 17.1 females/room, and the parity rate was 68.9%. The mean EIRs for each site were 55.4 infective bites/human/month (ib/h/m) in Gounougou, 99.0 ib/h/m in Simatou, 51.2 ib/h/m in Mangoum, 24.4 ib/h/m in Nyabessang, and 18.1 ib/h/m in Bonabéri. Anopheles gambiae s.l. was confirmed as the main malaria vector with the highest vectorial capacity in all sites based on sporozoite rate, except in Nyabessang.
These findings highlight the high malaria transmission occurring in Cameroon and will support the National Malaria Control Program to design evidence-based malaria vector control strategies, and deployment of effective and integrated vector control interventions to reduce malaria transmission and burden in Cameroon, where several Anopheles species could potentially maintain year-round transmission.
疟疾仍然是喀麦隆发病率和死亡率的主要原因之一。为了为媒介控制干预决策提供信息，2018 年 10 月至 2020 年 9 月，在五个选定的哨点（北部的 Gounougou 和 Simatou，以及南部的 Bonabéri、Mangoum 和 Nyabessang）每月进行疟疾媒介监测。
使用人体诱捕、美国疾病控制与预防中心（CDC）诱捕器和除虫菊喷雾诱捕来评估媒介密度、物种组成、人叮咬率（HBR）、内吸指数、室内密度（IRD）、产育率、孢子感染率、昆虫接种率（EIR）和疟疾病媒能力。
在所有地点共收集到 139322 只来自 18 种（或包括已确定亚种在内的 21 种）的疟疾病媒按蚊。在这 18 种蚊子中，有 12 种是疟疾媒介，包括冈比亚按蚊（s.l.）、致倦库蚊（s.l.）、不吉按蚊、穆氏按蚊、淡色库蚊、指名按蚊、法氏按蚊、齐氏按蚊、嗜人按蚊、暗翅按蚊、刺扰按蚊和曼氏按蚊。冈比亚按蚊仍然是主要的疟疾媒介（占总按蚊的 71%），尽管在 Nyabessang 中，按蚊穆氏和按蚊淡色库蚊的孢子感染率最高。按蚊室内 HBR 平均值从 Bonabéri 的 11.0 人/夜（b/h/n）到 Simatou 的 104.0 b/h/n，而室外 HBR 从 Mangoum 的 24.2 b/h/n 到 Simatou 的 98.7 b/h/n。冈比亚按蚊和按蚊穆氏一直到至少上午 8:00 都在积极叮咬。按蚊室内密度平均值为 17.1 只/间，产育率为 68.9%。每个地点的平均 EIR 分别为：Gounougou 的 55.4 感染性叮咬/人/月（ib/h/m）、Simatou 的 99.0 ib/h/m、Mangoum 的 51.2 ib/h/m、Nyabessang 的 24.4 ib/h/m 和 Bonabéri 的 18.1 ib/h/m。冈比亚按蚊被证实是主要的疟疾媒介，除了在 Nyabessang 之外，在所有地点的孢子感染率方面，它的媒介能力最高。
这些发现突显了喀麦隆疟疾传播的高发生率，将支持国家疟疾控制计划制定基于证据的疟疾媒介控制策略，并部署有效和综合的媒介控制干预措施，以减少疟疾在喀麦隆的传播和负担，在那里，几种按蚊物种可能会全年保持传播。
