加纳南部两个地点的幼虫栖息地稳定性和生产力。

Larval habitat stability and productivity in two sites in Southern Ghana.

机构信息

Department of Medical Laboratory Science, School of Biomedical and Allied Health Sciences, University of Ghana, Korle-Bu, Accra, Ghana.

Department of Medical Microbiology, University of Ghana Medical School, University of Ghana, Korle-Bu, Accra, Ghana.

出版信息

Malar J. 2023 Mar 2;22(1):74. doi: 10.1186/s12936-023-04498-2.

DOI:10.1186/s12936-023-04498-2

PMID:36864430

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9983185/

Abstract

BACKGROUND

Mosquito larval source management (LSM) is a valuable additional tool for malaria vector control. Understanding the characteristics of mosquito larval habitats and its ecology in different land use types can give valuable insight for an effective larval control strategy. This study determined the stability and productivity of potential anopheline larval habitats in two different ecological sites: Anyakpor and Dodowa in southern Ghana.

METHODS

A total of 59 aquatic habitats positive for anopheline larvae were identified, and sampled every two weeks for a period of 30 weeks using a standard dipping method. Larvae were collected using standard dippers and were raised in the insectary for identification. Sibling species of the Anopheles gambiae sensu lato (s.l.) were further identified by polymerase chain reaction. The presence of larval habitats, their stability and larvae positive habitats were compared between the two sites using Mann-Whitney U and the Kruskal-Wallis test. Factors affecting the presence of An. gambiae larvae and physicochemical properties at the sites were determined using multiple logistic regression analysis and Spearman's correlation.

RESULTS

Out of a total of 13,681 mosquito immatures collected, 22.6% (3095) were anophelines and 77.38% (10,586) were culicines. Out of the 3095 anophelines collected, An. gambiae s.l. was predominant (99.48%, n = 3079), followed by Anopheles rufipes (0.45%, n = 14), and Anopheles pharoensis (0.064%, n = 2). Sibling species of the An. gambiae consisted of Anopheles coluzzii (71%), followed by An. gambiae s.s. (23%), and Anopheles melas (6%). Anopheles mean larval density was highest in wells [6.44 (95% CI 5.0-8.31) larvae/dip], lowest in furrows [4.18 (95% CI 2.75-6.36) larvae/dip] and man-made ponds [1.20 (95% CI 0.671-2.131) larvae/dip].The results also revealed habitat stability was highly dependent on rainfall intensity, and Anopheles larval densities were also dependent on elevated levels of pH, conductivity and TDS.

CONCLUSION

The presence of larvae in the habitats was dependent on rainfall intensity and proximity to human settlements. To optimize the vector control measures of malaria interventions in southern Ghana, larval control should be focused on larval habitats that are fed by underground water, as these are more productive habitats.

摘要

背景

蚊虫幼虫源管理（LSM）是疟疾媒介控制的一种有价值的附加工具。了解不同土地利用类型中蚊虫幼虫栖息地的特征及其生态学特性，可以为有效的幼虫控制策略提供有价值的见解。本研究旨在确定在加纳南部的两个不同生态地点——Anyakpor 和 Dodowa 的潜在按蚊幼虫栖息地的稳定性和生产力。

方法

共确定了 59 个阳性按蚊幼虫的水生栖息地，并使用标准浸渍法每两周采集一次，共采集 30 周。幼虫使用标准的舀水器收集，并在昆虫室中进行鉴定。冈比亚按蚊复合体（An. gambiae s.l.）的姐妹种通过聚合酶链反应进一步鉴定。使用 Mann-Whitney U 检验和 Kruskal-Wallis 检验比较了两个地点之间幼虫栖息地的存在、稳定性和幼虫阳性栖息地。使用多因素逻辑回归分析和 Spearman 相关分析确定了影响按蚊幼虫存在和现场理化特性的因素。

结果

在总共收集的 13681 只蚊子幼虫中，22.6%（3095 只）为按蚊，77.38%（10586 只）为库蚊。在收集的 3095 只按蚊中，冈比亚按蚊复合体占优势（99.48%，n=3079），其次是丽纹按蚊（0.45%，n=14）和淡色库蚊（0.064%，n=2）。冈比亚按蚊复合体的姐妹种包括冈比亚疟蚊（71%），其次是冈比亚按蚊（23%）和淡色库蚊（6%）。按蚊幼虫平均密度最高的是水井[6.44（95%置信区间 5.0-8.31）只/次]，最低的是沟渠[4.18（95%置信区间 2.75-6.36）只/次]和人工池塘[1.20（95%置信区间 0.671-2.131）只/次]。结果还表明，栖息地的稳定性高度依赖于降雨量强度，而按蚊幼虫密度也依赖于 pH 值、电导率和 TDS 值的升高。