Department of Biology, Arba Minch University, Arba Minch, Ethiopia.
Malaria and NTD Research Division, Armauer Hansen Research Institute, Addis Ababa, Ethiopia.
Parasit Vectors. 2024 Sep 28;17(1):408. doi: 10.1186/s13071-024-06493-1.
The efficacy of vector control tools depends on the behavior of the vector species. Many studies have sought to determine the feeding behavior of Anopheles mosquitoes in different settings of Ethiopia. We have performed a systematic review aimed to generate pooled evidence on the overall and species-specific blood meal sources of Anopheles mosquitoes in Ethiopia.
A search for relevant articles was performed in two electronic databases (PubMed and Science Direct) and three search engines (Google Scholar, Research Gate and Google) between 11 March and 2 April 2024. Following the initial identification of articles, we used EndNote X8 software and removed duplicate articles and screened the remaining articles by careful reading of their titles and abstracts. The full text of articles that passed this screening phase was retrieved, read and evaluated against predetermined selection criteria. The final decision for inclusion in the systematic review was made after a methodological quality check using the JBI critical appraisal checklist. All relevant data were extracted from tables, figures and texts of the included articles using a premade template in Excel, and the data were analyzed using Stata version 14 software.
Of the 2431 studies identified, 27 met the inclusion criteria; all were published between 1997 and 2024. At 215 data points (frequency of tests of each Anopheles species by location and method of mosquito collections), 18,771 Anopheles mosquitoes belonging to 23 species or species complexes were tested for blood meal sources. The commonest sources of blood meals for Anopheles mosquitoes were bovine (36.0%, n = 6758) and human (29.4%, n = 5520). Among the tested anophelines, Anopheles (An.) arabiensis accounted for 67.9% (n = 12,741), followed by An. pharoensis, An. demeilloni and An. stephensi at 10.0%, 5.6% and 4.4%, respectively. Overall, there was no difference in the mean proportion of An. arabiensis detected with domestic animal blood (33.4%, 95% confidence interval [CI] 32.4-34.4%) and those detected with human blood (31.8%, 95% CI 30.9-32.8%). However, a greater proportion of the outdoor collected An. arabiensis were found to feed on bovines (47.9%, 95% CI 35.3-60.6) compared to humans (12.9%, 95% CI 0.8-24.9, P < 0.01). The foraging ratio (FR), which accounts for host availability, was greater for bovines (FR = 0.7) than for humans (FR = 0.2) for An. arabiensis, indicating preferential feeding on bovine hosts. This host preference was supported by the host preference index (human:bovine = 0.4). Anopheles pharoensis was detected with a slightly higher human blood index (53.5%, n = 1005) compared to bovine blood index (45.2%, n = 849). In contrast, An. demeilloni, An. coustani and An. marshalli were detected with a higher bovine blood index. Recently invaded urban malaria vector, An. stephensi was found with a higher ovine blood index.
Bovine and human hosts are common sources of a blood meal for Anopheles mosquitoes. In terms of host availability, An. arabiensis showed preferential feeding on bovines/cattle. Targeting domestic animals, bovines and ovines with endectocides could supplement current vector control interventions.
The protocol of this study was registered on the International Prospective Register of Systematic Reviews, registration no. CRD42024515725.
病媒控制工具的效果取决于病媒物种的行为。许多研究试图确定埃塞俄比亚不同环境中疟蚊的取食行为。我们进行了一项系统评价，旨在生成关于埃塞俄比亚疟蚊总类和特定物种的血液来源的综合证据。
在 2024 年 3 月 11 日至 4 月 2 日期间，我们在两个电子数据库（PubMed 和 Science Direct）和三个搜索引擎（Google Scholar、Research Gate 和 Google）中搜索相关文章。在初步确定文章后，我们使用 EndNote X8 软件去除重复文章，并仔细阅读标题和摘要筛选其余文章。通过使用 JBI 批判性评估清单进行方法学质量检查，对通过此筛选阶段的文章全文进行检索、阅读和评估。在最终决定纳入系统评价之前，使用 Excel 中的预制表从包含的文章的表格、图表和文本中提取所有相关数据，并使用 Stata 版本 14 软件进行分析。
在确定的 2431 项研究中，有 27 项符合纳入标准；所有研究均发表于 1997 年至 2024 年之间。在 215 个测试点（根据蚊子采集地点和方法对每种疟蚊进行测试的频率）中，测试了 18771 只属于 23 种或种复合体的疟蚊，以确定其血液来源。疟蚊最常见的血液来源是牛（36.0%，n=6758）和人类（29.4%，n=5520）。在所测试的疟蚊中，按出现频率计算，An. arabiensis 占 67.9%（n=12741），其次是 An. pharoensis、An. demeilloni 和 An. stephensi，分别占 10.0%、5.6%和 4.4%。总体而言，用家畜血液检测到的 An. arabiensis 平均比例（33.4%，95%置信区间 [CI] 32.4-34.4%）与用人血检测到的比例（31.8%，95% CI 30.9-32.8%）没有差异。然而，与人类相比，更多的户外采集的 An. arabiensis 被发现以牛为食（47.9%，95% CI 35.3-60.6%），而不是人类（12.9%，95% CI 0.8-24.9%，P<0.01）。考虑到宿主可用性的觅食比率（FR），牛的 FR（0.7）大于人类的 FR（0.2），这表明疟蚊更喜欢以牛为食。宿主偏好指数（人类：牛=0.4）支持了这种宿主偏好。An. pharoensis 用人血的检测指数（53.5%，n=1005）略高于牛血的检测指数（45.2%，n=849）。相比之下，An. demeilloni、An. coustani 和 An. marshalli 以牛血为主。最近入侵的城市疟疾媒介 An. stephensi 则以较高的羊血指数为食。
牛和人类是疟蚊常见的血液来源。就宿主可用性而言，An. arabiensis 对牛有优先取食倾向。针对家畜、牛和羊用内吸杀虫剂进行靶向处理，可以补充当前的病媒控制干预措施。
本研究方案在国际前瞻性系统评价登记册上进行了注册，注册号为 CRD42024515725。
