Mathania Mary Mathew, Munisi David Zadock, Silayo Richard S
Department of Basic and Behavioral Sciences, School of Nursing, Saint John's University of Tanzania, Dodoma, Tanzania.
Department of Microbiology, Parasitology and Biotechnology, College of Veterinary Medicine and Biomedical Sciences, Sokoine University of Agriculture, Morogoro, Tanzania.
Parasite Epidemiol Control. 2020 Sep 1;11:e00179. doi: 10.1016/j.parepi.2020.e00179. eCollection 2020 Nov.
In order to be able to design and implement control measures directed to the mosquito larva stages an understanding of the spatial and temporal distribution and its determinants in different malaria transmission settings is important. This study therefore, intended to determine the spatial and temporal distribution of mosquito's larvae and its determinants in two urban sites with different transmission levels, in Tanzania.
This study was conducted in Dodoma and Morogoro regions in Tanzania. The study was an ecological study of repeated cross-sectional type. Searching for water bodies in the selected wards was done by going around all streets. Potential breeding sites were given unique identification numbers and larval sampling was done using the standard dipping method with a 350 ml mosquito scoop and a calibrated pipette. Visual identification of presence of larvae and its abundance in each sampling were used to describe the larvae density. A sample of mosquitoes which emerged from collected larvae, were processed for species identification using PCR. Descriptive statistics were arrived at by calculating different proportions for the variables. The overall impact of the variables on the density of larvae was tested using multiple logistic regression. Variables with -value less than 0.05 were regarded as significant.
A total of 724 water bodies out of which, 576 (79.6%) potential breeding sites were analyzed. It was found that, most (96.2%) of the potential breeding sites were manmade and most (59.5%) were less than 5 m in diameter and 87.2% were within 100 m from human settlement. Out of all the potential breeding sites, 69.8% and 30.2% were in Morogoro and Dodoma respectively, out of which 72.2% and 68.4% respectively, were found during rainy season. Habitats with clean water, at a distance of 10-100 m from the house, in natural, shaded and partial sunlight habitats had higher odds of having high density of mosquito larvae than their counterparts (p 05). The PCR analysis showed that 72.5% were 4.5% 0.5% and 20% while 2.5% of the samples could not be identified because DNA was not amplified
Type of water, distance from the breeding site to human settlement, light intensity and habitat origin were significant predictors of variation on the spatial and temporal distribution of Anopheles mosquito breeding sites. With increased global emphasis on control measures that targets mosquito immature stages; we recommend that larval control measures should be developed while considering the findings from this study.
为了能够设计并实施针对蚊虫幼虫阶段的控制措施，了解不同疟疾传播环境中蚊虫幼虫的时空分布及其决定因素非常重要。因此，本研究旨在确定坦桑尼亚两个不同传播水平的城市地区蚊虫幼虫的时空分布及其决定因素。
本研究在坦桑尼亚的多多马和莫罗戈罗地区进行。该研究是一项重复横断面类型的生态学研究。通过走遍选定病房的所有街道来寻找水体。给潜在的繁殖地赋予唯一的识别号码，并使用标准的 dipping 方法，用一个 350 毫升的蚊虫勺和一个校准的移液管进行幼虫采样。通过目视识别每个采样中幼虫的存在及其丰度来描述幼虫密度。对从收集的幼虫中羽化出的一部分蚊子进行处理，使用聚合酶链反应（PCR）进行物种鉴定。通过计算变量的不同比例得出描述性统计数据。使用多元逻辑回归测试变量对幼虫密度的总体影响。p 值小于 0.05 的变量被视为具有显著性。
总共分析了 724 个水体，其中 576 个（79.6%）为潜在繁殖地。结果发现，大多数（96.2%）潜在繁殖地是人造的，大多数（59.5%）直径小于 5 米，87.2%距离人类住区不到 100 米。在所有潜在繁殖地中，分别有 69.8%和 30.2%位于莫罗戈罗和多多马，其中分别有 72.2%和 68.4%是在雨季发现的。与其他环境相比，距离房屋 10 - 100 米、水质清洁、处于自然、阴凉和部分阳光照射环境中的栖息地，有更高密度蚊虫幼虫的几率更高（p < 0.05）。PCR 分析表明，72.5%为 [此处原文缺失部分信息]，4.5%为 [此处原文缺失部分信息]，0.5%为 [此处原文缺失部分信息]，20%为 [此处原文缺失部分信息]，而 2.5%的样本因 DNA 未扩增无法鉴定。
水体类型、繁殖地与人类住区的距离、光照强度和栖息地来源是按蚊繁殖地时空分布变化的重要预测因素。随着全球对针对蚊虫未成熟阶段的控制措施的重视增加；我们建议在制定幼虫控制措施时应考虑本研究的结果。
