Societal Uses of the Main Water Bodies Inhabited by Malaria Vectors and Implications for Larval Source Management
Authors: Kahamba Najat F. , Tarimo Felista , Kifungo Khamisi , Mponzi Winifrida , Kinunda Siaba A. , Simfukwe Alfred , Mapua Salum , Msugupakulya Betwel , Baldini Francesco , Ferguson Heather M. , Okumu Fredros O. , Finda Marceline F. 
Published: June 2024

Introduction

Larval source management (LSM) can effectively suppress mosquito populations at source and provides an opportunity to address major challenges such as insecticide resistance that undermine primary interventions like insecticide-treated nets (ITNs). While mostly implemented in urban and arid settings, emerging research indicates its potential in some rural settings in east and southern Africa, where the main malaria vector,Anopheles funestus, prefers permanent and semi-permanent water bodies that support year-round transmission. Targeting these unique habitats could amplify effectiveness of LSM but requires careful considerations of local societal practices and expectations - particularly since mosquito breeding sites often also serve as community water resources. The aim of this study was therefore to explore how the societal uses of aquatic habitats by local communities in rural south-eastern Tanzania might influence LSM strategies, focusing on habitats frequented byAn. funestus.

Methods

This study was conducted in three villages in the Ulanga and Malinyi districts of southeastern Tanzania using a mixed-methods approach. Quantitative data were collected through a cross-sectional surveillance of all aquatic habitats, while qualitative data were gathered via a combination of individual unstructured interviews, focus group discussions with various community groups and field observations of community practices and activities. Data analysis employed weaving and inferencing techniques to integrate findings from both quantitative and qualitative components, thereby developing a comprehensive understanding from the respondents’ perspectives.

Results

A survey of 931 aquatic habitats revealed that 73% contained mosquito larvae, with late instar An. funestus identified in 23% of these habitats. River streams segments were the most common habitat type, accounting for 41%, followed by ground pools at 4%; other types included pits, rice fields, ditches, and puddles. Community use was noted for 90% of these habitats, including 95% of those with An. funestus larvae, for activities such as domestic chores such as cooking, washing utensils, washing clothes and bathing, agriculture, livestock rearing, brickmaking, and fishing. Focus group discussions indicated community readiness to implement LSM, favoring larviciding and habitat manipulation over habitat removal. Community concerns regarding LSM centered on the safety of larvicides for animal and human health and their environmental impact. The discussions proved the need for LSM interventions to integrate seamlessly with daily activities; and for community education on LSM safety and efficacy.

Conclusion

This study offers valuable insights into community perspectives on LSM for malaria control in rural settings, emphasizing the dual role of aquatic habitats as both mosquito breeding sites and community water sources. This presents a set of unique challenges and opportunities – suggesting that LSM strategies must address both the biological aspects of mosquito control and the socio-economic realities of local communities. Notably, there was a marked preference for larviciding and habitat manipulation over habitat removal, with a strong emphasis on health and environmental safety. Overall, the study highlights the critical importance of educating communities, adopting culturally sensitive approaches to LSM, and aligning LSM strategies with the needs, perspectives, and daily lives of local communities.