Empowering the community towards malaria elimination; the use of Integrated vector management

This is a PhD project by Emmanuel Hakizimana, supervised by Prof. Dr. W. Takken and Dr. C.J.M. Koenraadt. This study conducted in complex rural mosquito breeding areas, mainly rice fields, showed a significant reduction in density of anopheline and culicine larval mosquitoes after application of Bti, and of adult stages of anophelines, but not culicines where implemented either by expert supervised or community based teams. The impact was more noticeable in open water bodies where the density and the habitat occupancy of mosquito larvae and pupae were reduced to near zero in inter-crop lands and to zero in dams. Although, this study covered only one cycle of rice growing, it demonstrated that the application of Bti may lead to the elimination of larval mosquitoes in open water bodies and to gain a moderate impact in complex habitats of rice fields. Importantly, this method of larval control caused a strong reduction in the biting fraction of malaria vectors, and can be expected to impact on malaria
transmission.
The effectiveness of Bti in rice paddies has to be investigated more for multiple seasons of rice farming and explore the suitable phase of rice growing to be targeted for impact on mosquitoes. Moreover, some inaccessible water bodies with simple spraying equipment have been reported in this study and appropriate equipment per types of breeding sites has to be defined and made available before larviciding is conducted. Based on their technical skills on
pest management and handling spraying equipment, the rice farmers and other leaders of community-based organizations seem to be the appropriate community groups to lead and sustain implementation of larval control using a biological larvicide. They should be empowered with affordable resources through additional knowledge and skills on the bio-ecology and control of mosquitoes and then integrate this innovative vector control tool into their usual farming activities.

The intervention study is classified as a non-randomized trial with control and included one control and two Larval Source Management
(LSM) arms. Baseline information on potential mosquito breeding sites was collected in the study area, as well as on stakeholder pre-engagement and socio-economic status. All permanent or semi-permanent water bodies were mapped prior to the intervention. These included the four marshlands used for irrigated rice growing (Nyaburiba, Kibaza, Gatare and Kizanye), one marshland used by the community for growing seasonal subsistence crops (Nyagafunzo), and 19 so-called hill dams for harvesting rain water (each approximately 200 m2 in size). Nyaburiba (35 ha) was selected as the control arm, without any application of Bti. For the “expert supervised” arm (hereafter referred to as “ES‟), Kibaza (27 ha; entitled “ES1”), Nyagafunzo (8 ha; “ES2”) and all 19 water hill dams (“ES3‟) were selected. For the third arm, “community-based‟ application of Bti (hereafter referred to as “CB‟), Gatare (25 ha, “CB1‟) and Kizanye (8 ha; “CB2‟) marshlands were selected. The minimum distance between intervention arms was estimated at five km. One month before the Bti application, a baseline survey on the perception, engagement and willingness to pay for LSM was carried out by a team consisting of a sociologist and an economist. At the same time, the entomological sampling points were identified, numbered and mapped. This activity was followed by baseline entomological surveys on larval and adult stages of mosquitoes and led by trained entomology technicians in collaboration with community members.

Project details

Measurement of Transmission
Program Evaluation
Social Science
Vector Control

Sep 2011 — Feb 2019

Rwanda

Malaria Elimination Programme for Ruhuha (MEPR)

Larval source management