Kamija Phiri

Filming the unseen: building malaria out by addressing mosquito flight

Principal investigator

Kamija Phiri

School of Public Health and Family Medicine, College of Medicine, University of Malawi, P.O. Box 360, Blantyre, Malawi

Co-investigators

  1. Robert S. McCann

  2. CJM (Sander) Koenraadt

  3. Jeroen Spitzen

    Laboratory of Entomology, Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands

  4. Florian Muijres

  5. Martin Lankheet

    Experimental Zoology Group, Department Animal Sciences, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands

  6. Ike Phiri

    Department of Architecture, The Polytechnic, University of Malawi, Blantyre, Malawi

  7. James Logan

    Department of Disease Control, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT

Lay Summary

The parasite that causes malaria is transmitted from person to person by Anopheles mosquitoes. In Africa the mosquitoes that transmit malaria mostly bite people in (or near) their houses. In the areas most affected by malaria, the majority of houses are built with features that don’t keep out mosquitoes (for example, open windows and open eaves), and the mosquitoes that transmit malaria enter houses through these features. It is becoming clear that people living in these types of houses are at a greater risk of getting malaria, which has led to an increased interest in ways to modify house designs as a way to control malaria. Still, there are many different options for improved house designs. For example, closing eaves completely might be more durable, but screening eaves might provide better ventilation in the house – an important consideration for people without electricity to run fans or air conditioning. To help guide these types of decisions, we need to have a better understanding of how mosquitoes behave near people’s houses. Here, we propose to study the flight behaviour of one of the major malaria vectors in Africa to provide valuable information about how these mosquitoes find and enter houses. We will set up a large enclosure in Malawi, made of durable screening, in order to release mosquitoes in a controlled environment where we can use a video-recording system to track their flight paths. This video-recording system will use special lighting (infra-red) so as not to affect the behaviour of the mosquitoes, and it will use four synchronised cameras to track their paths in 3D. There will be a house inside the enclosure, built to resemble a typical house in rural Malawi, and we will observe the flight paths of mosquitoes near the house. Over 30 nights of observations, we will adjust the eaves and windows of the house to fit five different designs, where the eaves and windows are either open, closed, or screened in different combinations. During each night, two volunteers will sleep inside the house to attract mosquitoes into the house. They will each sleep under an untreated bed net and next to a mosquito trap to collect mosquitoes that enter the house. We will release 500 mosquitoes in the enclosure each night. The mosquitoes will come from a colony of mosquitoes reared under controlled conditions at our field station, which means we will be sure that they are not carrying the malaria parasite, and the volunteers will not be at risk of getting malaria during the experiments. The cameras and traps will run from 20:00 to 06:00 each night. The flight paths of the mosquitoes will be analysed to understand how they approach the house, where they spend their time near the house before entering it, where they typically enter the house, and how these behaviours change between the five different designs being tested.