10.1  Introduction to indoor residual spraying (IRS)

In Study Session 9 you learned that environmental management and other larva killing activities are important in malaria prevention. Larval control is the first line of defense in malaria prevention; its impact in reducing the burden of malaria can be significant in countries like Ethiopia, where vector breeding sites are relatively limited and generally clearly defined. However, it is impossible to identify all vector breeding sites and kill all larvae before they become flying adults. Once mosquitoes become flying adults, environmental management has little impact in controlling them, so measures to control adult mosquitoes are needed to protect people from malaria.

Indoor residual spraying (IRS) has been used in Ethiopia since the 1960s, and has three main aims:

  1. To reduce the seasonal rise in malaria.
  2. To prevent epidemics.
  3. To control epidemics.

Until 2009, IRS was planned and implemented by specialised staff from district, zonal and regional health offices. Temporary spray operators were recruited from district towns and sent to villages to do the spraying.

However IRS will now be planned and implemented by Health Extension Workers and Health Extension Practitioners like yourself in your own village, with the co-operation of your local community. As part of this process, you will need to train spray operators (the people who do the spraying) selected from the community, supervise the spray operation, and carry out minor maintenance of the spray pumps (equipment used to spray insecticides).

Learning Outcomes for Study Session 10

10.2  How does IRS reduce the mosquito population?