Indoor Residual Spraying - Do it right

| 24 Aug 2023
Africa Fighting Malaria

On August 14, 2023 Uganda's New Vision newspaper reported that malaria control spraymen were "resisted" in Munyonyo, a suburb of Kampala, as they attempted to conduct an indoor residual spraying program. This incident highlights the need for good information, education and communication in malaria control and also provides evidence of the damage that the highly politicized and damaging debate around the use of DDT has done for malaria control.

Indoor residual spraying, or IRS, involves the careful application of small amounts of insecticide on the inside walls of houses. Depending on the class of insecticide used, the chemical will either kill, repel or irritate the female Anopheles mosquito - some insecticides, such as DDT function in all three modes. The reason for conducting an IRS program is to interrupt the transmission of malaria from human to human via the vector - the Anopheles mosquito and to reduce the life-span of mosquitoes. Decades of evidence has shown that IRS is one of the most effective ways of controlling and in some cases eradicating the disease.

The Ugandan Government's policy of including IRS along with other interventions, such as the use of long lasting insecticidal nets (LLINs) and effective and prompt treatment of malaria cases, the right one. IRS programs in the south of Uganda have dramatically reduced the burden of disease and thanks to thorough education and communication programs, over 95% of homeowners allowed spraymen to enter their houses and spray the walls.

The spraying program in Munyonyo was managed by a private contractor, Balton, which used the pyrethroid class of insecticide for spraying. There are over 12 insecticides that have been approved by the World Health Organization for use in IRS. One of the insecticides, DDT, has been at the center of ongoing controversy in Uganda. DDT is probably the most effective insecticide for IRS because it is cheap, easy to use, has a long residual action lasting usually around 12 months and has three modes of action, repellency, irritancy and toxicity. Yet DDT is banned for use in agriculture and universally is stigmatized for its widespread use during the 1950s and 60s (mostly in the West) on crops.

The debate around DDT in Uganda has been handled poorly by all parties. There has been a failure to distinguish between the intervention - IRS and the chemical DDT. People frequently conflate the two, yet DDT is only one chemical that can be used in IRS. Frustratingly people equate IRS with DDT and assume that only this insecticide will be used.

Some environmentalists and certain politicians, most notably Ken Lukyamuzi, have been vocal and outspoken about the use of DDT. For instance, at a public rally captured on camera and available on YouTube.com, https://www.youtube.com/watch?v=4t2B-jbGIn4, Lukyamuzi claims among other things that DDT is dangerous, will be used by the Museveni Government to "murder people in broad daylight", that it will be sprayed on trees and contaminate crops. Lukyamuzi goes on to claim that DDT causes liver cancer, blindness, brain damage and kidney failure and he states that DDT will be mixed with benzene, ethanol, chloroform or petroleum.

None of these statements have any basis in fact or reality; these are pure lies and fabrications that Lukyamuzi is using in a transparent attempt to broaden his political support. Unfortunately these lies have consequences; one being that the residents of Munyonyo refused the spraymen access to their houses. For instance, some residents feared that the spraying would cause sterility and other health problems, while there is no evidence for this fear.

Similar examples of malicious and misleading statements by political or religious leaders have hampered and harmed polio vaccination programs in Nigeria. Recently a de-worming exercise in Ghana was severely affected because rumors spread that the medicine was killing children, as opposed to ridding them of harmful parasites.

Carlos Odora, AFM Fellow in Uganda, visited the area shortly after the spraymen were refused entry. Many residents cited the claims that Lukyamuzi and others have raised as the reason to stop the spraymen. Such action harms malaria control and can cost lives, particularly considering the fact that malaria accounts for deaths of children under age five than any other disease in Uganda.

Following some improved outreach and communication by Balton, residents were more reassured and subsequently did allow spraymen to enter their houses, however this incidence raises some important points.

1. The words and actions of politicians and environmentalist groups have consequences and very often they are harmful and highly damaging to malaria control and public health.

2. The Government of Uganda and healthcare advocacy groups should consider legal action against individuals such as Ken Lukyamuzi as the misinformation and lies that they have spread have cost Uganda's taxpayers and private companies money and have potentially endangered lives.
 
3. A knowledge, attitude and practice survey should be conducted in all new areas where IRS is considered to establish the communities knowledge on malaria. Once the level of understanding amongst the communities is established, a focused information, education and communication campaign can be launched to address any misunderstanding before spraying commences.

4. It is vital to involve community leaders in the planning of an IRS program and by evolving the leaders trust is built between the malaria control program and the communities.

5. Community leaders and health authorities should inform community members well in advance of spraying. Increased communication between communities and authorities ensures effective IRS.

6. Any spraying team, whether a private contractor or directly through the Ministry of Health, must engage in thorough and clear information, education and communication programs prior to spraying.

7. Spraymen should ideally be recruited from the local area so that they are both known and trusted by the homeowners and/or know the local language and customs. There are few people that will readily open their houses to complete strangers, particularly if they have not been informed about the purpose of the spraying in advance.

8. Education programs are needed to explain the important difference between the chemicals used and to educate people about what IRS is and why the Ministry of Health conducts a spraying program.

9. Continuous communication with the local communities during and after IRS is important to ensure effective IRS.

10. When used in malaria control, DDT is extremely safe for spraymen and for residents and there are no data or evidence to suggest that it would harm residents; on the contrary, it has probably saved more lives than any other chemical and is a hero in the fight against malaria. These messages must be communicated clearly and consistently though credible sources to the people of Uganda. The current state of understanding will only harm malaria control in the long run and will cost lives.