This week malaria world featured an interesting article about the ‘collateral damage’ caused by insecticides used against mosquitos and how the effect on nuisance insects is a major reason people continued to use insecticide treated nets. The authors are concerned that the development of resistance by bedbugs and cockroaches to the insecticides usually used on insecticide treated nets was discouraging continued use of these products.
‘Review on the impacts of indoor vector control on domiciliary pests: good intentions challenged by harsh realities’ by Hayes and Schal of North Carolina State University was published by the Royal Society. This review identified 1,248 potential articles and narrowed examination to a final total of 28 peer reviewed articles of most relevance.
They found that recipients of insecticide treated nets and other indoor and outdoor insecticide treatment programmes are more likely to continue their use if they are effective against nuisance insects such as bedbugs, cockroaches and house flies. But as insecticide resistant strains of these pests become more common, they are more likely to discontinue their use.
This suggests that many people in the target countries (including Tanzania, Gambia, Papua New Guinea, Botswana, India, Ethiopia) may value the effect of these insecticides more on reduction of nuisance insects than they do as a prevention of bites by the supposed disease vector mosquitos. They do not seem as concerned with preventing mosquito bites.
If the instinct of the potential victims is ambivalent, again, the question has to asked – why are malaria researchers so convinced that the disease diagnosed as malaria is actually spread by mosquitos? The underlying basis for this belief, the research carried out 120 years ago by Ross, Grassi and others is far from convincing. I refer to my books ‘Malaria is spread by mosquitos?’ and translation of Grassi’s ‘Studies Of A Zoologist About Malaria’ for more information.