‘For every complex problem there is a solution that is clear, simple, and completely wrong.’ ( H L Mencken. ) Is malaria control an example?
Zambia is an ‘epidemic’ malaria zone. This means that there is very little malaria in the height of the dry season when the relevant mosquito has no stagnant water to breed in. But the annual rains in December to March turn this flat valley into a mosquito paradise, which lasts well into June and July as water collects in pools locked in by the clay soil. As a result the risk of contracting malaria is very high. In this small settlement of 10,000 or so, we are seeing hundreds of cases daily, and the risk to foreigners working here seems to be that one in 5 or 10 will get it in any one year even though they are all aware of the need to prevent the mosquito bites, and all use nets and repellent sprays. Mostly the illness is like an extremely severe flu if treated promptly, but a few cases ( ?5%)become severe and there is a definite mortality rate. Seeing adults with temperatures over 40 is a bit of a shock for a GP from the UK, and personally I am taking preventative drugs!
Worldwide it is estimated that malaria kills roughly half a million people a year, mostly in Africa, and mostly children. Because malaria is a parasite, which gets inside human cells in the blood and the liver, it seems to be able to evade the immune system.
In other areas of the world drainage of wet areas has been very effective in eradicating the mosquito, but this would be impossible here. So malaria control here has focused on insecticidal bednets and ready access to diagnosis and treatment in order to reduce the chance of the mosquito biting an infected patient. This is available from community volunteers in the villages as well as government clinics. According to Bill Gates if we work at it we can eradicate malaria (as we have smallpox). See https://www.gatesnotes.com/Health/Eradicating-Malaria-in-a-Generation
But I have a sneaking suspicion that the main effect of our current efforts is to make this area i.e. the Luangwa valley inhabitable. 40 years ago there were very few people indeed living in this area, and I wonder if one reason might be that the risk of malaria was high and there was no treatment available. Now we have both diagnosis and treatment easily available, and death rates are much lower but we have hugely increased the number of people who are living close to water which is full of anopheles mosquitoes.
So our efforts and those of the Gates foundation are no doubt at all saving huge numbers of lives in the short term. But it looks as if eradication will only happen if there is a real breakthrough in terms of vaccines, insecticides, or mass treatment.