‘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.