This blog is intended to go along with Population: An Introduction to Concepts and Issues, by John R. Weeks, published by Cengage Learning. The latest edition is the 12th (it came out in 2015), but this blog is meant to complement any edition of the book by showing the way in which demographic issues are regularly in the news.

If you are a user of my textbook and would like to suggest a blog post idea, please email me at: john.weeks@sdsu.edu

Wednesday, October 11, 2017

Will Malaria Ever Be Gone From Africa?

Malaria has been one of the biggest killers of humans over the centuries, and an enormous amount of international effort has gone toward eradicating the parasites and the mosquitos that carry the parasite from one victim to another from the earth. The mosquitos (the vectors) flourish especially in warm, wet weather, so it is the mid-latitudes in which malaria is most prevalent, as you can see from the map below:



The most deadly of those parasites is the Plasmodium falciparum, which is prevalent in sub-Saharan Africa. There is probably no researcher in the world who has done more to track and map malaria than Robert Snow at Oxford University, and in the latest issue of Nature, he and his colleagues have traced the spatial spread of malaria across the face of Africa for the past 100 years. Take a look at the map below and see if you can spot a trend:

The change over time is, sadly, not so obvious, as Snow and his colleagues discuss:
The reduction in malaria transmission intensity has not occurred equally between countries or within countries (Fig. 1)[see above], with more substantive declines and ‘shrinking of the map’ occurring at the margins of the historical range of P. falciparum transmission than in the heartland of Africa’s most efficient vector species, Anopheles gambiae sensu stricto and Anopheles coluzzii. This heartland forms a densely populated belt from West Africa through Central Africa toward Mozambique, and represents the most severely impacted area of the contemporary malaria-endemic world: it was ignored after 196017, 18 and risks being ignored today19. Our previous and current armoury of interventions has not eliminated malaria in this part of the world, and there is little indication that it will do so in the foreseeable future.
The take-away here is that we cannot be complacent. There is a lot of work to do to dramatically lower malaria rates in Africa and we cannot stop trying. 

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