Tuesday, March 11, 2008

Engineering the End of Malaria

In my Feb. 25 entry, I used the idea of wiping out malaria as an example of what might be done with "a few billion dollars" that would otherwise go toward dealing with global warming. I will admit that I simply pulled that number out of the air. Since then I have learned that while eliminating malaria is something that people as wealthy as Bill and Melinda Gates have tried to do, it is by no means a simple or straightforward task. But engineers may be able to help in some ways you wouldn't expect.

As you probably know, people contract malaria from the bite of a certain kind of mosquito that is infected with the protozoan parasite that causes the disease. The parasite hides inside liver cells or red blood cells in its human host, which is one reason that no one has devised an effective vaccine for the disease. Drugs are available to prevent it, but you have to take them all the time, sick or well, and such prophylactic treatment is too expensive for many residents of areas such as Africa where malaria is endemic. So many anti-malaria campaigns in the past have concentrated on eliminating the animal host: the anopheles mosquito that carries the malaria parasite.

The New York Times recently carried a report about whether malaria can be eliminated as smallpox has been. It seems that the consensus of public-health experts is that you can markedly reduce the incidence of malaria through spraying mosquito-infested areas with insecticide, but absolute elimination is an elusive goal at best. In Sri Lanka, for example, systematic spraying programs helped reduce the number of malaria cases from over a million in 1955 to only 18 in 1963. But the government cut back its programs, and malaria came back, reaching a level of over half a million cases in 1968. That lesson finally learned, Sri Lanka started spraying again and hasn't stopped, and the annual rate of malaria cases is now down to a few thousand.

At a 2007 malaria conference, Bill and Melinda Gates challenged public health leaders around the world to eradicate malaria altogether. Their foundation has already spent over a billion dollars fighting malaria, but clearly more than just money will be needed.

One commentator in Scientific American has pointed out that the free mosquito-net programs sponsored by many governments may not be as effective as they could be. Here is one area where engineers can get involved. The classic kind of mosquito net hangs from a string tied to the ceiling and drapes down to the edges of the mattress, protecting the sleeper from night-time mosquito bites, which is when the anopheles variety is active. This is fine as long as you have a mattress for the net to tuck under. But in thousands of villages where a mattress for every family member would be an unheard-of luxury, young children sleep on the ground. There are rectangular frame-type mosquito nets available that will work in this situation, but they aren't as convenient as the single-string type.

This little net problem is an example of how complex the malaria issue is. Even if engineers devised a new type of net that was ideal for the poorest residents, there are a lot of problems that remain. How do you get this net into the hands of those who can use it? How do you persuade them that using it will keep their children healthier? Who pays for all of this, especially if the new net costs more than the old ineffective ones?

In times past, some engineers would have said these issues were not engineering problems. But organizations like Engineers Without Borders (EWB) realize that the hardware or software part of a solution is only a part, and often not the most important part. An effective technical solution to any problem also has to factor in economics, motivation, distribution, education, and so on. EWB is an organization dedicated to providing engineering solutions for disadvantaged communities through sustainable engineering. Through many chapters at universities and colleges with engineering schools, they recruit volunteer students who get a holistic picture of not just a technical problem, but an entire culture and the cultural and social context of the problem as well. Though I never had such an experience in my student days, I think I might have been a very different kind of engineer if I had.

Only time will tell whether the wealth of the Gates Foundation, the ingenuity of engineers, medical researchers, public health officials, and the willingness of affected communities will converge to defeat the old tropical enemy, malaria. For the reasons I've discussed, it is a much harder task than the smallpox battle. But I wish the best for everyone involved.

Sources: The New York Times article on whether malaria can be defeated was carried in the Mar. 4, 2008 online edition at http://www.nytimes.com/2008/03/04/health/04mala.html. Scientific American's article on mosquito-net engineering appeared in the January 2008 issue, available online at http://www.sciam.com/article.cfm?id=a-better-mosquito-net. And Engineers Without Borders-International has a website at http://www.ewb-international.org.

1 comment:

  1. Africa Fighting Malaria12:54 PM, April 22, 2008

    World Malaria Day is April 25, 2008. Africa Fighting Malaria is issuing a Call to Action to support indoor residual spraying, a highly effective, World Health Organization-approved method of malaria control – check out our interactive Africa map: http://fightingmalaria.org/issues.aspx?issue=14

    Also check out our new video and support AFM's fight against malaria! http://fightingmalaria.org/AFMInAction/

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