[From the archives; originally published November 18, 2005]
Malaria is one of the world’s leading infectious killers. World-wide, almost 40% of the world’s population is at risk of acquiring this disease–many of them in poor countries with limited resources to control the disease. Each year, malaria causes 300-500 million infections, and up to 3 million deaths–about 5000 Africans die of the disease every day; one child succumbs every 30 seconds. Mosquito-borne, simple devices (such as mosquito nets over beds) have been shown to drastically decrease the incidence of disease. Though these only cost a few dollars each, many in developing countries lack the resources to purchase them. Additionally, evolution, as we often see, has caused both the parasites that cause the disease (one of four species of Plasmodium) and the mosquitoes that transmit it (Anopheles species) to become resistant to our efforts to stop them. The parasites have developed high levels of resistance to many of the anti-malarial drugs, and many insecticides are of little use in controlling the mosquito population due to a similar phenomenon.
Continue reading “New malaria vaccine shows promise”
Like a Saturday roundup, but a day delayed. Some other topics I found interesting this week, but didn’t have a chance to elaborate on…
Continue reading “Sunday roundup”
Yesterday, as mentioned previously, was Dunk Malaria day. I’m on the road today in cold ‘n’ gloomy Atlanta so pardon the delay, but coturnix has a collection of posts here regarding the topic. Just spent much of the morning hearing about new strategies to control vectors (aimed mostly at dengue, but some ideas could extend to malaria as well) and learning about new malaria drugs (and resistance to old ones), so perhaps I’ll be able to put up an overview later in the week. I’m away until Friday, so blogging this week will likely be rather sporadic.
Tim Lambert over at Deltoid notes Dunk malaria day is coming up this Sunday, and has offered to match donations (up to $300 total) readers make to The Global Fund to fight AIDS, TB, and malaria. Very cool–I’m kicking in a few bucks for a good cause–if you do the same, drop a line at Tim’s blog.
Malaria is one of mankind’s oldest known killers, with descriptions of the disease dating back almost 5000 years. Each year, malaria causes 300-500 million infections, and up to 3 million deaths–about 5000 Africans die of the disease every day; one child succumbs every 30 seconds. The disease is caused by a number of species of the Plasmodium genus. (In humans, malaria is almost always caused by one of four species: Plasmodium vivax, Plasmodium ovale, Plasmodium falciparum, and Plasmodium malariae, with P. falciparum causing the most severe disease). Unlike many pathogens I discuss on here, Plasmodium is a protozoan–a eukaroyte with a nucleus, like you and I. It also has a very complex life cycle, going through different stages in its mosquito and vertebrate host. (I presented a short overview of this previously in this post on potential malarial vaccines). Though vaccines may be available in the future, prevention today is largely via control of the mosquito vectors using insecticides and mosquito netting. However, mosquitoes are growing increasingly resistant to the insecticides, and many people living in at-risk areas lack the financial means to purchase bed nets.
There are anti-malarial drugs to treat the patient once they’ve already been infected, but these, too, are losing their effectiveness due to parasite evolution. Additionally, a single infection does not confer life-long immunity. Not only can an individual be infected with different species of Plasmodium, but the parasite can switch the antigens it presents–the proteins on the parasite surface that the immune system recognizes. A recent study published in the journal Nature sheds some light on just how P. falciparum switches these antigens.
Continue reading “Mechanism of malaria “hide and seek” coming into view”