03 September 2010

Progress On Malaria

A new drug to treat malaria that works in a different way than earlier drugs has worked with a single dose to cure malaria in a mouse model and is headed for human trials soon. It was developed with simple brute force, Edison style, by testing twelve thousand natural chemicals over three years to see if they worked to treat malaria, until they found one that worked.

This is good news because Southeast Asian strains of the disease are developing resistance to existing drugs, including artemisinin, the last widely effective malaria drug. Progress in fighting malaria has been made, never the less, with "wider use of insecticides and bed nets to ward off mosquitoes that carry the disease."

[A]rtemisinin . . . is the mainstay of combination therapy for as many as 100 million patients world-wide. Resistance has already rendered some older therapies less effective. . . . The malaria parasite can cause fever, joint pain and death. Last year, there were an estimated 240 million cases of malaria. Of total deaths, 91% occurred in Africa and 85% were children under the age of five . . . . In 2009, malaria deaths world-wide fell to 836,000 from more than one million a few years earlier, including declines in Eritrea, Rwanda, Zambia and Zanzibar. Over the past decade, malaria cases have fallen in nine countries in Africa and in 29 elsewhere.

Malaria is the third deadliest infectious disease that kills young people in the world after AIDS and tuberculosis. "Malaria was almost eradicated 30 years ago; now it is on the rise again."

General measures to prevent diseases spread by flying insects make sense in Africa and tropical Asia, however, even if new drugs can be effective against malaria. These include: African Trypanosomiasis (“sleeping sickness”), which is spread by the tsetse fly; dengue fever, spread through the bite of the Aedes aegypti mosquito; leishmaniasis, a disease spread by the bite of the sandfly; and Japanese encephalitis, a highly lethal mosquito-borne disease endemic in Asia.

Influenza is a major infectious disease killer as well (not generally via insect bites), but like deaths from accidental falls and pneumonia, predominantly kills those who are elderly, and to a lesser extent, younger people who have compromised immune systems. Thus, while it is a common proximate cause of death, it is generally only fatal in people who are especially vulnerable to it for some other reason.

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