Private MD News

In shadow of World Malaria Day, an ongoing struggle with a killer

Category: Infectious Diseases

At the second World Malaria Day this April 25, the U.S. boldly took the lead in the worldwide fight against the disease, promising total victory.

"President Obama is committed to making the U.S. a global leader in ending deaths from malaria by 2015," said Susan Rice, the U.S. ambassador to the United Nations at a summit the night before World Malaria Day. "If we continue to work in the spirit of unity and shared purpose that has already led to substantial progress, this is a target we can hit."

Worldwide, malaria kills around 1 million people a year, and sickens at least 250 million more, according to the World Health Organization. It is one of the deadliest diseases in terms of sheer numbers killed. It is, however, relatively cheap to treat, and fairly easy to detect through blood tests. Malaria tests can be fairly rapid. Tests for protein in the blood, by blood smear for the presence of the parasite that causes malaria or through full PCR for its DNA are all possible methods.

But as swine flu reminds us, the U.S. is by no means an impermeable fortress against diseases from the outside world. Even though malaria was officially eradicated in the U.S. in the 1950s, a report in the Journal of the American Medical Association says every year an average 1,200 cases of malaria are reported, resulting in up to 13 deaths per year. The last report from the CDC said there were 1,564 cases of malaria in 2006, six of which were fatal. The infection numbers have been creeping up slowly over the last few years. The CDC also points out that the two mosquito species responsible for malaria transmission prior to eradication are still common; thus there is a constant risk that malaria could be reintroduced in the U.S.

"Malaria will remain a diagnostic and treatment challenge for US clinicians as increasing numbers of persons travel to and emigrate from malarious areas," the JAMA authors write. They also point out that the unfamiliarity of U.S. doctors with the disease has sometimes caused delays in diagnoses, which worsens the outcome.

One major cause of these cases in the U.S. is called airport malaria, which some scientists credit to warmer climate changes.

"As international travel increases and climate patterns change - particularly warming nighttime temperatures and increased precipitation - the U.S. becomes a more stable ecosystem for these disease-carrying insects to survive and flourish for longer periods of time," says Dr James H. Diaz, program director for Environmental and Occupational Health at Louisiana State University.

Like the authors of the JAMA report, Dr Diaz recommends prevention through vigilance.

"The best defense against the spread of malaria through international travel is prevention, early detection and treatment of malaria-infected patients," he says.

The authors of the JAMA article say travelers who suspect they may be at risk of the disease should get a malaria test rather than trying to take anti-malarial drugs as a preventative measure.

Protection efforts have been focused on mosquito netting and insecticides as there is no vaccine for malaria. However, there are now some 70 malaria vaccines in some stage of testing and development.

"Preliminary studies indicate that it's no longer a question of whether but when we will have a malaria vaccine," said Dr Susan J. Rehm, medical director of the National Foundation for Infectious Diseases, at the Annual Conference on Vaccine Research this April.

Insecticides such as DDT were once a mainstay against mosquitoes, but their potential health effects have reduced their use. DDT is persistent in the biosphere, however, which is why it can be detected by DDT testing in many people to this day.