According to the African Medical and Research Foundation (AMREF), “[m]alaria is the most important parasitic disease in the world. It kills 3,000 children every day and more than one million each year. The majority of these deaths occur among children under five years of age and pregnant women in sub-Saharan Africa.”
In the most recent edition of The Economist magazine, a piece titled “A shift of perspective” documents the research of Dr. Mauro Marrelli and Dr. Chaoyang Li of Johns Hopkins University. The researchers hope that breeding genetically-altered, malarial-resistant parasites and releasing them into wild will help to stem the tide of malarial infections. Drs. Marrelli and Li have found a gene, called SM1, which prevents malaria infections. SM1 is superior to genes which suppress but do not prevent infection since suppressing the infection “imposes a burden on the animal, since materials and energy have to be diverted to the boosted immune system. In practice, such insects are worse off than they would be without the gene. But because SM1 prevents infection rather than suppressing it, Dr Marrelli and Dr Li hoped that different rules might apply.” The mosquitoes with the SM1 gene may be superior (in a Darwinian sense) to those mosquitoes without it and thus more of these malaria-free mosquitoes will survive.
Problems do exist. It is possible that the SM1 gene is helpful only when one copy of the gene is present in a mosquito (and not two). Also, “the type of malarial parasite used in this and many other experiments is not actually one that causes human disease.” Still there is hope that scientific advances could one day rid the world of one of its most deadly parasitic diseases.