How male mosquitoes that shoot blanks hold the key to curbing malaria
The sterile insect technique has been piloted against mosquito vectors of the Zika and yellow fever, but not for malaria control efforts
SA is one of four Southern African countries aiming to eliminate malaria transmission by 2023. Indoor residual spraying using DDT and pyrethroid insecticides constitutes the backbone of SAs malaria control programmes.
Effective vector control by indoor residual spraying has been key in the reduction of malaria cases. This was instrumental in creating malaria-free zones in most parts of the country. Malaria transmission is now limited to the northeastern parts of Limpopo, the low-veld areas of Mpumalanga and the far northern parts of KwaZulu-Natal.
Despite a concerted effort to eliminate malaria in these provinces, transmission has remained steady over the past decade.
Failure to eliminate malaria transmission is attributed, in part, to resistance to the insecticides being used. Added to this is the challenge of controlling the outdoor-biting Anopheles arabiensis population that’s largely considered responsible for most malaria transmission in the country. Indoor spraying isn’t completely effective against this mosquito because it mainly targets indoor biting and resting mosquitoes. This strategy is not adequate against vectors that sometimes feed and rest outdoors, such as An. arabiensis. Other, complementary vector control strategies are needed to eliminate the disease. These must be able to control outdoor feeding and resting mosquito populations. One possible approach is a technique that involves sterilising the insects. The technology is currently being assessed in SA. The technique involves a genetic birth control method in which laboratory mass-produced sterile male insects are released into the wild at a ratio that effectively inundates a ...