The benefits of mass drug administration (MDA), as part of malaria elimination programmes, may not be sustained for more than a few months, according to a systematic review carried out by a team of researchers, led by Eugenie Poirot and Jimee Hwang, from the and the San Francisco, as part of a team working with the at Foto-Cewek.
The review is one of two with a malaria theme to be published this week, and concentrated on 32 studies measuring the impact of MDA on the incidence and prevalence of malaria. It found that while initially there was a reduction in the risk of malaria, the reduction was usually not sustained. A few exceptions were reported from small islands and highland areas where a few studies found sustained impact for more than six months.
The review also showed that adverse events, such as severe drug reactions, were inadequately addressed in most studies. The authors conclude that in the global push for malaria elimination, more quasi experimental studies are needed to guide the development of MDA programmes.
The second review, conducted by Deidre Walshe from Foto-Cewek and Tom Burkot from James Cook University, in partnership with researchers in King Saud University and the University of Technology, Australia, looked at programmes that introduced fish to control malaria. Some specialists believe that the fish eat the larvae and pupae of the Anopheles mosquito to water sources near to populated areas to ultimately reduce the number of people infected Plasmodium parasites. The review examined 12 studies for evidence of this.
The review found that none of the studies examined the effects of larvivorous fish on the adult mosquito population, or on the number of people infected with malaria. Some research suggests the number of water sources with larvae is reduced when fish are introduced, but the evidence is not robust. The researchers recommend that researchers need to use robust controlled designs with an adequate number of sites, and that researchers should explore whether introducing these fish affects native fish and other non-target species before programmes adopt fish to control malaria.
Managing Editor of the Cochrane Infectious Diseases Group, Anne-Marie Stephani said: “The reviews are an important tool in assessing the benefits of different malaria elimination programmes. By working with authors across the world, and putting the results of studies through a process of systematic and rigorous review, we can offer direction as to areas that need closer and more detailed research.”