The MalariaWorld Journal

Solomon Islands is a malarious nation in the Pacific with all four human Plasmodium species present. Although chloroquine prophylaxis is recommended for pregnant women, itseffectiveness is uncertain because of chloroquine resistance. A parallel-group, open label, individually randomised superiority trial comparing weekly chloroquine prophylaxis (CQ) with intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine (SP) was conducted among pregnant women aged 15 to 49 years between August 2009- June 2010. The study shows that the use of SP for IPTp is not suitable for prevention of malaria in pregnancy in Solomon Islands, given the low malaria prevalence and the possible high prevalence of sulfa-allergy. Scaling up of transmission-reducing interventions has probably contributed to the malaria reduction in Honiara.

This GCE project set out to develop a novel way of controlling malaria-transmitting mosquitoes by deploying live, insect-eating plants around houses and in mosquito breeding sites. Field surveys were undertaken to collect and identify carnivorous plants. Aldrovanda vesiculosa and Utricularia reflexa were collected from swamps in various locations in Uganda and brought to the laboratory where they were kept in distilled water into which larvae of Anopeheles gambiae were introduced and the impact of the plants studied.

To supplement current malaria prevention methods, and accelerate efforts towards elimination, this GCE project explores the use of outdoor mosquito control devices that mimic real humans, to attract and kill disease-transmitting vectors on a sustained basis. The idea (as envisioned in a GCE Phase I grant (2009) and Phase II grant (2011)) is to lure female Anopheles mosquitoes onto these outdoor ‘pseudo-hosts’, when positioned at optimally selected sites within or around human settlements, and then either trap these mosquitoes, contaminate them with substances that reduce their survival and ability to transmit disease or kill them instantly or within a few days after contact with the devices, thereby reducing exposure to mosquito bites and mosquito-borne pathogens.

This GCE project explored an RNAi strategy to control mosquitoes and prevent spread of mosquito-borne diseases. The strategy involved delivery of double-stranded RNA(dsRNA) elements to mosquito larvae using unicellular, transgenic algae as vectors. Significantly, microorganisms, including microalgae, are the primary source of nutrition for mosquito larvae in water bodies that serve as the breeding grounds for mosquitoes. This strategy of delivering RNA elements to suppress essential target genes in mosquito larvae has many potential advantages over existing technologies.