The mosquito dunk (Bacillus thuringensis israelienses) as a control agent against mosquito larvae in Khartoum State, Sudan Abdalmagi

Background: During the mid-1970s, larvicides have become available that are highly effective, yet selective in action, and therefore environmentally safe to non-target organisms, as well as for human exposure(1). Objectives: The small field trial was carried out from 12th of January to 16th of February 2008 in Khartoum State to evaluate the efficacy and persistence mosquito dunk® (Bti) against mosquito larvae and to measure the effect of physic-chemical properties on mosquito dunk. Material & Methods: The efficacy and persistence of Bacillus thuringiensis subspecies israelensis (mosquito dunk®) as a biological control agent against mosquito larvae was conducted in Khartoum State. Twelve ponds were used as natural breeding habitats of mosquitoes; six of them were treated with dunk at a rate of 1 dunk per 100 square feet and six ponds left untreated (control). Results: The study revealed that more than 80% reduction in immature stages density was observed up to 5, 3 and 2 weeks for the 3rd, 2nd and 4th instars of Anopheline spp., respectively. However, the study showed that the mosquito dunk was noteffective (under 80% mortality) against 1st, instar larvae and pupae of Anopheline species as well as Culex developmental stages. Conclusion & Interpretations: The dunk was very effective in controlling 3rd and 4th instars of Anopheles spp; for 2 weeks interval. Therefore we propose a surface application regime of once every 2 weeks for mosquito dunk

Malaria control in an urban area: a success story from Khartoum, 1995-2004.

Khartoum is an urban area with low malaria transmission. Early control efforts were successful in reducing the risk but malaria has resurged in recent years. In 2002, the Government of Sudan, with support of the World Health Organization, embarked on an initiative aimed at freeing Khartoum of malaria. The initiative's prevention strategy has focused on larval control interventions. The results indicate a significant reduction in malaria prevalence, confirmed and clinically diagnosed malaria cases among outpatient attendance and the number of malaria-associated deaths. It is proposed information be collected on parity rates and that a sub-sample of the adult mosquito collections be subjected to ELISA or PCR for identification of malaria parasite infections in mosquitoes in areas showing active foci.

Stratification of Khartoum urban area by the risk of malaria transmission.

A cross-sectional community-based study was carried out in Khartoum urban area aimed at stratifying the area by risk of malaria transmission. Two thousand households (8092 individuals) were surveyed during the cold, dry and rainy seasons of 2002. Households with screened windows, using bednets or both were 5.0% (95% CI: 4.1-6.0), 10.9% (95% CI: 9.5-12.3) and 1.8% (95% CI: 1.2-2.5) respectively. Access to health services was high. Only 3.8% (95% CI: 2.9-4.7) of households kept antimalarial drugs at home. The parasite rate, spleen rate and fever rate were very low (0.21%, 0.17% and 0.97% respectively). Overall, people in Greater Bahry suffer a greater burden of malaria than those in Greater Khartoum or Greater Omdurman, with a seasonal pattern of transmission.