Successful field trial of attractive toxic sugar bait (ATSB) plant-spraying methods against malaria vectors in the Anopheles gambiae complex in Mali, West Africa.

BACKGROUND: Based on highly successful demonstrations in Israel that attractive toxic sugar bait (ATSB) methods can decimate local populations of mosquitoes, this study determined the effectiveness of ATSB methods for malaria vector control in the semi-arid Bandiagara District of Mali, West Africa. METHODS: Control and treatment sites, selected along a road that connects villages, contained man-made ponds that were the primary larval habitats of Anopheles gambiae and Anopheles arabiensis. Guava and honey melons, two local fruits shown to be attractive to An. gambiae s.l., were used to prepare solutions of Attractive Sugar Bait (ASB) and ATSB that additionally contained boric acid as an oral insecticide. Both included a color dye marker to facilitate determination of mosquitoes feeding on the solutions. The trial was conducted over a 38-day period, using CDC light traps to monitor mosquito populations. On day 8, ASB solution in the control site and ATSB solution in the treatment site were sprayed using a hand-pump on patches of vegetation. Samples of female mosquitoes were age-graded to determine the impact of ATSB treatment on vector longevity. RESULTS: Immediately after spraying ATSB in the treatment site, the relative abundance of female and male An. gambiae s.l. declined about 90% from pre-treatment levels and remained low. In the treatment site, most females remaining after ATSB treatment had not completed a single gonotrophic cycle, and only 6% had completed three or more gonotrophic cycles compared with 37% pre-treatment. In the control site sprayed with ASB (without toxin), the proportion of females completing three or more gonotrophic cycles increased from 28.5% pre-treatment to 47.5% post-treatment. In the control site, detection of dye marker in over half of the females and males provided direct evidence that the mosquitoes were feeding on the sprayed solutions. CONCLUSION: This study in Mali shows that even a single application of ATSB can substantially decrease malaria vector population densities and longevity. It is likely that ATSB methods can be used as a new powerful tool for the control of malaria vectors, particularly since this approach is highly effective for mosquito control, technologically simple, inexpensive, and environmentally safe.

Spatial analysis of malaria transmission parameters in the rice cultivation area of Office du Niger, Mali.

The effects of rice growth environment on malaria transmission, taking into account spatial correlation, were assessed in the Office du Niger, Mali. Between April 1999 to January 2001, 8 quarterly entomologic surveys were conducted in 18 villages in 3 agricultural zones. Vector densities in sleeping houses were related to rice crop, rice development stages, vegetation abundance, water state, and seasons. They were high throughout the rice-growing seasons, increased as the rice crop developed, and decreased as vegetation became abundant. They also showed large spatial correlations (up to 30.6 km). The vectorial capacity exhibited both seasonal and village-to-village variation. Parity and the human blood index were weakly related to adult densities and showed low spatial correlations (up to 3.4 km), which suggested that small area variation in malaria transmission results mainly from variations in vector-human contact. Control strategies in rice cultivation areas should pay attention to this local variation.

A national teleradiology programme in Mali: implementation and results.

We reviewed the national teleradiology programme in Mali to establish whether it improved diagnosis for patients and improved the referring doctor's ability to give an accurate diagnosis. The teleradiology programme connected the University Hospital in Bamako to all seven regional hospitals in Mali and one private health clinic. The pilot phase began in 2005 in three hospitals. Initially the implementation involved connections via broadband, but subsequently satellite antennae were provided at three remote hospitals in the north. Between 2005 and 2013, X-ray and mammogram images from 5628 patients were read by teleradiology. Radiologists provided the sole diagnosis for 29% of cases (i.e. the referrer did not make a diagnosis) and altered the regional doctor's diagnosis in 12% of cases. The proportion of cases for which the regional doctor gave no diagnosis decreased from 93% to 24% over the same period, indicating an increase in the doctors' confidence and incentive to test their own diagnosis. The percentage of cases for which regional doctors made an inaccurate diagnosis decreased to 3% in 2013. Use of the teleradiology service varied widely between hospitals. Successful implementation depended on local ownership of a network, which was developed in close collaboration with hospital leadership, national radiologists and other healthcare personnel.