Field assessment of 4-hydroxycoumarin as an attractant for anthropophilic Anopheles spp. vectors of malaria in Madagascar.

Mosquito-borne diseases like malaria are a major public health problem in tropical countries, such as Madagascar. Female Anopheles mosquito vectors the human malaria parasites (Plasmodium spp.) and is important indicator in malaria surveillance activities. Among the various means of vector control in Madagascar, the use of attractants for mass trapping of target species could be an alternative to insecticides. The aim of this study is to evaluate whether 4-hydroxycoumarin can be used as an attractant for anthropophilic Anopheles spp. vectors of malaria. For this, a field study was conducted using CDC light traps in the village of Ambohidray, Madagascar. 16 days of trapping was conducted and four replicates nights were performed for each product tested. 4-hydroxycoumarin, octenol and two types of blend of these products were tested. The results showed that 4-hydroxycoumarin (2 mg) have a significant attractive effect on Anopheles spp. and significant selectivity towards Anopheles gambiae s.l, and Anopheles mascarensis which are both significant malaria vectors in Madagascar. A synergy of 4-hydroxycoumarin with octenol was found to attract these mosquito vectors. A significant decrease in vector populations was observed during this experiment. These results suggest that 4-hydroxycoumarin could be useful for malaria surveillance and the control of vector populations.