THE ROLE OF 4 ANOPHELINE SPECIES (DIPTERA, CULICIDAE) IN MALARIA TRANSMISSION IN COASTAL TANZANIA

Malaria is holoendemic in coastal Tanzania with Anopheles funestus and members of the A. gambiae complex being mainly responsible for transm ission. Over a 4 months' sampling period 2222 anopheline mosquitoes we re collected using light-traps and indoor resting catches, of which 58 .6% were A. gambiae, 7.6% A. arabiensis, 6.9% A. merus and 26.9% A. fu nestus. Plasmodium falciparum circumsporozoite antigen (CSA) rates wer e: A. funestus 6.05% (n=479),A. gambiae 8.4% (n=1042),A. arabiensis 7. 3% (n=136) and A. merus 9.8% (n=122). The P. malariae CSA rate for all anophelines was 0.07% (n=1862). Estimated sporozoite densities were l ess than 2000 for at least 50% of all the positive mosquitoes. Along t he coast the abundance of A. merus (41.3%) and A. gambiae (46.1%) was similar, and their CSA rates were comparable (4.6% and 12.5%, respecti vely) and higher than those for A. arabiensis (7.7%) and A. funestus ( 4.6%). These results indicate that A. merus plays an unexpectedly impo rtant role in malaria transmission in coastal Tanzania.