Mosquitoes potential vectors of canine heartworm in the Northeast Region from Brazil

Introduction In some coastal districts of Sao Luis, capital of the state of Maranhao, Brazil, the prevalence of Dirofilaria immitis is more than 40% i n house dogs. Natural potential vectors, as found in other areas of Northea stern Brazil, are unknown. The nim of this study was to identify probable v ectors of the disease. Methods Mosquito catches were performed at a coastal, district Olho d'Agua, in S. Luis, to look for local potential vectors. Captures were carried out monthly from March 1996 to May 1997, outdoors, having a man and a clog as baits. Mosquitoes were dissected for D. immitis larvae. Results A total of 1,738 mosquitoes belonging to II species were collected Culex quinquefasciatus, the only species collected every month, was more fr equently in the dry season. It accounted for 54.5% of the total, followed b y Aedes albopictus (20.3%), Ae. scapularis (11%) and Ae. taeniorhynchus (11 %). D. immitis larvae were detected in 0.1% of the Cx. quinquefasciatus dis sected (L3 in the Malpighian tubules)and 0.5% of the Ae, taeniorhynchus (L2 in the Malpighian tubules). Conclusion Ae. taeniorhynchus and Cx. quinquefasciatus are considered natur al potential vectors of the canine heartworm Bz Sao Luis. The role of Cx. q uinquefasciatus ns primary vector of D. immitis, however, needs further eva luation.