Development of Mansonella ozzardi in Simulium amazonicum, S. argentiscutum, and Culicoides insinuatus from Amazonas, Colombia.

Simulium amazonicum, S. argentiscutum and Culicoides insinuatus were collected from the Amazon region of Colombia after having blood-fed on volunteers naturally infected with Mansonella ozzardi. Dissection of the specimens revealed that these species supported the development of the microfilaria of M. ozzardi to the infective stage. Infective larvae were obtained from Simulium within 7 days at temperatures ranging from 23-30 degrees C. S. argentiscutum ingested more microfilariae and had a correspondingly higher experimental infection rate. Three of 31 C. insinuatus dissected beyond day 5 postfeeding contained one advanced second-stage and two third-stage larvae. The current investigation indicates that Culicoides, as well as Simulium, may serve as vectors of mansonelliasis in the Comisaría of Amazonas.