Passage of Ingested Mansonella ozzardi (Spirurida: Onchocercideae) Microfilariae Through the Midgut of Aedes aegypti (Diptera: Culicidae)
ARMY MEDICAL RESEARCH INST OF INFECTIOUS DISEASES FORT DETRICK MD
Pagination or Media Count:
When virus and microfilariae are ingested concurrently by a mosquito, microfilariae mf may penetrate the mosquito midgut and introduce virus directly into the mosquito hemocoel, allowing mosquitoes to become infectious much sooner than normal and enhancing transmission of viruses by mosquitoes. Mansonella ozzardi Manson is a benign filarial nematode parasite of humans in Latin America and is transmitted by black flies Diptera Simuliidae and biting midges Diptera Ceratopogonidae. Because M. ozzardi and dengue are sympatric, we wanted to know whether M. ozzardi mf had the ability to penetrate the midgut of Aedes aegypti L. Diptera Culicidae and thus play a potential role in the enhancement of dengue transmission. To test this, the F1 progeny from locally collected Ae. aegypti were fed on M. ozzardi-infected human males in an endemic village in northern Trinidad. Mosquitoes were dissected at various times after feeding and examined for mf in the midguts and thoraces. Microfilariae penetrated the midguts of 43 of 63 mosquitoes that ingested mf. Overall, 11 of mf penetrated the midgut by 17 h after being ingested. The intensity of midgut penetration was positively correlated to the numbers of mf ingested. Because midgut penetration is a key requirement for mf enhancement to occur, the potential exists that M. ozzardi could be involved in the enhancement of dengue virus transmission.
- Medicine and Medical Research