Figure 1.

Integrated life cycle of the three Mansonella spp. An infected female blood-sucking arthropod genus Culicoides (A) for all the three Mansonella species, or Simulium (B) only for M. ozzardi] introduces third stage filarial larvae (L3) into the human host. The larvae develop into adult filariae, which commonly reside in the pleural cavity (1); the peritoneal cavity (2) or the subcutaneous dermal layer (3). The female worms produce microfilariae, which are found in peripheral blood (M. perstans and M. ozzardi) or found in the skin (M. ozzardi and M. streptocerca). An arthropod ingests the microfilariae during a blood meal. After ingestion, the microfilariae undergo two molts to become infective L3. The life cycle in which Culicoides vectors are involved can occur both in Latin American and African settings. Simuliid species are known to transmit M. ozzardi in Latin America.