Replication and dissemination of Rift Valley fever virus in Culex pipiens.
Following ingestion of 10(4.2) to 10(7.2) plaque-forming units (PFU) of Rift Valley fever (RVF) virus, 662 of 850 female Culex pipiens (78%) became infected. Those mosquitoes that became infected separated into two distinct groups: 1) those with a nondisseminated infection limited to the gut, and 2) those with a disseminated infection. The former group contained a median of 10(3.2) PFU, while those females with a disseminated infection contained a median of 10(5.5) PFU. Only those females with a disseminated infection were capable of transmitting virus by bite to a susceptible hamster. This is consistent with a mesenteronal escape barrier to viral dissemination. Following intrathoracic inoculation of RVF virus, all females developed a disseminated infection (26/26) and successfully transmitted virus by bite (49/49) if allowed to feed on a susceptible hamster or suckling mouse. Examination of legs and bodies separately provided a rapid and efficient method of determining dissemination status.
D000818:Animals; D002043:Bunyaviridae / Q000502:physiology*; D006224:Cricetinae; D003465:Culex / Q000382:microbiology*; D005260:Female; D007303:Insect Vectors / Q000382:microbiology; D008647:Mesocricetus; D012295:Rift Valley Fever / Q000635:transmission; D012296:Rift Valley fever virus / Q000254:growth & development / Q000502:physiology*; D014779:Virus Replication