Studies with equine infectious anemia virus: transmission attempts by mosquitoes and survival of virus on vector mouthparts and hypodermic needles, and in mosquito tissue culture.

Biological and mechanical transmission trials with Psorophora columbiae (Dyar and Knab) and Aedes sollicitans (Walker) and ponies acutely infected with equine infectious anemia virus (EIAV) were negative. The EIAV antigen was detected by radioimmunoassay in Ae sollicitans immediately after the mosquitoes had fed on an acutely ill pony, but not 14 days after feeding. Psorophora columbiae mosquitoes had detectable EIAV antigen as determined by radioimmunoassay 24 hours after they fed on an acutely ill pony; this antigen was not detected again until 6 days after feeding and was still detected 14 days after feeding. The EIAV was detected on hypodermic needles held at 25 C for 96 hours, but was not detected 120 hours after the needles were dipped in solutions of EIAV. The virus was detected on the mouthparts of mosquitoes for 1 hour after they had fed on an EIAV-rich medium, but was not detected 4 hours after feeding. Culex pipiens quinquefasciatus Say ovarian cells maintained the infectivity of EIAV for 10 weekly passages, but no evidence for virus multiplication was obtained.