MECHANICAL TRANSMISSION OF VENEZUELAN EQUINE ENCEPHALOMYELITIS VIRUS BY HEMATOPHAGOUS MITES (ACARI)

Studies were undertaken to determine whether two species of hematophagous mites could transmit Venezuelan equine encephalomyelitis (VEE) virus to suckling mice. The chicken mite, Dermanyssus gallinae (De Geer), mechanically transmitted this virus to previously uninfected mice up to 16 h after taking a blood meal from a viremic animal. In contrast, Laelaps kochi Oudemans failed to transmit virus to mice in any feeding trials. Virus did not replicate in either species of mite but was detected in 20% of D. gallinae and in 12% of L. kochi specimens tested 48 h after a viremic blood meal. In mites inoculated intracoelomically with virus, recovery rates declined over time, but virus was detected up to 7 d later in 5% of D. gallinae and up to 3 d later in 10% of L. kochi. Biological transmission of VEE virus was not demonstrated in either species of mite.