Isolation of Hendra virus from pteropid bats: a natural reservoir of Hendra virus

Since it was first described in Australia in 1994, Hendra virus (HeV) has c aused two outbreaks of fatal disease in horses and humans, and an isolated fatal horse case. Our preliminary studies revealed a high prevalence of neu tralizing antibodies to HeV in bats of the genus Pteropus, but it was uncle ar whether this was due to infection with HeV or a related virus. We develo ped the hypothesis that HeV excretion from bats might be related to the bir thing process and we targeted the reproductive tract for virus isolation. T hree virus isolates were obtained from the uterine fluid and a pool of foet al lung and liver from one grey-headed flying-fox (Pteropus poliocephalus), and from the foetal lung of one black flying-fox (P. alecto). Antigenicall y, these isolates appeared to be closely related to HeV, returning positive results on immunofluorescent antibody staining and constant-serum varying- virus neutralization tests. Using an HeV-specific oligonucleotide primer pa ir, genomic sequences of the isolates were amplified. Sequencing of 200 nuc leotides in the matrix gene identified that these three isolates were ident ical to HeV. Isolations were confirmed after RNA extracted from original ma terial was positive for HeV RNA when screened on an HeV Taqman assay. The i solation of HeV from pteropid bats corroborates our earlier serological and epidemiological evidence that they are a natural reservoir host of the vir us.