Mosquito isolates of Ross River virus from Cairns, Queensland, Australia.

Abstract

Abstract. During 1996-1998 60,619 mosquitoes were collected around Cairns, Australia and processed for Alphavirus isolation. Thirty-three isolates of Ross River (RR) virus were made from 9 species, Aedes imprimens, Aedes kochi, Aedes notoscriptus, Aedes vigilax, Culex annulirostris, Culex gelidus, Mansonia septempunctata, Verrallina (formerly Aedes) carmenti, and Verrallina lineatus. Attempts to isolate RR virus from 121 Aedes aegypti were unsuccessful. Twenty-six (79%) of the isolates came from within 1 km of a colony of spectacled flying-foxes, Pteropus conspicillatus. The minimum infection rate for these mosquitoes was 1.0 compared with 0.2 per 1,000 for mosquitoes trapped at all other sites. Ross River virus has not previously been isolated from Ae. imprimens, Cx. gelidus, Ma. septempunctata, Ve. carmenti, or Ve. lineatus. This is also the first isolation of an arbovirus from Cx. gelidus in Australia. In conclusion, the vector status of Ve. carmenti, Ae. aegypti and Ma. septempunctata warrants further study. This study also provides evidence that P. conspicillatus may be a reservoir host.

Land Use Influences Mosquito Communities and Disease Risk on Remote Tropical Islands: A Case Study Using a Novel Sampling Technique

“…52 It is capable of transmitting Ross River fever, Barmah Forest virus, Murray Valley virus, Kunjin virus and Japanese encephalitis virus to humans. 53,54 Culex annulirostris was responsible for the outbreaks of Japanese encephalitis in the Torres Strait in 1995 and 1998, 55,56 and it was also the most dominant species captured in three different tropical habitat types (rainforest, rainforest edge, and grassland) in far north Queensland 57 and from urban, periurban, and melaleuca swamps 45,58 in the same region. Culex annulirostris is regarded as a generalist species with opportunistic feeding patterns defined by host availability and it can use a wide variety of larval habitats including fresh water swamps, shallow grassland pools, and large artificial containers such as livestock watering tanks.…”

Bats as Potential Reservoir Hosts for Vector-Borne Diseases

“…The virus was also isolated from a Pteropus bat in Australia (Doherty et al 1966;Messenger et al 2003). Serological surveys and virus isolation by Harley et al (2000) from mosquitoes trapped near a flying fox camp suggested the flying fox Pteropus conspicillatus as a potential reservoir host. These authors also suggest that other vertebrates living in the flying fox camp could also be important reservoir hosts (Harley et al 2000(Harley et al , 2001.…”

“…Serological surveys and virus isolation by Harley et al (2000) from mosquitoes trapped near a flying fox camp suggested the flying fox Pteropus conspicillatus as a potential reservoir host. These authors also suggest that other vertebrates living in the flying fox camp could also be important reservoir hosts (Harley et al 2000(Harley et al , 2001. On the other hand, Ryan et al (1997) showed that the grey-headed flying fox (Pteropus poliocephalus) does not produce a viraemia of sufficient magnitude to be very competent vertebrate hosts of RRV (Ryan et al 1997).…”

“…camptorhynchus and Cx. annulirostris (Harley et al 2000;Hu et al 2006;Mackenzie et al 1994). There is also evidence that Ae.…”

“…There is also evidence that Ae. aegypti can be infected with and transmit the virus, but it has not been isolated from this species in the field (Harley et al 2000). The Eastern equine encephalitis virus (EEEV) is placed as the only species in the Eastern equine encephalitis complex (EEE) and is distributed in North America (Fig.…”