Arboviruses of Australia

Summary This paper summarizes the isolation of arboviruses from mosquitoes collected in the Ord Valley between 1972 and 1976. A total of one hundred and ninety five strains of at least fifteen antigenically distinct viruses have been isolated. Seven of these isolates appear to be ‘new’ antigenic types, and several are undergoing further testing. These are three new rhabdoviruses (Kununurra [OR194], a virus provisionally named Kimberley [OR250] and OR189 [provisionally named Parry's Creek]), three ungrouped, non‐haemagglutinating viruses (OR379, OR512, OR869) and a virus (OR540) which reacts to Poly Anopheles A world grouping fluid. The remaining viruses have been previously identified in Australia. These include Murray Valley encephalitis (MVE), Kunjin, Kokobera, Sindbis, Koongol, Wongal, Wongorr and a virus in the Corriparta serological group. The most important finding of these studies is that MVE displays an annually recurrent pattern of activity with a peak seasonal transmission rate at the end of the wet monsoon. This is the first definition of a probable endemic focus of MVE activity in Australia. The major vector for the majority of the viruses isolated was, by inference, Culex annulirostris. However, Aedeomyia catasticta was implicated as a major vector of the Corriparta group virus.

Section: (B) Virus Isolationmentioning

confidence: 99%

“…Most of these virus types have been repeatedly isolated. Seven (MVE, Kunjin, Kokobera, Sindbis, Koongol, Wongal, Wongorr) have previously been isolated elsewhere in Australia (Doherty, 1972(Doherty, , 1977 and seven appear to be 'new'. These 'new' viruses include the three rhabdovirusesKimberley, Kununurra and Parry's Creek.…”

Section: (B) Virus Isolationmentioning

confidence: 99%

Isolation of Murray Valley Encephalitis Virus and Other Arboviruses in the Ord River Valley 1972–1976

Anderson

Stanley

et al. 1981

“…MVE virus was active in New South Wales early in 1971 and 1974 (Dohert\-et at, 1972;Gard et ai, 1976), but virus infection was not reported in 1972 nor 1973. The demonstration of probable aetivity of MVE virus in 1971MVE virus in -1972MVE virus in and in 1972MVE virus in -1973 (Tables 1 and 2) was not expected, even though Kimjin and Sindbis viruses, which probably have similar life cycles to MVE, involving birds and Culex aniiulirostris mosquitoes (Doherty, 1972) were recovered from mosfiuitoes collected in Western New South Wales in April, 1973 (I. D. Marsliull, personal communication).…”

Section: Card Giles Dwyer-gray Axd Woodroofementioning

confidence: 99%

Serological Evidence of Inter‐epidemic Infection of Feral Pigs in New South Wales With Murray Valley Encephalitis Virus

Gp¹,

Giles²,

Dwyer-Gray³

et al. 1976

Summary The sera of 617 feral pigs, collected from three widely separated areas of northern and central New South Wales, were examined for antibody to Murray Valley encephalitis (MVE) virus and to Ross River virus. Haemagglutination‐inhibition (HI) antibody was detected to MVE in 58% of sera and to Ross River virus in 15% of sera. Neutralization tests suggested that the MVE HI antibody resulted from infection with MVE virus in the summers of 1971–1972 and 1972–1973 when the virus was not known to he active in New South Wales. These same tests suggested that more than one flavivirus infected the feral pigs in the summer of 1973–1974 and that Kunjin virus was active in the summer of 1975–1976.

“…However, it is interesting that the single isolate of RRV was collected within the town limits, adjacent to the tidal saltllats which form limited breeding habitats for Ae. vigiiax, a major vector of Ross River virus (Doherty, 1972). Although a large proportion of the lower Ord drainage is tidal mudflats, only a few collections have sampled the mosquitoes of this habitat in the course of the Ord valley studies (Liehne et al, 1976b;Wright, 1981).…”

Section: (B) Virus Isolationmentioning

confidence: 99%

A Preliminary Investigation of the Ecology of Arboviruses in the Derby Area of the Kimberley Region, Western Australia

Wright

Anderson

Stanley

et al. 1981

Summary A survey of mosquito populations in the Derby area of the Kimberley region, Western Australia, in March/April of 1977 yielded a total of 3,318 adult female mosquitoes. Fifteen taxa were represented, seven being new locality records for this area. Culex annulirostris was the dominant species, comprising 85·41% of the total catch. All mosquitoes collected were processed for virus isolation and thirteen strains of four (and possibly five) distinct arboviruses were obtained, all from pools of Culex annulirostris. These viruses include Murray Valley encephalitis, Ross River, Wongal, an untyped non‐haemagglutinating member of the Koongol group and a virus which reacts to polyvalent antisera against the Anopheles A and B groups. With the exception of Ross River, all these viruses had been previously isolated from the Ord River Valley, some 500 km to the north‐east. Comparison of virus isolations in the Ord Valley and Derby supports the suggestion that both sites share a common viral flora. Both also display an exceeedingly high overall isolation rate (approximately 20% for Cx. annulirostris pools). Such comparisons suggest that a number of arboviruses transmitted by Cx. annulirostris are active throughout the Kimberley region and have peak isolation rates at the end of the wet season. Further studies are needed to fully define these viral cycles.