Dr. E . L. French - Symposium Chairman
It is my pleasing duty this morning to welcome you all to the Second Arbovirus Symposium. The first Arbovirus Symposium was held in Brisbane in May 1976 and now in 1979 it is considered timely that we should consider the advances in the knowledge of Arboviruses in Australia that have occurred since 1976 and take a look at future possible developments in the field of human and animal arbovirus research in Australia.
The selection of Brisbane, Queensland, as the venue for the symposia of 1976 and 1979 was very appropriate for a number of reasons. As early as 1906 Bancroft, on the basis of observations made in northern Australia, first suggested that Dengue Fever had as its vector the mosquito Aedes aegypti (Bancroft 1906). Later Cleland et al. (1916, 1918, 1919) proved that Aedes aegypti is an efficient vector of dengue and that Culex fatigans is not.
In 1917-1918 the first cases of Australian X disease were described in Queensland by Breinl (1917, 1918) who considered this mystery disease to be an aberrant form of Poliomyelitis. It was the work of public health doctors from NSW that showed this disease to be distinct from classical Poliomyelitis and they successfully transmitted the virus to sheep, a horse and a calf (Cleland et al. 1918. Much later work in Melbourne and Adelaide showed that this first arbovirus of man to be isolated in the laboratory was probably identical to the Murray Valley Encephalitis (MVE) virus isolated in 1951 from outbreaks of severe encephalitis along the waterways of eastern and southern Australia (Miles et al. 1951; French 1952 ; McLean et al. 1954; Anderson 1954).
The outstanding contributions made to our understanding of arbovirus natural history in Australia by the Queensland Institute of Medical Research from about 1955 onwards would be well known to you all. Dr. Ralph Doherty and his colleagues over the years studied some 30 or more arboviruses they isolated, and have made the Queensland laboratory one of the leading arbovirus centres for arbovirus research in the world. The work of other groups in Canberra and Western Australia on MVE will also be prominent in our discussions on this and other arboviruses at this Symposium.
In 1968 the CSIRO Animal Health Division decided to establish a unit for the study of virus diseases of livestock in northern Australia. Mr. Toby St. George, a veterinary virologist from the Parkville Laboratory of that Division, was transferred to the Long Pocket Laboratories of the Division in Queensland. He quickly established his laboratory and a series of sentinel herds in various parts of northern and eastern Australia, and he monitored these herds for virus diseases known to cause morbidity in cattle and sheep. It was very much in the minds of the Chief of the Division of that time, and his senior virologists and entomologists, that information collected by the units in Brisbane, Sydney and Melbourne on arboviruses and their vectors could prove to be vital in the event of the introduction of a n exotic arthropod-borne disease of livestock. Indeed, the whole genesis of veterinary virology in CSIRO was motivated by a need to have personnel and facilities available to cope with the possible introduction of an exotic disease of livestock into Australia. It is a matter for some satisfaction that the idea of establishing a high security laboratory, put forward as early as 1961, is now well underway and should be functional by 1983. I refer of course to the Australian National Animal Health Laboratory being built at Geelong, Victoria by CSIRO.
One of the exotic arbovirus diseases of livestock that motivated much of our thinking in CSIRO was Bluetongue of sheep. The unexpected isolation of a bluetongue virus from a pool of Culicoides spp collected in the Northern Territory is now well known. Now that the initial shock of finding this agent in Australia is passed, we are left with a series of very interesting questions relating to the natural history of Bluetongue, some of which we will be considering in this symposium.
Another area of great interest to veterinarians is the dire consequences of the invasion of the foetus by arboviruses. The work on Akabane infection and its relationship to arthrogryposis and hydranencephaly of sheep and cattle will form a significant segment of our symposium. I cannot help wondering whether, in the field of human developmental abnormalities, some of these might be shown eventually to be the result of infection of the mother with an arbovirus which is the human analogue of Akabane virus, and I note that the programme carries one paper related to this topic. …………