Arbovirus infection in Western Queensland: Serological studies, 1963–1969

Abstract

A serological survey of domestic fowls in south-west Queensland in 1964 showed evidence of widespread infection with Kunjin and Sindbis viruses 12 to 24 months earlier at Charleville and other centres as far west as Bedourie. At Charleville antibody was more frequent to both viruses, especially to Kunjin, in birds exposed near the Warrego River. Subsequent exposure of sentinel chickens gave evidence of infection with Sindbis virus at Charleville in early 1967, in the summer of 1967–1968 and in early 1969, but not (or equivocally) in drought years 1965 and 1966. An outbreak of epidemic polyarthritis in man at Dirranbandi in early 1966 was associated with a high level of antibody to Ross River virus in the community. Haemagglutination-inhibition titres of 640 or greater were significantly associated with recent clinical disease. Antibody to group B viruses was uncommon in western Queensland residents less than 20 years old; serological tests showed evidence of dengue infection in adults and some evidence of infection with members of the Murray Valley encephalitis-Kunjin-Alfuy subgroup in all ages. The results are discussed as showing the need to seek for evidence that Kunjin and Sindbis viruses may cause disease in western Queensland and as indicating problems in serological diagnosis of epidemic polyarthritis in communities with high prevalence of antibody to Ross River virus. The association of Kunjin virus dissemination with high rainfall in south-west Queensland is compared with observations by other workers on Murray Valley encephalitis in the Murray Valley.