STUDIES OF ARTHROPOD‐BORNE VIRUS INFECTIONS IN QUEENSLAND

Abstract

Summary The group‐reactive haemagglutination‐inhibition (HI) test applied to sera collected from children and sentinel fowls detected a series of infections with group B arboviruses in the Carpentaria‐Cape York Peninsula area between 1957 and 1961. The more specific neutralization test suggested that the infecting viruses included kunjin (several centres in 1958–1959), Kokobera (Mapoon, 1957–1959) and Murray Valley encephalitis (MVE) (Mitchell River, 1960), Neutralization tests of egg‐yolks confirmed the occurrence of group B arbovirus infection at several centres in north and north‐west Queensland in 1959–60 and 1960–61. Mitchell River had evidence of a very high incidence of group B infection, in that 177 of 204 human survey sera were positive to MVE by the HI test. Neutralization tests on these sera provided additional evidence that Kunjin and Kokobera can infect man. Group B antibody was less frequent in human sera collected on the east coast of Queensland. Evidence of Kokobera and possibly Kunjin infection was found in man at Lockhart River. Some sera collected in Brisbane from patients with various diagnoses and human survey sera from Murray, Yama and Yorke Islands in Torres Strait had group B antibodies suggesting previous infection with dengue. Group B antibody was found in sera from horses (central and north Queensland), cattle (north and western Queensland), kangaroos (western Queensland), wallabies (south‐east Queensland) and domestic fowls (north Queensland). Neutralization tests suggested that the kangaroo antibody was to Kokobera and the wallaby antibody to Edge Hill. MVE and Kokobera appeared to be responsible for antibody in horses and cattle, and MVE (at Normanton and Townsville) and Kunjin (at Dunbar) for antibody in domestic fowls.