In 1979, a major outbreak occurred in Fiji and spread to other Pacific islands, including Tonga and the Cook Islands. Infection is rare in prepubertal children and increases with age. In those affected, the disease can cause incapacity to work for two to three months and sometimes longer. Method of Diagnosis Serology can show a rise in antibody titre to Ross River virus. The virus may be isolated from the blood of acutely ill patients.
Tests are usually necessary to distinguish it from other causes of arthritis.
However, in the event of a local outbreak clinical diagnosis may be sufficient. Transovarian transmission in the mosquito Aedes vigilax has been demonstrated in the laboratory, making an insect reservoir a possibility. It is transmitted by mosquitoes Culex annulirostris, Ae. camptorhynchus. Ae. polynesiensis and other Aedes spp. of mosquitoes. Incubation Period Usually three to 11 days.