[Arthralgia and rash from Australia caused by Ross river virus]

A 58-year-old entomologist presented with disabling arthralgia after a recent visit to the Northern Territory of Australia. A faint maculopapular rash was noticed on the trunk and limbs. The presumptive diagnosis of RRV disease was confirmed by the finding of IgM and IgG antibodies against RRV in serum. RRV, a mosquito-transmitted alpha virus, is the most common cause of arboviral disease in Australia. This disease, initially referred to as epidemic polyarthritis, is characterised by joint pain, rash and constitutional manifestations. The reservoir of RRV are marsupials, other mammals and birds, but mosquitoes may also transmit the disease between humans. The diagnosis is mainly based on RRV-specific serology. In case of arthritis viral RNA sometimes can be detected in synovium biopsies by PCR. No specific therapy is available; the prognosis is favourable. Prevention is based on protection against mosquito bites by wearing clothes to protect the skin, and by using insect repellents.