Self-reported morbidity of Barmah Forest virus infection on the north coast of New South Wales

Objective: To describe the clinical features and disability associated with Barmah Forest virus (BFV) infection. Design: Retrospective postal survey. Setting: North Coast Public Health Unit, Lismore, New South Wales, January to October 1995. Subjects: All 84 subjects notified by mandatory laboratory reporting as positive for BFV IgM by enzyme-linked immunosorbent assay. Outcome measures: Demographic information, self-reported symptoms, disability and treatment. Results: Response rate was 77%. Peak incidence was in the 30-50 years age group, with almost identical numbers of men and women affected. The most common symptoms were lethargy (89%), joint pain (82%) and rash (68%). These were also generally the first symptoms to appear. Thirty of 54 respondents (56%) reported time off work and 27 of 53 (51%) reported illness lasting more than six months. Those who had a rash were significantly more likely to have recovered by the time of the survey than those who had no rash (odds ratio, 10.3; 95% confidence interval, 1.8-76.6). No treatment led to more than slight relief of symptoms. Conclusion: Symptoms of BFV infection appear similar to those of the better-known Ross River virus infection, and clinicians should consider both in patients with symptoms of arboviral disease. The wide distribution and long duration of illness make BFV a potentially significant cause of morbidity in Australia. A possible association between the presence of a rash and improved prognosis needs further investigation.