We report a higher percentage of Sindbis virus-specific IgG in serum from patients attending a rheumatology clinic (18.8%) compared with healthy residents (9.6%) and patients with acute febrile illness (9.4%) in Free State Province, South Africa. Sindbis virus infection should be considered a potential cause of arthritis in South Africa.
Keywords: Sindbis virus; South Africa; Vector-borne infections; antibody; arthritis; mosquitoborne; serosurveillance; viruses; zoonoses.