Alphaviruses: an emerging cause of arthritis?

PURPOSE OF REVIEW: In recent years some extensive and alarming outbreaks of disease caused by alphaviruses, including arthralgia or even severe and long-lasting arthritis have taken place. Therefore, awareness of this possibility should be increased. RECENT FINDINGS: Studies on the epidemiology of alphaviruses, especially regarding Ross River, Chikungunya and pogosta disease have been carried out. They appear to have spread into new geographic areas. The biological cycle of these viruses involves vertebrate hosts and arthropod vectors, of which mosquitoes are the most important and pass the infection to humans. It is apparent that not only changes in the climate but also increasing travel and trade, and urbanization favour the spread of both alphaviruses and of mosquitoes. Clinical studies have confirmed that arthritis, which is a part of the disease entity, may be quite severe and long lasting. The need of better control of mosquitoes and proper control measures against them is pointed out. SUMMARY: The most important alphaviruses causing joint inflammation, the clinical picture of the diseases and their epidemiological features are described. Arthritis caused by alphaviruses is certainly increasing and it should be kept in mind as a possibility especially in those cases where the disease starts with flulike symptoms, and rash is involved.