The effects of ultraviolet light irradiation on viral infections.

Exposure to ultraviolet radiation is associated with the development of cutaneous carcinomas, and with suppression of immune responses to a variety of antigens, including those of fungal, bacterial and parasitic origin, and contact sensitizers. UV irradiation also influences viral infections. It can affect viral mutation, the photolocalization of viral exanthems, viral oncogenesis, activation of viral genomes, and the suppression of immune responses to viruses. The evidence for, and mechanisms involved in, each of these categories is presented, and the effect of UV radiation on the virus-host interaction, particularly during persistent infections, is discussed.