Scientists found that the illness is less common in regions with high UV levels. Exposure to sunlight may inactivate viruses on the skin like the varicella-zoster virus, responsible for chickenpox and shingles, making it harder to spread.
Lead author of the study, Dr Phil Rice said, "No-one had considered UV as a factor before, but when I looked at the
epidemiological studies they showed a good correlation between global
latitude and the presence of the virus."
The study is published in the biology journal Virology.