Sex infection risk 'increases in summer'

The long sunny days of summer may increase the risk of catching a common sexually transmitted infection.

Researchers using data from the Netherlands found that detection of papilloma virus infection during routine cancer screening peaks during August, because, they believe, sunlight suppresses women’s immune system defences.

Experts have long suspected that sunlight has powerful – and perhaps conflicting – effects on the body’s tendency to develop a variety of diseases, including cancer. The best example is the risk of too much sun triggering skin cancer.

However, many suspect sunshine can have less obvious influences, and can even affect susceptibility to a variety of everyday viruses like papilloma.

These viruses are spread through sexual contact, and they are the most common cause of cervical cancer. Although the virus can cause genital warts, most infected people have no outward symptoms.

“The sun is a kind of drug, a drug that influences whether a papilloma infection takes hold or not,” said Dr William Hrushesky, an authority on how disease patterns fluctuate over time.

Hrushesky, based at the WJB Dorn Veterans Administration Medical Centre in Columbia, South Carolina, presented his findings at a meeting in Orlando of the American Association for Cancer Research.

He looked at the results of more than 900,000 smear tests done in southern Holland between 1983 and 1998. The test does not detect papilloma virus directly, but it reveals abnormal cells that are typically caused by the infection.

Hrushesky found that the sunnier the year and the sunnier the month, the higher the rate of human papilloma virus.