Doctors are advising football fans who went to the World Cup in South Africa to check their HIV status if they had unprotected sex on their trip.
Up to 25,000 England fans recently returned from South Africa, where about six million people have HIV.
More than two-thirds of heterosexual men and a quarter of women who contract HIV do so through holiday sex.
An awareness campaign is urging those who may have put themselves at risk to visit their local sexual health clinic.
The campaign - 'Beer Goggle Johnny's Guide to Sexual Health' - has been launched by Birmingham's Heartlands Hospital, but is backed by national organisations.
Dr Steve Taylor, sexual health and HIV consultant at Heartlands Hospital, said nearly one in five young adults living in South Africa were infected with the virus, and in some areas it could be as high as one in three.
"During the festivities if holiday makers had unprotected sex it is more important than ever to get themselves checked out on their return," he said.
"Although the public are more aware of the dangers of unsafe sex these days, we are not seeing people putting this into practice, which is worrying.
"It's while on holiday, as people relax, soak in the sun and consume alcohol, the chance of having unprotected sex is increased.
"We want holiday makers to take precautions, pack condoms in their suitcase and attend sexual health screenings on their return if they are unsure."
He added: "The only way we can help prevent widespread infection of STIs (sexually transmitted infections) in this country is through early testing, and treating infections before they can spread - and when they are easier to treat.
"Even HIV, for so long a virus to dread, can be managed very effectively if detected in its early stages."
Source : bbc.co.uk
