Two-thirds of adults under 50 have herpes

TWO-THIRdS of adults under 50 are infected with herpes, the virus that causes cold sores, research shows.

Experts are particularly concerned that in Britain and other Western countries, growing numbers of youngsters are being infected when they become sexually active.

World Health Organisation research has found that 4.1billion women and men around the world are infected, calling it an ‘enormous burden’.

Herpes can cause pregnancy complications and increase the risk that a carrier will get HIV.

There are two strains of the virus, which is usually harmless – HSV-1, which causes cold sores, and HSV-2, which leads to genital herpes.

Once someone is infected it remains in their body for life. It is usually dormant, but occasionally the virus becomes active and triggers painful cold sores or genital warts.

The HSV-2 virus is particularly dangerous for pregnant women because it can trigger a miscarriage, or be passed on to the foetus. WHO researchers used population statistics and previously published studies on herpes rates to estimate the numbers of adults infected.

They calculated that 3.7billion of those under 50 have the type of herpes that causes cold sores, while another 414million suffer from genital herpes.

There are no figures for the UK alone, but other research suggests that at least 70 per cent have herpes.

The research, published in the journal PLOS ONE, concludes: ‘These WHO estimates show an enormous burden of herpes globally.’

They have urged drugs firms to develop a jab, but although medical trials are under way it is not likely to be available for at least five years.

WHO medical officer Sami Gottlieb said: ‘We really need to accelerate the development of vaccines.’