Herpes :: Genital herpes risk increases up to age 32

People aged between 26 and 32 have at least twice the risk of acquiring genital herpes compared to younger people, a new University of Otago study shows.

The Department of Preventive and Social Medicine researchers say their findings suggest that current efforts to prevent this sexually transmitted infection should not just focus on the young.

The research, from the long-running Dunedin Multidisciplinary Health and Development Study, found that among men the rate of acquiring herpes simplex virus type 2 (HSV-2) infection when aged 26 to 32 was double what it had been up to age 26. Among women, the rate remained similar.

Taking the number of sexual partners into account, the researchers found the risk was three times higher for men in the later age bracket, and for women, this doubled.

Paper co-author Dr Nigel Dickson says the study, just published in international journal Sexually Transmitted Infections, is the first in the developed world able to look at rates of herpes infection in both men and women from their teenage years to their thirties.

“What makes this study unique is that as the study members’ blood had been taken at ages 21, 26 and 32 we were able to detect when new HSV-2 infections occurred,” Dr Dickson says.

By age 32, just over one in five of the women (22.5 per cent) and one in seven of the men (14.6 per cent) in the Study, had evidence of past infection with HSV-2 – the most common virus causing genital herpes. The proportion infected rose with increasing number of sexual partners.

“The most likely reason for the risk to increase with age is that, as a person gets older, there is a tendency for their new sexual partners also to be older and hence more likely to harbour HSV-2. Also, as relationships tend to last longer as people get older, this is also likely to increase the risk of transmission,” he says.

Professor Charlotte Paul, another co-author, says while the highest rate of acquiring herpes infection was among those with 10 or more partners between 26 and 32 years, the risk was also high for those with fewer partners.

“This is also an important finding. Two-thirds of new infections in women actually occurred among those having four or fewer partners in that time, compared to less than 20 per cent for women up to age 26. A similar pattern was seen for men,” Professor Paul says.

Dr Dickson says the results are especially relevant to childbearing women.

“The late 20s and early 30s are now the most common ages for giving birth. This is when the risk of acquiring HSV-2 is higher and women with new infections are most at risk of transmitting the virus to their infants. This can have major consequences,” he says.

?The study has significant implications for public health policy. Prevention in relation to sexually-transmitted infections has tended to focus on young people. Yet, to control the spread in populations where a high prevalence of infection is driving a large number of new cases, it is important to address all factors which contribute to this at any age.

“What’s more, transmission of HIV is enhanced by HSV-2 infection, so controlling the current spread of HSV-2 is likely to reduce the spread of HIV though the population in the future.”

The study was funded by the Health Research Council of New Zealand.


Leave a Comment