Researchers who analyzed pooled data from several studies concluded that using condoms was linked to a modest reduction in the risk of acquiring the herpes simplex virus 2 (HSV-2), although the effect was not as large as that observed with other sexually transmitted diseases.
The research was the work of lead author Emily T. Martin from the University of Washington and the Seattle Children’s Hospital, and colleagues, and is published in the 13 July issue of the Archives of Internal Medicine..
Genital herpes is a sexually transmitted infection (STI) caused by the herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2), although HSV-2 accounts for most cases. The virus can stay in the body indefinitely, but the number of outbreaks tends to lessen over the years.
Most people who have genital herpes have no or slight symptoms, but when they do occur they appear as one or more blisters near or on the genitals or rectum. The blisters rupture and cause ulcers that can take up to a month to heal the first time, and not so long the second time which usually happens weeks or months after the first outbreak.
Research on how effective using condoms might be in lessening the spread of HSV-2 is inconclusive, which is why Martin and colleagues decided to carry out a pooled analysis. They wrote that to their knowledge this was the:
“Largest analysis using prospective data to assess the effect of condom use in preventing HSV-2 acquisition.”
For the study they identified 6 prospective studies that had collected data on individual condom use and where HSV-2 had been confirmed with lab tests. Longitudinal studies are studies that observe patterns of behaviour or drug use over a length of time and link them to outcomes measured during or at the end of the period.
The study investigators were able to supply Martin and colleagues with individual-level data so they could do a pooled analysis (in effect treat the amassed data statistically as if it had come from one large study).
For the analysis they used two ways of measuring effective condom use: they worked out a percentage of total sex acts that used condoms and they also used a figure calculated from absolute numbers of unprotected sex acts.
The results showed that:
- The pooled data covered 5,384 people who did not have HSV-2 at the start of an overall total of over 2 million days of follow up.
- 415 people tested positive for HSV-2 during the follow up.
- People who used condoms 100 per cent of the time had a 30 per cent lower risk of acquiring HSV-2 than those who never used them.
- The risk of acquiring HSV-2 went up steadily and significantly with each unprotected sex act.
- These ratios were the same for men and women.
The authors concluded that:
“Although the magnitude of protection was not as large as has been observed with other STIs, we found that condoms offer moderate protection against HSV-2 acquisition in men and women.”
“A Pooled Analysis of the Effect of Condoms in Preventing HSV-2 Acquisition.”
Emily T. Martin; Elizabeth Krantz; Sami L. Gottlieb; Amalia S. Magaret; Andria Langenberg; Lawrence Stanberry; Mary Kamb; Anna Wald.
Additional sources: CDC.
Written by: Catharine Paddock, PhD