LOS ANGELES — Condom use does matter in human papillomavirus infections, because it is associated with a shorter persistence of infection in females, according to a study of 57 sexually active female adolescents.
The study, which followed the adolescents for an average 2.2 years and included periods during which the subjects collected vaginal swabs weekly, found that in those who reported the least-frequent condom use, the mean duration of an HPV infection was 251 days, compared with a mean duration of 138 days for those reporting the most, Marcia L. Shew, M.D., said at the annual meeting of the Society for Adolescent Medicine.
Noting that a recent National Institutes of Health report concluded that previous studies have not provided good enough evidence to know whether condom use prevents or influences HPV infection and transmission, Dr. Shew said, “We were so excited when we found out that condoms had a role, and it makes sense because condom use has clearly been shown to be associated with more frequent regression in cervical intraepithelial neoplasia.”
The study, which, in addition to the weekly vaginal swabs collected by the subjects themselves, looked at cervical swabs collected by the investigators every 3 months, found that 49 of the 57 subjects got at least one infection during the average 2.2 years, for a cumulative incidence of 86%, according to Dr. Shew of Indiana University, Indianapolis.
Among them, there were 241 individual infections, or an average of about 5 per individual.
Of those infections, 168 were of a high-risk, oncogenic type of papillomavirus, and 73 were of a low-risk type. The types most frequently detected were 52 and 16, both high-risk types, and 66, a low-risk type.
Factors the study found to be associated with longer duration of infection included oncogenic type, coinfection with chlamydia, a greater number of sexual partners, and less condom use.
Analysis indicated that the mean duration of infection with an oncogenic type papillomavirus was 226 days vs. a mean 159 days for the infections with nononcogenic types.
Mean duration of infection in those cases that occurred with a concurrent chlamydia infection was 333 days vs. 96 days.
And the average duration of an infection in an individual with multiple sexual partners was 436 days, vs. 96 days in those individuals who had only one or no partners during the infection.
Some of the possibilities that might explain why condom use results in shorter infections include that someone who is having repeated sex with an infected individual might be exposed to a higher viral load, or even that semen is proinflammatory, and that somehow contributes, Dr. Shew said.
“We feel these findings have substantial clinical and public health significance, and clearly may help to reduce viral transmission,” she added.