Consistent and correct condom use provides
a high level of protection against bacterial sexually transmitted infections
(STIs), US investigators report in Sexually
Transmitted Infections. Individuals who always used condoms correctly were
almost 60% less likely to be diagnosed with an infection. Consistent condom use
on its own did not reduce the risk of bacterial STIs.
“Efforts to promote condom use should be
augmented with efforts to promote their correct use,” write the authors.
“Condom use errors and problems are a global issue. Incomplete use of condoms
is a problem requiring targeted education. Rectifying issues such as poor fit
and feel of condoms and using oil-based lubricants may substantially reduce
slippage and breakage.”
Condoms are a cornerstone of HIV prevention
and sexual health campaigns.
A number of well-designed studies have
shown their protective effect against male-to-female transmission of herpes,
chlamydia, gonorrhoea, syphilis and human papillomavirus (HPV).
However, whether condoms provide protection
against the acquisition of STIs remains controversial.
Research looking at this question has had
number of important limitations. The most important of these is a failure to
adjust for incorrect use of condoms (not using condoms from the start to the
finish of penetrative sex) or condom 'accidents' such as slippage and
“Failure to control for condom breakage and
slippage may produce the analytical equivalent of condom non-use,” observe the
investigators. “A prospective study of clinic attendees found 13% incidence of
chlamydia and gonorrhoea among people reporting consistent condom use but also
reporting at least one problem with incorrect use. In contrast, among those
reporting consistency and lack of problems…no incident infections were found.”
Previous research has also relied on study participants accurately remembering whether they used condoms and if they
Investigators in the US therefore designed
a prospective study involving attendees at five sexual health clinics. Participants
received daily prompts to electronically recall incidents of penile-vaginal sex
and use of condoms.
The investigators wanted to see if
consistent condom use was protective against three common bacterial STIs:
chlamydia, gonorrhoea and trichomonas. They also wished to determine the
protective effect associated with consistent and correct use of condoms.
A total of 929 people were recruited to
the study. A urine sample was taken at the start of the study to screen for STIs
and further samples were submitted for testing after three and six months of
Most of the study participants were women (55%) and
African American (65%). Their mean age was 29 years and the mean number of
reported lifetime sexual partners was 30.
Participants reported a total of 14,970
penile-vaginal sex events, 64% of which involved the use of a condom.
Approximately a quarter of sex events (24%) with a condom involved an error or
A total of 118 STIs were diagnosed during
Incidence of STIs was 8.46% among those
reporting less than consistent condom use. This compared to an incidence of
6.71% in people who reported using condoms all the time. This difference was
not statistically significant.
The incidence of infections among people
who reported less than consistent use of condoms and incorrect use of condoms
or problems with slippage or breakage was 8.75%. The incidence among
individuals who reported consistent and correct condom use was significantly
lower at 3.35% (p = 0.023).
“Participants who used condoms both
correctly and consistently were estimated to have 59% smaller odds of acquiring
an STI over 3 months compared to participants who did not use condoms both
correctly and consistently,” note the authors. “Magnified over an entire
population, this level of risk reduction for sexually active people is
They believe that their findings probably
underestimate the protective effect of condom use against bacterial STIs: “The
six incident cases observed for people using condoms consistently and correctly
may be a result of an unprotected sex event, breakage event, etc that was not
reported….tendencies to forget, fabricate, exaggerate and under-report are