Birth control may boost risk of carrying staph bacteria
Taking birth control pills may make women's bodies more hospitable to staph bacteria, a new study from Germany suggests.
In the study, women taking hormonal contraception
were
about twice as likely to persistently harbor staph bacteria in their
nasal passages compared with women not taking hormonal contraception.
The findings suggest that the widespread use of birth control
increases the "pool" of people harboring the bacteria, which in turn,
may contribute to its spread to people susceptible to getting sick from
an infection, said study researcher Dennis Nurjadi, of the Institute for
Tropical Medicine in Tübingen.
The women in the study did not have staph infections. Many people carry the bacteria, called Staphylococcus aureus,
on their skin or in their nasal passages without any problems. However,
the bacteria can cause skin infections, particularly inside cuts and
scratches, and infections can be lethal if they enter the bloodstream,
according to the Mayo Clinic. People with weakened immune systems are
particularly susceptible to staph infections.
The study only found an association, and not a direct cause-effect
link between taking birth control and harboring staph. But if the
findings hold up in future studies, it would mean that about 20 percent
of women who carry the bacteria do so because they use hormonal
contraception, the researchers said.
The study was published Sept. 5 in the journal Clinical Infectious Diseases.
Nurjadi and colleagues analyzed information from 1,180 young men and
women who were seeking health advice before traveling to subtropical
regions and provided two nasal swabs at least a month apart.
About 22 percent of participants carried Staphylococcus aureus in their nasal passages on both occasions, and were considered "persistent" carriers.
Women who took hormonal contraception were 1.9 times more likely to
be persistent carriers compared with women who did not take hormonal
contraception.
Additionally, the study showed that men were more likely to carry the
bacteria than women who were not taking contraception. However, women
taking contraception were more likely to carry the bacteria than men.
The findings held after the researchers took into account factors
that could affect the likelihood of carrying the bacteria, including
age, animal contact, smoking habits and history of skin infections.
Previous studies have found women with high estrogen levels are more likely to carry Staphylococcus aureus compared
with women who have lower levels. It could be that high hormone levels
affect the immune system, and in turn, make women more prone to carrying
the bacteria, the researchers said. A study published last year found
women in Africa who used hormonal contraception were at increased risk of acquiring HIV.
