September 10, 1998
Nearly one in 10 female new recruits in the Army is infected with Chlamydia trachomatis, according to a study reported in today's New England Journal of Medicine. Left untreated, this Chlamydia infection causes a sexually transmitted disease (STD) that often ends in infertility. Along with a recently reported study from Hopkins on prevalence of infection in teenage girls, the new research suggests Chlamydia is a major threat to the reproductive health of young U.S. women.
The current report from a multi-institutional team led by Hopkins epidemiologists, is a wake-up call, says team leader Charlotte Gaydos, Dr. P.H., because, unlike earlier studies, this one involves adults as well as teens and multiracial populations from varied areas across the country.
Throughout 1996 and 1997, the researchers targeted new female recruits at the Army's induction center at Fort Jackson, S.C., where most of the women come for training. More than 13,204 women volunteered to participate in screening shortly after their arrival. Each filled out a questionnaire on demographics and sexual behavior. Researchers analyzed the recruits' urine samples for Chlamydia DNA using the ligase chain reaction test, a new, highly sensitive way of detecting small amounts of genetic material. They also checked the questionnaires to determine risk factors for getting the infection.
Results of the screening showed that overall, 9.2 percent of the women had Chlamydia, but that figure jumped to more than 12 percent if researchers looked only at 17-year-olds. The risk of having the disease, then, was highest for the youngest recruits. Other factors tied to disease risk were being African-American, being sexually active, not using condoms regularly or having a history of sexually transmitted disease.
"We were surprised," says Gaydos, "at the strength of some of the geographic differences." Georgia, South Carolina, Alabama, Louisiana and Mississippi had a 15 percent prevalence. "That's dramatically different from states like Oregon and Washington, which once had that high rate, but brought it down to less than 5 percent through screening and treatment," says Gaydos.
The study also points out a need for screening in men, Gaydos adds, to stop both new disease and reinfection in treated soldiers. Men are less likely to have untreated disease, she says, because they tend to have symptoms that lead them to a doctor. Somewhere between half and three-quarters of infected men experience a discharge and painful or difficult urination. "We hope this will bring routine screening of both men and women in the Army," says Gaydos.
Funding for the study came from the Department of the Army.
Other researchers are M. Rene Howell and Barbara Pare, of Johns Hopkins; Thomas C. Quinn, M.D., of Hopkins and NIH; Kathryn Clark, M.D., and Joel Gaydos of The Henry M. Jackson Foundation, Rockville, Md.; Dorothy Ellis and Rose Marie Hendrix of the U.S. Army Medical Department Activity, Fort Jackson, S.C; and Kelly McKee Jr, M.D., of the Womack Army Medical Center, Fort Bragg, N.C.