Despite continuing declines in reported cases of sexually transmitted diseases in Baltimore, the city Health Department is making a push to identify people who are infected but don't know it.
Dr. Peter L. Beilenson, the city health commissioner, said yesterday that he is urging doctors and health clinics to routinely screen teen-agers and young adults for gonorrhea and chlamydia using a simple new urine test.
His comments came as researchers, reporting yesterday in the Journal of the American Medical Association, said that one in 12 young adults in Baltimore has an undiagnosed case of either chlamydia or gonorrhea.
Specifically, 5.3 percent of those tested had untreated chlamydia, while 3 percent had gonorrhea.
The findings indicate that the number of cases of the diseases in Baltimore could be about twice what is annually reported.
Doctors typically diagnose cases among people who seek medical attention for symptoms. In contrast, the screening test can identify infections among people who have no symptoms.
In the mid-1990s, Baltimore had the nation's highest rates of three sexually transmitted diseases - syphilis, gonorrhea and chlamydia - but has made strides in combating the problem.
Yesterday, Beilenson reported that the gonorrhea rate dropped about 12 percent between 2000 and 2001. The chlamydia rate has stayed about the same; new syphilis statistics are not yet available.
Though federal health authorities have not yet released comparative rates from other cities, Beilenson said he expected that Baltimore will have dropped out of the top five for all three diseases once the 2001 figures are out.
In 2000, the city ranked fourth in chlamydia and third in both gonorrhea and syphilis. Syphilis cases dropped by nearly two-thirds from its 1997 high of 669 cases to 218 cases in 2000.
Dr. Jonathan Zenilman, an associate professor of medicine at the Bloomberg School of Public Health at the Johns Hopkins University and an author of the JAMA study, said there is no reason to think that the problem of undiagnosed gonorrhea and chlamydia is unique to Baltimore.
"I don't believe these findings would be different in other places," Zenilman said, adding that a study done among men and women in the military found much the same problem.
Researchers conducting the study collected urine samples from 579 people between the ages of 18 and 35 who were selected at random. The samples were then analyzed in a laboratory, using new technology that searches for genetic evidence of the two bacteria.
Chlamydia and gonorrhea can cause pelvic inflammatory disease, ectopic pregnancies and infertility in women if left untreated.
"It is absolutely crucial that we get these tests," said Beilenson.
The Health Department has sent letters to more than 1,000 doctors and clinics, urging them to screen all sexually active patients who are under age 30 for gonorrhea and chlamydia, regardless of symptoms.
Beilenson said the urine tests can be done during routine physicals, school-based exams and other types of medical visits. "The message is that people are more at risk than they think they are, and that screening is much more convenient with these noninvasive tests," said Dr. Emily Erbelding, clinical director of the city's sexually transmitted disease program.