Chlamydia Infection among Patients Receiving Treatment for Gonorrhea in Sexually Transmitted Disease Clinics in the United States

Summaries for Patients are a service provided by Annals to help patients better understand the complicated and often mystifying language of modern medicine.

Summaries for Patients are presented for informational purposes only. These summaries are not a substitute for advice from your own medical provider. If you have questions about this material, or need medical advice about your own health or situation, please contact your physician. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the American College of Physicians.

The summary below is from the full report titled "Chlamydia trachomatis among Patients Infected with and Treated for Neisseria gonorrhoeae in Sexually Transmitted Disease Clinics in the United States." It is in the 5 August 2003 issue of Annals of Internal Medicine (volume 139, pages 178-185). The authors are S.B. Lyss, M.L. Kamb, T.A. Peterman, J.S. Moran, D.R. Newman, G. Bolan, J.M. Douglas Jr., M. Iatesta, C.K. Malotte, J.M. Zenilman, J. Ehret, C. Gaydos, and W.J. Newhall, for the Project RESPECT Study Group.

What is the problem and what is known about it so far?

Sexually transmitted diseases (STDs) are infections spread from one person to another during sexual relations. Chlamydia trachomatis (chlamydia) and Neisseria gonorrhoeae (gonorrhea) are bacteria that are common causes of STDs in the United States. Both infections can cause symptoms such as discharge from the vagina or penis, pain with urination, or abdominal pain. However, many people with chlamydia or gonorrhea have no symptoms. Treatment with antibiotic drugs is important to get rid of symptoms, avoid spreading the infection to other people, and prevent complications of the infections. In women, chlamydia and gonorrhea infection can cause difficulties in becoming pregnant (infertility). Infections in pregnant women can lead to premature or low-birthweight infants and serious infections in newborns.

In the early 1980s, studies showed that nearly half of people with gonorrhea infection also had chlamydia infection. Because tests for chlamydia were available only in research settings, the Centers for Disease Control and Prevention recommended that all patients treated for gonorrhea should also get "co-treatment" for chlamydia, and this has remained the standard of care. Since the 1980s, testing for chlamydia has become more widely available. Some tests are expensive, and no accurate tests provide results that are immediately available at the time the patient is in the clinic. Testing would mean requiring the patient to wait for the results and then come back for another clinic visit after the results are available. For these reasons, many STD clinics do not routinely test for chlamydia.

Since the early 1980s, gonorrhea infection has become less common in the United States. It is unclear whether chlamydia continues to be as common a co-infection in patients treated for gonorrhea as it was when the Centers for Disease Control and Prevention first recommended that all such patients be co-treated for chlamydia.

Why did the researchers do this particular study?

To find out whether chlamydia infection continues to be common enough in patients treated for gonorrhea to justify co-treatment.

Who was studied?

3885 heterosexual patients seen in one of five STD clinics (Baltimore, Maryland; Denver, Colorado; Long Beach, California; Newark, New Jersey; and San Francisco, California) between July 1993 and October 1995. All patients were participating in a study of STD counseling and were tested for gonorrhea and chlamydia as part of that study.

How was the study done?

The researchers calculated the percentage of patients treated for gonorrhea who tested positive for chlamydia.

What did the researchers find?

Of the patients treated for gonorrhea, 19% of the men and 35% of the women tested positive for chlamydia.

What were the limitations of the study?

The results of this study may not apply to 2003, to patients treated in settings other than public STD clinics, or to patients in other geographic locations.

What are the implications of the study?

Chlamydia infection is common enough in patients receiving treatment for gonorrhea in STD clinics to justify routine treatment of chlamydia.