Recently, the U.S. Preventive Services Task Force (USPSTF) updated its recommendations for gonorrhea and chlamydia screening based on a systematic review of the studies published since the previous recommendations in 2005/2007. The USPSTF recommended screening for chlamydia and gonorrhea in sexually active females aged 24 years or younger and in older women who are at increased risk. As far as men, the USPSTF report concluded that “the current evidence is insufficient to assess the balance of benefits and harms of screening for chlamydia and gonorrhea in men.”
The document also included a review of the diagnostic accuracy of screening tests.
In 10 new studies of asymptomatic patients, nucleic acid amplification tests demonstrated sensitivity of 86% or greater and specificity of 97% or greater for diagnosing gonorrhea and chlamydia, regardless of specimen type or test. The USPSTF now considers these tests accurate for diagnosing both sexually transmitted infections (STIs) in asymptomatic persons.
In the case of gonorrhea tests for women, the panel found that sensitivities ranged from 78.6% to 100% depending on the type of test. Reported sensitivities for male gonorrhea tests ranged from 90% to 100%. Sensitivities for chlamydia tests in women varied across platforms and specimen types from 72% to 98.2%. The four studies the panel analyzed involving chlamydia tests in men reported sensitivities ranging from 86.1% to 100%.
Gonorrhea and chlamydia are the two most commonly reported STIs in the United States. The true incidence of these STIs is difficult to estimate because most go undetected. Studies did show that infection rates were higher in women, but in recent years there has been a rise in infection rates in men. In 2012, men who have sex with men who were tested in STD Surveillance Network clinics were found to have median prevalence rates of 16.4% for gonorrhea and 12.0% for chlamydia.
USPSTF findings also reported on risk factors. Age was the highest predictor of infection rate, with people 15-24 years of age reported to have the highest rates of gonorrhea and chlamydia. Hispanics and blacks generally were reported as having higher infection rates compared with whites. Anyone who has multiple sex partners and those who do not use latex condoms were also considered at greater risk.
More details on the USPSTF review can be found at the Annals of Internal Medicine.