VIENNA – Staffers at the Centers for Disease Control and Prevention are developing and will soon start prospectively testing a new approach of universal, opt-out chlamydial infection screening for girls and women aged 15-24 years. In making this change, CDC is recognizing that current U.S. recommendations for sexually active girls and women in this age group are producing woefully low screening rates of roughly 30%, according to CDC staffers.

CDC researchers developing this new approach to Chlamydia trachomatis screening performed a cost-effectiveness analysis of this screening paradigm and found it was "very cost effective," with an estimated incremental cost of $1,372 for each quality-adjusted life year gained. In contrast, the current risk-based approach to screening for chlamydial infections among women in this age range has a cost effectiveness of about $41,000 per quality-adjusted life year gained, Dr. Karen Hoover said at the joint meeting of the International Society for Sexually Transmitted Diseases Research and the International Union Against Sexually Transmitted Infections.

According to a preliminary economic analysis by Kwame Owusu-Edusei Jr., Ph.D., of the CDC’s Division of STD Prevention in Atlanta, universal, opt-out screening may prove to have the added benefit of boosting screening rates from the current level of 30% overall among sexually active girls and women aged 15-24 and as low as 11% in sexually-active 15-year-old girls to an overall rate of 52%. The CDC’s planned changes are expected to raise the participation level to at least 75% among the sexually-active subgroup (and an expected 5% participation rate among those who are not sexually active in this age group, who would be advised not to undergo screening).

The higher screening uptake rate should, within less than 5 years, cut the prevalence of chlamydial infection in these girls and women from the current levels of 3% to nearly 1%, and in the same time frame it should also drop infection rates among men from just over 2% to below 1%, said Dr. Hoover, an ob.gyn. and medical epidemiologist in the CDC’s Division of STD Prevention.

Another benefit would be removing the stigma that the current, risk-based system generates by making many girls and women feel that they have had "bad" sex or promiscuous sex because they are now at risk of harboring chlamydial infection and need screening, Dr. Hoover said. Universal screening with opt-out would "normalize" screening in the eyes of the target population.

Routine, annual screening of sexually-active U.S. girls and women aged 24 years and younger for chlamydial infection was first recommended by the U.S. Preventive Services Task Force for about a decade, and most recently in 2007 (Ann. Int. Med. 2007;147:128-34). The CDC also recommends this screening approach for girls and women aged 25 years and younger (MMWR 2010;59(RR12):1-110).

Although the new screening model is still in development, it would likely be patient centered and hinge on having the reception staffs at primary care physicians’ offices routinely ask girls and women in the target age group to supply a urine specimen or self-administered vaginal swab at the start of all visits to any primary care provider – gynecologists, pediatricians, family practice physicians, or internal medicine physicians – along with an information sheet or pamphlet. The process would resemble the way that pregnant U.S. women are routinely asked to supply a urine specimen at the start of all their antenatal office visits. "This is very simple for clinics to implement," Dr. Hoover said at the meeting.

Routine specimen collection from all girls and women in the target group would help remove the stigma from specimen collection, Dr. Hoover said in an interview. The information patients receive would encourage them to discuss screening with their physicians, when they could exercise their opt out.

Although this approach could result in a modest amount of overtesting, the huge cost-effectiveness advantage of universal opt-out screening compared with the current, risk-based approach leaves a lot of margin to accommodate some overtesting and still be cost effective.

The only other infectious disease currently screened in the United States by a universal, opt-out system in a target age group is HIV, she noted.

Dr. Hoover said that the CDC would like to pilot universal testing in several types of U.S. clinical practice. Testing of the screening model should start within a few years, she said.

"We need a paradigm shift; we need to do this differently. As long as we continue to rely on clinicians to change their behavior [and initiate more screening than they currently do] we will never get to where we want to be" with C. trachomatis screening, she said.

Dr. Hoover had no disclosures.

mzoler@frontlinemedcom.com

On Twitter @mitchelzoler

CDC moves to cast a wider Chlamydia screening net