More Women Are Walking Around With Undiagnosed Chlamydia

When the US and Canada eased up on their cervical cancer screening guidelines back in 2012—nixing the annual Pap-smear recommendation and instead suggesting women get them every three years (plus recommending against screenings for women under 21)—the goal was to reduce any unintended harms those screenings could have on young women while still maintaining effectiveness.

Now, it seems those annual Paps served a purpose outside of screening for cervical cancer: detecting chlamydia.

The news comes from a Canada-based study published in the Annals of Family Medicine, which found that fewer Pap screenings also meant fewer diagnoses of chlamydia. In the two years following the change in guidelines—between 2012 and 2014—researchers looking at Ontario medical records found that chlamydia screenings dropped 26 percent for women ages 15 to 19, and 18 percent for those between 20 and 24. The decrease in screenings led to 17 percent fewer diagnosed cases of the infection in the younger group and 14 percent fewer diagnoses in the older group.

Fewer diagnoses doesn't initially sound like a bad thing, but it is. Chlamydia, which is the most common STI in the US and worldwide, with more than 1.5 million cases reported to the Centers for Disease Control and Prevention in 2015, often doesn't have symptoms. But, left untreated, it can result in pelvic inflammatory disease, causing damage to a woman's reproductive system and even infertility.

"It's not that the actual incidence has gone down, it's just you're not identifying them," Michelle Naimer, MD, study co-author and family physician at Mount Sinai Hospital, said in an interview with STAT News. "And the risk of that is that down the road, it will just spread more and you will have more cases in the future."

Currently, the CDC recommends sexually active women under 25 get tested for chlamydia each year—which is three times more frequent than the recent recommendations for Pap smears. According to Naimer, there's an easy fix for this: Urine testing, which is as sensitive and accurate as swab testing, sans a pelvic exam. Getting physicians to remember to offer the new type of test is another story, Naimer said, though electronic medical systems and simply leaving urine collection containers in waiting rooms could help.

So, in the ever-wise words of Nicki Minaj: Guess you needed a Pap. Or, rather, yearly screenings for chlamydia if you're a woman who has sex, regardless of your Pap schedule.

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