Rates of sexually transmitted infections likely rose during the pandemic - National Geographic

Stay-at-home orders, coupled with a fear of exposure to COVID-19, seemingly kept many people confined at home and out of the arms of unknown partners throughout much of 2020. But in a counterintuitive twist, experts are warning of a probable—and alarming—increase in cases of sexually transmitted infections in the United States.

The main concern is that the pandemic hampered testing efforts for diseases such as chlamydia, gonorrhea, and syphilis during the past two years. Testing is a critical part of controlling the spread of these infections, in part because both chlamydia and gonorrhea can initially appear without any symptoms.

Between 2015 and 2019, documented cases of all three diseases had increased by 30 percent. Then, from 2019 to 2020, Centers for Disease Control and Prevention data suggested that chlamydia cases dropped by 14 percent, while cases of primary and secondary stages of syphilis experienced a modest decline of 0.9 percent. But experts now say this dip was not real, and that cases simply fell because we weren't testing.

Though 2021 case numbers for sexually transmitted diseases (STDs) are still being collected, there are worrying signs; initial reports show that gonorrhea cases have climbed, and the CDC reports that there were more cases of infants with syphilis in 2020 than in 2019.

Casey Pinto, an assistant professor of public health at Pennsylvania State University, led a May 2020 study showing that as COVID-19 case rates increased across the country, the number of tests administered for sexually transmitted infections fell dramatically. By April 2020 in New York, for example, the rate of people testing positive for COVID-19 soared to more than 25 percent, while sexually transmitted infection (STI) testing rates dropped by more than 75 percent.

"It is implausible—completely implausible—that we would have had such STI successes because of COVID-19," says Julie Dombrowski, associate professor of medicine and epidemiology at the University of Washington and deputy director of Seattle and King counties' HIV/STD programs.

Amid the crush of the pandemic, many clinics across the country also prioritized symptomatic patients. "It was very distressing to make that decision," Dombrowski says. Left untreated, sexually transmitted diseases can have dire consequences, including infertility, blindness, and death. Some untreated infections can also be a risk factor for contracting HIV, according to the CDC, because a festering sore or inflammation could absorb the virus.

And as they sort through their own data, many healthcare providers say they are seeing increases in cases of STDs. "We're seeing more positives than we normally do," says Barbara Van Der Pol, associate professor of medicine and public health at the University of Alabama at Birmingham and director of the UAB STD Diagnostics Laboratory.

The uncertainty in the numbers is especially worrying, because it can contribute to unknowing spread. Gonorrhea is asymptomatic for most women who get it. Chlamydia, which is the most frequently reported bacterial STD in the U.S., is asymptomatic for up to 50 percent of men and 80 percent of women. A burning sensation while urinating is a common symptom for both infections, but without the proper test, it can lead to a misdiagnosis of a urinary tract infection, Pinto says.

"Every missed case, every asymptomatic person, is a person who thinks they're not infected—so they're willing to take the same amount of risk that they took before," says Pinto.

The drop in positive STI tests, explained

In the earliest months of the pandemic, many clinics that routinely screen for sexually transmitted diseases shut down, and their staff were diverted to help with coronavirus testing and contact tracing. By May 2020 the National Coalition of STD Directors—a public health organization with partners in all 50 states—reported that 83 percent of STD programs in the U.S. were deferring services, and that 66 percent had experienced a decrease in testing. By August 2020 it reported one in five STD programs were "completely disrupted."

Many of Seattle and King counties' HIV/STD program workers were diverted to COVID-19 response, Dombrowski says. So, like many health departments and clinics across the country, they "immediately prioritized patients who had symptoms or who needed same-day treatment," she says. Soon after, they stopped screening any asymptomatic patients. In April 2019 the sexual health clinic saw 990 patients; a year later, it saw just 399.

Amanda Cary, a nurse practitioner and manager of the sexual health department at Whitman-Walker Health in Washington, D.C., was used to walk-in waiting rooms packed with people seeking both routine and urgent tests. But amid the pandemic, the center stopped its walk-in policy, Cary says. According to data provided by Whitman-Walker, the center experienced a cumulative 43 percent decrease in chlamydia, gonorrhea, and syphilis testing in 2020 compared to 2019.

Another challenge that the clinics faced was a shortage of tests. In a survey of STD health departments, the CDC reports that 51 percent of respondents lacked gonorrhea and chlamydia tests in April 2020. The CDC collected additional survey responses through January 2021, by which time 38 percent said they didn't have enough tests.  

COVID-19 tests use many of the same materials as STI tests, says Van Der Pol. "The swabs that we use for women to self-collect their own specimens—those are the exact same swabs that are being used for nasal testing" for COVID-19, she says.

Laboratories that run the test results were also diverted to work on COVID-19, swapping routine STI tests for the PCR and antigen tests that detect the coronavirus. Each year the UAB STD Diagnostics Laboratory runs approximately 20,000 STI tests, Van Der Pol says. But in 2020 "my laboratory doubled its volume of work—and we did zero STI testing," she says.

What experts worry about now

Today, clinics and laboratories are crawling back toward their pre-pandemic testing practices, with many—if not most—resuming routine testing and some once again welcoming walk-in patients. The clinics and laboratories included in this article each report they are operating at 70 to 80 percent of their normal capacity. (Their day-to-day rates are still anything but normal. Van Der Pol says it's still hard to get some of the most basic laboratory supplies, such as bleach and gloves.)

However, many experts worry the damage has already been done. Pinto's study found that it's likely more than 150,000 STI cases were missed through July 2020 alone.

Whitman-Walker reports that its chlamydia and gonorrhea rate sat at 11.7 percent in 2019, and by November 2021 the rate had already reached 11.2 percent—likely an underestimate with testing still hovering at 80 percent of its pre-pandemic capacity. The numbers are more dramatic for syphilis, which went from 14.2 percent in 2019 to 16.5 percent in 2020.

At the Los Angeles LGBT Center, which provides STD and HIV testing, supervising epidemiologist Nicole Cunningham says that after an initial dip in cases of each of the infections for which it tests, the center is now seeing spikes across the board. By June 2021 the center was testing as often as it had in 2019, and between June and October, cumulative gonorrhea cases increased by 23.8 percent compared to the same time period in 2019, Cunningham says.

But because of the pandemic's effects, true increases are tough to identify: Are increased numbers a catch-up of sorts—the result of running a backlog of tests that would have, under normal circumstances, been processed in 2020? Or do these increases represent true prevalence—an uptick in actual disease spread?

"It remains challenging to understand exactly what is happening with STI cases," Dombrowski says. Because cases were increasing each year before COVID-19, "presumably, some of that would have continued if it wasn't for the pandemic." But decreased testing and missed asymptomatic cases almost certainly led to some increased spread, she says, adding that many experts expect to see a major increase in sexually transmitted diseases in the coming months.

Pinto also worries that people are still deferring routine appointments out of COVID-19 concerns, or that such visits have "fallen off their radar" after months of going without them.

"This pandemic has upturned everyone's lives," she says. "I fully suspect that this is not going to be a blip. This is going to be a huge spike, and our baseline [of STI cases] will eventually be much higher."