New At-Home STI Test Could Help Stop the Spread of Infection

Checking for sexually transmitted infections (STIs), which are notoriously underreported and stigmatized, may soon get easier now that U.S. authorities have recently approved the first commercial at-home test kit for STIs other than human immunodeficiency virus (HIV). The kit tests for gonorrhea and chlamydia from a vaginal swab or urine sample that can be collected in the privacy of one’s home. The samples are mailed to a lab for analysis, and people with positive results are put in contact with a physician. Experts say that the Food and Drug Administration approval this past November could lead to far more STI testing in the U.S., but questions remain about how officials will handle the approval of other, similar tests in the future.

The FDA’s approval of the kit, called Simple 2 and made by a company called LetsGetChecked, comes as STI cases in the U.S. are rising at a rate unprecedented in the modern era. Gonorrhea cases rose by 28 percent between 2017 and 2021, and chlamydia cases rose by 4 percent between 2020 and 2021—a trend some epidemiologists attribute to decreased funding for public health services during this period.

Although the nation’s STI epidemic is getting worse based on the STI test results that do get reported, the overall testing rates themselves remain low. This is largely because many people fear buying a test at a drugstore or going into a primary care facility—where experts say clinicians can sometimes appear judgmental about unprotected sex, says epidemiologist Barbara Van Der Pol at the University of Alabama at Birmingham. Being able to order a reliable kit online without a face-to-face interaction or doctor’s prescription could help normalize STI testing, she says. “Instead of avoiding it, it will help people catch things earlier,” she says, adding that the approval is “a great thing.”

LetsGetChecked is not the first to offer mail-order or over-the-counter self-collection tests. Numerous companies offer similar services that can cost hundreds of dollars and are not always covered by insurance. But Van Der Pol says FDA approval for Simple 2 makes it more likely that government and private insurers will eventually cover the test, which currently costs $99. Approval could also make it possible for local public health agencies to offer the kits at health fairs or free clinics, rather than expecting people to seek STI exams or kits out on their own.

“It’s a game changer,” says Charlotte Gaydos, an infectious disease expert at Johns Hopkins University. For nearly 20 years her team has offered a free testing program, called I Want the Kit, for STIs including HIV. The team sends people vaginal, penile or anal swabs with instructions to collect samples and mail the swab back to Johns Hopkins for analysis. Research from Gaydos’s lab and others has shown that people can safely perform self-collection at home and obtain accurate results. In a statement to Scientific American, the FDA said it evaluates the stability of mailed samples and whether users can correctly collect them, as well as whether kits contain hazardous chemicals that could potentially harm users.

Gaydos’ team analyzes I Want the Kit samples using FDA-approved assays similar to those used in Simple 2, and she says her group plans to seek direct approval for its collection kits as well. Test kits such as those used for COVID, along with genetic tests such as AncestryDNA, have already normalized at-home testing, she says. This could increase the number of people regularly testing themselves for STIs, Gaydos adds. “Things are very much changing for the better.”

The FDA’s recent approval comes with a shift in how the agency regulates tests for STIs and other conditions. Many clinics use assays that are categorized as so-called lab-developed tests (LDTs), which do not currently require FDA approval. Some LDTs allow people to collect their own sample, although the collection and testing must both be done in a clinic, not at home.

But the FDA still considers at-home collection kits to be devices that are subject to regulation and don’t fall within the LDT category—meaning some commercial STI-testing companies may have been operating in an unclear legal space. The FDA has generally not enforced this regulation. But in September the agency announced a proposed rule that would require the makers of both LDTs and over-the-counter at-home tests (including STI tests already on the market) to seek FDA approval.

Those plans have drawn pushback from some public health groups, particularly those working with high-risk LGBTQ populations, who worry it will cause companies to roll back or stop investing in STI tests already available on the market. In a public comment, the National Alliance of State & Territorial AIDS Directors (NASTAD) wrote that requiring companies and health departments to go through the lengthy and expensive FDA approval process would undermine public health efforts by “delaying identification of infection, engagement in treatment, undercutting public health surveillance, and, most crucially, exacerbating health inequities.”

The FDA says it exercises enforcement discretion on such tests. When deciding whether to crack down, an agency spokesperson explained to Scientific American, it “considers a number of factors, and may consider whether the laboratory is actively working with the FDA to achieve authorization.”

Ultimately, Gaydos says, public health experts would like to see FDA approval for truly at-home STI tests that provide an immediate result without the need to mail samples to a lab—much like how COVID test results appear minutes after sampling. Two companies already have FDA approval for immediate tests for chlamydia and gonorrhea, but the analysis systems are so complex and expensive that the tests can only be performed in a clinic. Gaydos says STI test kits that can be used in a similar way to at-home COVID tests are already undergoing clinical trials, and the results so far show them to be highly accurate. “We’re very close,” she says.

A main concern with at-home tests is that public health agencies such as the U.S. Centers for Disease Control and Prevention would lose the ability to easily track STI rates. As seen with COVID home testing, people rarely voluntarily report at-home test results. Some states require companies and clinics that analyze samples to report positive results to public health authorities, but it would be difficult to enforce this with individuals. LetsGetChecked did not immediately respond to questions about whether it plans to report positive results obtained from its self-collection kits.

But Van Der Pol says these are minor concerns, given the urgent need for increased STI testing. Because care cannot be fully monitored, many STI statistics are already based on voluntary self-reports. It is impossible to confirm, for example, whether people with such infections take antibiotics they may have been prescribed or whether they inform their partners. Furthermore, epidemiologists estimate that only a small percent of STI cases are detected in the first place because the majority of cases of some STIs, such as chlamydia, are asymptomatic and so few people seek testing in clinics.

“We can’t be paralyzed by the need for perfection, and [LetsGetChecked’s service] is still one more option in our tool kit,” Van Der Pol says. If even half a million people tested themselves with Simple 2 and 20 percent of those sought care in the clinic, she says, “we still treated 100,000 more cases than we knew about.”