The number of sexually transmitted infections (STDs), such as syphilis, has been on the rise in the US in recent years. But why are STD rates rising now and what can be done to reverse that trend?
Decreased public health focus on sexual health has been a big factor in rising STI rates, experts told Live Science.
“Increasing opioid use, COVID-19 and the mpox outbreak have exacerbated a lack of funding and resources in sexual health care, creating a perfect storm that has seen an increase in cases in recent years,” Casey Pinto (opens in new tab)an associate professor of public health sciences at the PennState Cancer Institute, told Live Science.
Changes in sexual behavior, such as a decrease in condom use and an increase in risky sexual behavior due to opioid use, also likely play a role, experts told Live Science.
Related: New ‘Worrying’ Strain of Drug-Resistant Gonorrhea Found in US for First Time
Why are STD rates rising?
The US Centers for Disease Control and Prevention (opens in new tab) (CDC) tracks the national rate of gonorrhea, chlamydia, and syphilis infections. Rates of these bacterial STIs had already been rising in the six years leading up to the pandemic. During this period, gonorrhea rates increased by an average of about 10% per year, chlamydia rates by an average of 3.6% per year, and syphilis rates by an average of 14% per year.
In 2021, during the pandemic, gonorrhea and chlamydia rates continued to rise, up about 2.5% compared to 2020, according to the latest CDC data. Both diseases can make sex painful and lead to infertility, while gonorrhea can also lead to yellow-green discharge from the genitals.
The number of syphilis cases rose more sharply during the same period, reaching the highest rate in three decades – a 27% increase compared to 2020. Syphilis can cause genital sores and rashes on the hands and feet.
Rising syphilis infections are of particular concern because they are tied to it rising rates of congenital syphilis, where the bacteria cross the placenta during pregnancy and may cause bone deformities, nerve problems, and, in some cases, miscarriage, stillbirth, or death of the newborn. According to CDC data, the number of infections with congenital syphilis has approximately tripled between 2017 and 2021.
“In the early 2000s, here in the U.S., we were on the verge of eradicating syphilis, so it’s kind of terrifying to see how much syphilis is coming back, ripping and roaring through our communities,” Dr. Joseph Cherabi (opens in new tab)an assistant professor of medicine and medical director of the St. Louis County Sexual Health clinic, told Live Science.
The real picture may be even worse, as “cases were under-reported,” especially amid pandemic-related disruptions that caused widespread closures of sexual health clinics and diverted staff from tracking STIs to monitoring COVID-19, said Cherabi. These disruptions, along with those caused by last year’s mpox outbreak, likely increased STD rates because more people had sex while unknowingly infected, Cherabie said.
One factor that many scientists believe is behind the rise in STIs is the growing opioid epidemic. Use of opioids, including prescription pain relievers and illicit drugs such as heroin and fentanyl, reached new heights during the pandemic (opens in new tab) and has been linked to risky sexual behaviors that increase the risk of STI spread, such as not using a condom and having many sexual partners, Cherabie said.
also the high level of opioid use (opens in new tab) seen in American Indian and Alaska Native (AI/AN) communities may help explain their rising HIV rates in recent years, Cherabie said.
After falling for some time, the number of new HIV diagnoses among AI/AN people started to rise again between 2018 and 2021, CDC data (opens in new tab) to suggest. This could theoretically be linked to opioid use, because sharing needles can increase the risk of HIV, which also spreads through sexual contact, Cherabie said. In addition, drugs that dramatically reduce the likelihood of contracting HIV, called pre-exposure prophylaxis (PrEP), are less readily available in these communities, compared to groups whose HIV rates are declining, he said.
Another cause of rising STI rates is the declining use of condoms, Dr. Jodie Dionne (opens in new tab)an assistant professor of infectious diseases at the University of Alabama at Birmingham told Live Science.
“Several studies show a fairly consistent decline in condom use,” which creates a physical barrier to STI transmission, Dionne said. A study that examined condom use among more than 29,000 female U.S. residents between the ages of 15 and 44 found that 3% fewer people reported using a condom during their last vaginal sex (opens in new tab) between 2017 and 2019, compared to figures reported ten years earlier.
Condoms are especially falling out of favor with those using PrEP, Cherabie added. A recent study found that between 2012 and 2017 the number of condomless sex has increased (opens in new tab) among men who have sex with men, and other research suggests that this change in behavior may be related in part to increased use of PrEP (opens in new tab)which protects against HIV, but not against other STDs.
“We need to make sure these people are aware that they can get other STDs in addition to HIV, and that they should get tested every three to six months if they have new sexual partners,” Cherabie said.
How can the number of STIs be reduced?
What measures can reverse this trend?
One strategy is to do more STD testing. Strengthening efforts to screen for STIs and congenital syphilis, through increased funding, could help reverse the rise in infections, Cherabie said. Sexual health care has been underfunded for decades, he said.
A “great opportunity” to boost testing is through home testing kits, Dionne said. “One helpful thing we learned during the COVID-19 pandemic is how easy it is for people to self-test at home when high-quality test kits are available. We can and should expand this self-testing capacity with out-of-clinic self-testing for chlamydia and gonorrhea, said Dionne. Self-testing for syphilis can be trickier because it requires a blood test, she noted.
Ongoing trials are exploring the feasibility of government-funded test kits for chlamydia, gonorrhea and HIV, which can cost about $80 to $300 each. “In trials in Jefferson County, Alabama, we’ve seen that many people who order free STI self-test kits have rarely, if ever, been screened for STIs,” Dionne said. Home tests could be a worthwhile investment if they reach historically stigmatized groups who are disproportionately at risk for STIs, she said.
Using less stigmatizing language to inform vulnerable groups about STDs could also encourage people to get tested, which could drive back infection rates, Cherabie said. Whether that will actually affect the results is unclear, though — researchers have a “very limited understanding” of whether changing levels of stigma contributed to the recent rise in STIs, Dionne said.
Scientists initially wondered whether the number of STIs is increasing due to emerging antibiotic resistance in pathogens. But so far that doesn’t seem to be the case, Dionne said. Nevertheless, antimicrobial-resistant strains are “something we want to keep an eye on because with increasing antimicrobial resistance, we’re less likely to get rid of the infection,” Cherabie said.
As the burden of STDs grows, the CDC announced funding for a new STI research consortium (opens in new tab) aimed at reversing current trends by February 27, 2023. This could be a first step in slowing or reversing the rise in STIs.