The number of bacterial sexually transmitted infection (STI) diagnoses has hit a record high in the United States, The New York Times reports. In 2015, there were 1,526,658 reports of chlamydia diagnoses; 395,216 reports of gonorrhea; and 23,872 reports of syphilis.

According to a new report from the Centers for Disease Control and Prevention (CDC), between 2014 and 2015, reported syphilis cases jumped 19 percent, gonorrhea cases rose 12.8 percent and chlamydia increased 5.9 percent.

The majority of the rise in gonorrhea and syphilis was among men who have sex with men (MSM). Among men, out of the 2015 diagnoses of syphilis for which the gender of the sex partner was known, 82 percent were among MSM.

Nearly two thirds of the chlamydia cases and half of the gonorrhea cases in 2015 were among 15- to 24-year-olds.

Centers for Disease Control and Prevention/2015 STD Surveillance Report

Between 2014 and 2015, the syphilis diagnosis rate among women increased more than 27 percent. However, less than 10 percent of syphilis diagnoses are among women. The rate of babies born with syphilis they contracted from their mothers increased 6 percent in one year.

The CDC’s new figures represent only actual reported diagnoses of gonorrhea, chlamydia and syphilis. The CDC estimates that each year there are more than 20 million new STIs in the United States. The total annual health care cost associated with STIs is an estimated $16 billion.

STIs can facilitate the transmission of HIV.

The CDC points to budget cuts in state and local STI programs as a possible contributor to the recent rise in diagnoses, as well as the use of dating and hookup apps.

According to Jonathan Mermin, MD, MPH, director of the CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, "It is doubtful that the STD increases reported in the 2015 STD surveillance report are attributable to the use of PrEP. While CDC estimates more than 1.2 million people who are at high risk for HIV infection would benefit from using PrEP, the magnitude of individuals currently on PrEP is not large enough to account for all of the STD increases in 2015."

STDs, or sexually transmitted diseases, is another term for STIs.

As of late 2015, an estimated 80,000 Americans had filled at least one PrEP prescription. Judging from the rapid rate of increase of the quarterly rate of new PrEP prescriptions, that figure is by now almost certainly much greater. But of course the CDC’s recent report on STIs only concerned data through 2015.

“CDC recommends that individuals on PrEP continue to use condoms to reduce the risk of STD infections,” Mermin says. “CDC also recommends that everyone on PrEP be tested for STDs every six months, increasing the likelihood that STDs are diagnosed and treated early and preventing new infections.”

Some researchers have been pushing the CDC to change the guidelines for STI testing among people on PrEP to increase their recommended frequency to every three months.

Centers for Disease Control and Prevention/2015 STD Surveillance Report

To read a press release about the study, click here.

To read a fact sheet about the report, click here.

To read the full report, click here.

To read the New York Times article, click here.