The rates of sexually transmitted diseases among gay men have surged in France in the past two years, a new report from the France Public Health agency found Tuesday in preparation for Thursday’s World AIDS Day.

Gay men in France have seen a 100 percent spike in new cases of gonorrhea compared to 2013, a 56 percent increase in syphilis and a 47 percent jump in rectal chlamydia, according to France24. At the same time, the rate of HIV infection has remained alarmingly high but stable compared to 2013 levels, with 6,000 new cases reported in France last year. Meanwhile, HIV transmission rates have declined for straight men and women, according to the report.

The STD rise and stability of HIV infection can be attributed to high-risk sexual behavior and medical professionals neglecting to prescribe regular testing to their patients, French health officials said.

“The lack of decline in new HIV positive cases among [gay men] … the increase of STD infections and the augmentation of risky behavior constitute a strong set of indicators that prevention must be pursued among this population using all available tools,” the report said. “That is the major challenge of the current campaign targeting men who have sex with men.”

France is not alone in its surge of STDs and STIs (sexually transmitted infections). A recent STD Surveillance Report from the Centers for Disease Control and Prevention found that rates of chlamydia, gonorrhea and syphilis in the United States had risen between 2014 and 2015 to an all-time high. That included a 19 percent rise in syphilis, a 12.8 percent increase in gonorrhea and a 5.9 percent rise in chlamydia. The roughly 20 million STD and STI infections each year cost the U.S. healthcare system about $16 billion a year, mostly because many cases are not tested for and therefore go undiagnosed.