There are more than 1 million new cases of curable STIs every day, according to new WHO data. Across four diseases — chlamydia, gonorrhea, trichomoniasis, and syphilis — this translates to nearly 380 million cases globally every year. Researchers looked through studies between 2009 and 2016 to estimate the prevalence of these STIs in those aged 15-49 and found that of these four diseases, trichomoniasis was most common in women while chlamydia was most common in men. Trichomoniasis also accounted for the majority of the STIs worldwide, followed by chlamydia, gonorrhea, and syphilis. And compared to 2012 estimates, rates of trichomoniasis in women have increased, while chlamydia incidence has decreased. The prevalence of gonorrhea has increased in men, while the other three diseases have remained stable.