There was an estimated 376.4 million curable cases of chlamydia, gonorrhea, syphilis, and trichomoniasis contracted in 2016 which was similar to 2012, according to W.H.O’s analysis of over 100 studies. Trichomoniasis was the most common globally with an estimated 156 million infections, followed by chlamydia with 127.2 million cases, gonorrhea with 86.9 million cases, and syphilis with 6.3 million cases. Trichomoniasis was the most common STI among women affecting about 5% of all women worldwide, and chlamydia was the most common affecting almost 4% of all men worldwide.
Estimates from the US CDC do not include trichomoniasis currently, the latest reports include nearly 2.3 million cases of chlamydia, gonorrhea, and syphilis cases diagnosed in 2017.
STI’s do not always cause symptoms in many individual cases which allows them to spread undetected. As such it is always recommended to use condoms to help protect against infection, and regular STI screening is also recommended for sexually active individuals, especially for those in higher risk groups including younger people and the elderly in which the rates of infection continues to grow.
