More than one million people every day worldwide catch a sexually transmitted infection, with rates of chlamydia, gonorrhea, trichomoniasis, and syphilis the most worrying, according to the World Health Organization. The vast majority of the infections are easily preventable and curable, but some diseases - in particular, gonorrhoea - are evolving into super-bug forms and that are increasingly difficult to treat with antibiotics.
"Sexually transmitted infections are everywhere. They are far more common than we think," Teodora Wi, a medical officer in the WHO's department for reproductive health and research, said.
The report, based on 2016 global data which are the latest available, showed that among men and women aged between 15 and 49 there were 127 million new cases of chlamydia in 2016, 87 million cases of gonorrhoea, 6.3 million cases of syphilis and 156 million cases of trichomoniasis.
Sexually transmitted infections, or STIs, are a "persistent and endemic health threat worldwide" and have a profound impact on both adult and child health, the WHO said. If they are left untreated, they can lead to serious and chronic health effects that include neurological and cardiovascular disease, infertility, ectopic pregnancy, stillbirths and an increased risk of HIV. Syphilis alone caused an estimated 200,000 stillbirths and newborn deaths in 2016, making it one of the leading causes of baby loss globally, the research said.
Peter Salama, the WHO's executive director for universal health coverage, said the data showed the need for "a concerted effort to ensure everyone, everywhere can access the services they need to prevent and treat these debilitating diseases".
Sexual infections caused by bacteria can normally be treated and cured with widely available medicines, but the WHO study said recent shortages in the global supply of benzathine penicillin had made it more difficult to control syphilis.
Rising drug resistance to gonorrhea treatments is also a growing health threat. Tim Jinks, a specialist in infectious disease at the Wellcome Trust global health charity, said the increase in cases of STIs was alarming, especially given that some antibiotics are becoming less effective due to drug resistance.
"The high numbers of cases of gonorrhoea are of particular concern," he said. "We are increasingly seeing incidences of so-called 'super-gonorrhoea' which are practically impossible to treat."
