title: Global Estimates of the Prevalence and Incidence of Four Curable Sexually Transmitted Infections in 2012 Based on Systematic Review and Global Reporting.
abstract: BACKGROUND
  Quantifying sexually transmitted infection (STI) prevalence and incidence is important for planning interventions and advocating for resources. The World Health Organization (WHO) periodically estimates global and regional prevalence and incidence of four curable STIs: chlamydia, gonorrhoea, trichomoniasis and syphilis.
  
  
  RESULTS
  WHO's 2012 estimates were based upon literature reviews of prevalence data from 2005 through 2012 among general populations for genitourinary infection with chlamydia, gonorrhoea, and trichomoniasis, and nationally reported data on syphilis seroprevalence among antenatal care attendees. Data were standardized for laboratory test type, geography, age, and high risk subpopulations, and combined using a Bayesian meta-analytic approach. Regional incidence estimates were generated from prevalence estimates by adjusting for average duration of infection. In 2012, among women aged 15-49 years, the estimated global prevalence of chlamydia was 4.2% (95% uncertainty interval (UI): 3.7-4.7%), gonorrhoea 0.8% (0.6-1.0%), trichomoniasis 5.0% (4.0-6.4%), and syphilis 0.5% (0.4-0.6%); among men, estimated chlamydia prevalence was 2.7% (2.0-3.6%), gonorrhoea 0.6% (0.4-0.9%), trichomoniasis 0.6% (0.4-0.8%), and syphilis 0.48% (0.3-0.7%). These figures correspond to an estimated 131 million new cases of chlamydia (100-166 million), 78 million of gonorrhoea (53-110 million), 143 million of trichomoniasis (98-202 million), and 6 million of syphilis (4-8 million). Prevalence and incidence estimates varied by region and sex.
  
  
  CONCLUSIONS
  Estimates of the global prevalence and incidence of chlamydia, gonorrhoea, trichomoniasis, and syphilis in adult women and men remain high, with nearly one million new infections with curable STI each day. The estimates highlight the urgent need for the public health community to ensure that well-recognized effective interventions for STI prevention, screening, diagnosis, and treatment are made more widely available. Improved estimation methods are needed to allow use of more varied data and generation of estimates at the national level.
authors.affiliation: Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
authors.forename: Lori
authors.initials: L
authors.lastname: Newman
authors.affiliation: Consultant to Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
authors.forename: Jane
authors.initials: J
authors.lastname: Rowley
authors.affiliation: Consultant to Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.|Statistical Consulting Centre, University of Melbourne, Melbourne, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Vander Hoorn
authors.affiliation: Consultant to Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
authors.forename: Nalinka Saman
authors.initials: NS
authors.lastname: Wijesooriya
authors.affiliation: WHO Collaborating Centre for Gonorrhoea and other STIs, Department of Laboratory Medicine, Örebro University Hospital and Örebro University, Örebro, Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Unemo
authors.affiliation: Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland.
authors.forename: Nicola
authors.initials: N
authors.lastname: Low
authors.affiliation: Department of Health Statistics and Information Systems, World Health Organization, Geneva, Switzerland.
authors.forename: Gretchen
authors.initials: G
authors.lastname: Stevens
authors.affiliation: Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
authors.forename: Sami
authors.initials: S
authors.lastname: Gottlieb
authors.affiliation: Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
authors.forename: James
authors.initials: J
authors.lastname: Kiarie
authors.affiliation: Department of Reproductive Health and Research, World Health Organization, Geneva, Switzerland.
authors.forename: Marleen
authors.initials: M
authors.lastname: Temmerman
mesh_terms: D005260:Female; D014943:Global Health; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D012749:Sexually Transmitted Diseases / Q000188:drug therapy / Q000453:epidemiology*