In 1996 the number of Americans with a new STI/year was estimated to be about 12 million. This number was recently revised to 18.9 million in 2000,1 a significant increase.
Adolescents and young adults are disproportionately affected. Nearly half (48%) of new STI cases occur among 15- to 24-year-olds each year, although they comprise only one fourth of the sexually active population.1
Human papilloma virus (HPV) is the most commonly acquired STI, followed by trichomoniaisis & chlamydia. These three account for 88% of all new adolescent/young adult cases (15-24).1 STI Estimate –
Although it is difficult to know the exact number of new cases of various STIs each year (called incidence) or the total number of individuals with existing infections in the population (called prevalence), some estimates based on various studies are shown here.
Note that HPV is the most common STI in terms of new cases each year. HPV is the primary cause of cervical cancer in women. Genital herpes (another viral infection), however, has the largest number of people infected in Americaan astounding 45 million or more.
STI Incidence * Prevalence **
HPV 5.5 million 20 million
Trichomoniasis 5million unknown
Chlamydia 3 million 2 million
Genital herpes 1 million 45 million
Gonorrhea 650,000 unknown
Syphilis 70,000 unknown
Hepatitis B 120,000 417,000
* Number of new infections occurring in the population in one year
** Number of infections found in the population including those from previous years
1. Centers for Disease Control and Prevention. Tracking the hidden epidemics 2000: Trends in STDs in the United States. http://www.cdc.gov/nchstp/od/news/RevBrochure1pdftoc.htm. [Accessed 1May04; 22Jul04, Medical Inst Advisory, http://www.medinstitute.org/July2204.htm]