The Centers for Disease Control and Prevention estimates that the United States sees 20 million new sexually transmitted infections (STIs) each year, with a total prevalence of 110 million, costing the country $16 billion in direct medical costs annually, CNN reports.  Included in the estimate are eight STIs: chlamydia, gonorrhea, hepatitis B virus (HBV), herpes simplex virus type 2 (HSV-2), HIV, human papillomavirus (HPV, which can cause genital warts and cervical cancer), syphilis and trichomoniasis. The CDC's estimates are conservative, suggesting that the actual figures may be even higher.  

The CDC's cost estimates are based on the direct medical cost across the lifetime of someone infected with one of the eight STIs, and they exclude indirect costs like loss of productivity or other intangibles such as pain and suffering. If included, the CDC reports, these additional costs would significantly raise the estimated financial burden of STIs in the U.S.

In descending order of incidence, the estimated number of annual new STI cases are: HPV, 14.1 million; chlamydia, 2.9 million; trichomoniasis, 1 million; gonorrhea, 820,000; HSV-2, 776,000; syphilis, 55,400; HIV, 41,400; and hepatitis B, 19,000.

Young Americans, ages 15 to 24, account for half of all new STIs.

To read the CDC report, click here.

To read the CNN report, click here.