What is the difference between “reported” and “estimated” STI cases?

“Reported” STI cases are those for which the results of a medical test have been reported at the local, state, or federal level. While STI reporting requirements and mechanisms have improved, they do have limitations. Even the best national STI reporting system falls far short of determining the actual number of STI cases. Here are some reasons:
– many STIs cause no symptoms at all or result in “delayed” symptoms
– for a variety of reasons, even when they have symptoms of an STI, some people still don’t seek medical care (e.g., they may not know where to go; they may not have the financial resources to pay for treatment; they may deny that they have symptoms)
– Doctors often treat patients for STIs without performing a laboratory test that would help them make a specific diagnosis
– Doctors and laboratories may fail to report patients with laboratory-confirmed STIs

Public Health officials are highly aware of the limitations of the reporting system, and consider all of these factors when they “estimate” the number of STI cases.1

For example, although just over 350 thousand cases of gonorrhea were reported in 2014, the CDC estimates  that approximately 820 thousand cases occur each year in the U.S.2

1. Centers for Disease Control and Prevention, “Reported STDs in the United States: 2014 National Data for Chlamydia, Gonorrhea, and Syphillis,” CDC Fact Sheet  http://www.cdc.gov/std/stats14/std-trends-508.pdf accessed May 2016.

2. Centers for Disease Control and Prevention, “Gonorrena – CDC Fact Sheet (Detailed Version)” http://www.cdc.gov/std/gonorrhea/STDFact-gonorrhea-detailed.htm   Accessed May 2016.


Updated: May 2016