Home
Search
About AVERT
Donate here
Help & advice
Contact us
Links

Cases of sexually transmitted diseases reported by state health departments and rates per 100,000 civilian population: United States, 1996-2003

Statistics for HIV and AIDS in the USA can be found in our statistics section.

STD reporting

In the United States, the reporting of national surveillance data on Sexually Transmitted Diseases (STDs) does not include all of the most common STDs.

Reporting for gonorrhea and syphilis has been undertaken since 1941, but chlamydia has only been reported since 1984. The reporting of chlamydia was established when public programmes for the screening and treatment for women were set up, to help prevent a complication of chlamydia called Pelvic Inflammatory Disease (PID).

There is no data reporting for genital herpes, genital warts or non-specific urethritis (NSU). Data for these diseases are limited to estimates of the number of initial visits to private physicians' offices, as provided by the National Disease and Therapeutic Index (NDTI).

STDs and gender

STD statistics can often show an unequal gender distribution, usually with more females being infected.

Among the chlamydia diagnoses reported in 2003, the male to female bias was 190,723 to 686,755. For gonorrhea, the male to female ratio was 160,459 to 174,645. As these data demonstrate, the gender divide between men and women with chlamydia is significantly greater than that between those infected with gonorrhea. The significant number of women who are screened for chlamydia can explain this gender difference to a large extent.

In 2003, the numbers of female and male diagnoses of primary and secondary stage syphilis were 5,959 and 1,218 respectively. This is the only one of the three main STDs reported which has more male than female cases. This can be attributed to some extent to outbreaks amongst men who have sex with men (MSM).

Chlamydia

Increasing numbers of chlamydia infections have made it the most widespread STD in the USA. In 1996 there were 492,631 reported diagnoses, corresponding to a rate of 190.6 per 100,000 population. However, by 2003 the annual total had increased by 78% to 877,478 and the rate per 100,000 had risen to 304.3.

Cases of chlamydia have increased every single year bar one since reporting began in 1984. As well as possible increases in high-risk sexual behaviours, this rise can be attributed to the expansion of chlamydia screening activities, use of more sensitive screening tests, and improvements in the reporting system.

Despite progress being made, many women who are at risk are still not being tested. This is partly due to lack of awareness among some health care providers and the limited resources available to support screening.

Gonorrhea

In 1978, the annual number of reported gonorrhea diagnoses reached a record high of 1,013,436 - a rate of 459.7 per 100,000. Following decreases each year between 1985 and 1997, the annual number of cases has stayed below 365,000, and the rate below 130. True increases or decreases may be masked by changes in screening practices (affected by simultaneous testing for chlamydia), use of diagnostic tests with different sensitivities, and changes in reporting practices.

Although the 2003 rate of 116.2 diagnoses per 100,000 population is the lowest ever recorded, gonorrhea remains the second most commonly reported STD in the United States.

Syphilis

Numbers of reported primary and secondary syphilis diagnoses have varied widely since reporting began, from a high of 94,957 in 1946 to a low of 5,979 in 2000. This represents a change from 70.9 cases per 100,000 population to 2.1 cases. Numbers did rise back up to 55,397 in 1990 before decreasing each year in the 1990s. Since the turn of the millennium, there has been another rise to 7,177 cases in 2003. This increase is entirely due to more diagnoses in men, as the number of women diagnosed continues to fall.

Due to the low numbers involved, the Surgeon General announced in 1999 a plan to eliminate syphilis from the USA. Syphilis is a localised infection, with 80% of counties reporting no cases at all. Syphilis remains a problem in the South and increasingly in urban areas with large populations of men who have sex with men (MSM). Several outbreaks of syphilis have recently been reported in this latter group, possibly reflecting increases in high-risk sexual behaviour. This problem is not confined to the USA, however, and has been reported in similar population groups in the UK.

For more information about sexually transmitted diseases, see our STD section.

Last updated December 15, 2004