Gonorrhea rates rising among hardest-hit

HIV infection implications are ominous

At the very time when the nation’s syphilis infection rates are declining and new tests make it easier to detect and treat chlamydia, there is a dark cloud on the horizon: More than 60% of the cities that have been hardest hit by gonorrhea infection have experienced increases in the infection rate between 1999 and 2000.

"We see with gonorrhea data continuing challenges with controlling the epidemic," says Ronald O. Valdiserri, MD, MPH, deputy director of the National Center for HIV, STD, and TB Prevention of the Centers for Disease Control and Prevention in Atlanta. Valdiserri and other CDC officials presented the latest STD research and surveillance data at the National STD Prevention Conference, held March 4-7 in San Diego. "There are 650,000 new cases of gonorrhea every year in the United States," Valdiserri says. "But there also are positive indications that some communities have been able to dramatically reduce new infections."

The increases in gonorrhea infection bodes ill for future HIV infection rates because of the connection between STD infection and increased risk for HIV infection. "It’s a very important point, and it bears repeating, that STD treatment contributes to HIV prevention," Valdiserri says. "A number of studies have documented that having an untreated STD — for someone who’s living with HIV — makes the person more infectious to a sexual partner."

Likewise, a person who has an untreated STD and is exposed to HIV has a higher risk of becoming infected with HIV, Valdiserri adds. "This generally is true not just with gonorrhea, but also with inflammatory STDs, which increase the effectiveness of HIV by two- to fivefold," Valdiserri says.

Measuring HIV incidence remains difficult

Whether increases in gonorrhea rates will lead to increases in HIV rates remains to be seen, and at the present it would be difficult to measure, Valdiserri says. "We are challenged in our ability to measure the number of new HIV infections in the United States, and we’re in the process of developing better ways of measuring HIV incidence," Valdiserri says. "But having said that, we’re not seeing increases nationally, although we are extremely concerned about the possibility of increases, particularly in men-who-have-sex-with-men [MSM] populations."

Research and surveillance data presented at the STD conference were mixed. In 2000, syphilis rates fell in 15 of 20 cities that had the highest syphilis rates in 1999, says Susan DeLisle, ANRP, MPH, chief of the program development and support branch of the CDC Division of STD Prevention.

There were declines in syphilis rates of greater than 50% in Tulsa, OK, St. Louis, Richmond, VA, and New Orleans, while there were increases in syphilis rates in Chicago, Detroit, Miami, Newark, NJ, San Antonio, and San Francisco, DeLisle says. "Increases in some areas remind us that continued vigilance is required in every community if we hope to eliminate this disease," DeLisle says. Nationally, the syphilis rate declined from 2.4 cases per 100,000 to an all-time low of 2.2 cases per 100,000 in 2000, DeLisle adds.

At least one abstract presented at the conference indicates that the pockets of increased syphilis rates within the context of an overall decline by 90% in the past decade are the result of increases of syphilis infection among MSM.1

Rise in syphilis may indicate increase in HIV

"Because syphilis increases the likelihood of acquiring and transmitting HIV infection, and because a large proportion of MSM with syphilis in these outbreaks are HIV-positive, the rise in syphilis among MSM may indicate an increase in the incidence of HIV infection," the abstract states.

Another abstract showed that while primary and secondary syphilis rates declined dramatically in New York City from 58.2 per 100,000 in 1990 to 1.67 per 100,000 in 2000, there has been an increase in the number of syphilis cases among MSM, and many in this population are co-infected with HIV.2

Some findings suggest an increase in high-risk behaviors among MSM, such as studies showing a resurgence of gonorrhea and syphilis among MSM in Chicago and Boston and an abstract detailing the practice of "barebacking" (having unprotected anal sex with a non-primary partner) in San Francisco.3,4,5

Increases in infection rates of genital herpes (HSV-2) and human papilloma virus (HPV) among MSM populations also are major concerns, says Stuart Berman, MD, chief of the epidemiology and surveillance branch of the CDC’s Division of STD Prevention. "More than 6.5 million people become infected with genital herpes and HPV each year," Berman says. "In the United States, 38% of MSM have been infected with HPV type 16, and this is five times the heterosexual male rate and twice the rate of women."

HPV-16 exposure can cause serious problems for a person who has HIV and whose immune system is compromised, Valdiserri says. This is why the CDC is concerned about anal cancer among HIV-infected MSM populations. "We certainly want to get the message out to sexually active MSM that exposure to this virus has been associated with increased rates of anal cancer," Valdiserri says. Also, the prevalence of HSV-2 is higher among MSM than among other men, with rates of 31% vs. 18%, although the difference was not statistically significant in a study that surveyed people ages 17 to 59 from 1988 to 1994.6

The study concluded that MSM are at higher risk for HPV-16 and probably are at higher risk for HSV-2 infection, although the latter has not been proved. "Herpes remains a very important problem in the United States," Berman says. "One in five Americans are infected with genital herpes, and men and women who have herpes are five times more likely than uninfected individuals to acquire HIV infection if they’re exposed to that virus in sexual contact."

Because chlamydia traditionally has been associated with severe reproductive health consequences for women and because it’s easier to diagnose in women, it hasn’t been routinely screened among men, but this could change, DeLisle says. There’s a urine test now available, whereas before men would have had to subject themselves to a urethra swab, DeLisle says. In studies where men are being tested, there are double-digit rates of chlamydia infection among men in the 20-24 age group and among women in the 15-19 age group.

"With the availability of technology that allows for broader screening, we should have additional data," DeLisle says.

References

1. McLean C, DeSimone G, Calvet H, et al. Changing epidemiology of syphilis and other sexually transmitted diseases among men who have sex with men. Presented at the National STD Prevention Conference. San Diego; March 4-7, 2002. Abstract 272.

2. Paz-Bailey G, Meyers A, Markowitz L, et al. Changes in the epidemiology of syphilis in New York City, 1999-2001. Presented at the National STD Prevention Conference. San Diego; March 4-7, 2002. Abstract 444.

3. Ciesielski CA, Flynn J, McLean C. Sexually transmitted diseases, HIV testing, and HIV risk behaviors among men who have sex with men seeking care at Howard Brown Health Center. Presented at the National STD Prevention Conference. San Diego; March 4-7, 2002. Abstract 321.

4. Golub SA, Mayer K, Lo W, Cohen D. Patterns of STD infection, HIV coinfection, and risk-behavior among MSM at a Boston community health center. Presented at the National STD Prevention Conference. San Diego; March 4-7, 2002. Abstract 418.

5. Mansergh G, Marks G, Colfax G, et al. Barebacking’ in a diverse sample of MSM. Presented at the National STD Prevention Conference. San Diego; March 4-7, 2002. Abstract 403.

6. Xu F, Sternberg MR, Karem K, et al. Association between MSM behavior and the seroprevalence of HPV-16 and HSV-2. Presented at the National STD Prevention Conference. San Diego; March 4-7, 2002. Abstract 354.