09 November 2005

STD Statistics: Identity Matters.

There is mixed news in the effort to defeat sexually transmitted diseases (STDs). Total STD numbers are down but a serious outbreak of syphilis among gay men engaging in high risk sexual activity is a cause for concern, as is a remarkable disparity in infection rates between minorities, especially African-Americans, and whites, probably due to multiple factors.

The three STDs discussed below are all bacterial infections. AIDs is an STD caused by the HIV virus, and most cases of cervical cancer are caused by the HPV virus.

The nation's gonorrhea rate fell to 113.5 cases per 100,000 people last year, the lowest level since the government started tracking cases in 1941, according to the Centers for Disease Control and Prevention.

At the same time, health official saw increases in syphilis, which is far more rare but has been increasing since 2000. The rate of reported early-stage syphilis was 2.7 cases per 100,000 in 2004, up 29% since 2000.

The chlamydia rate rose to 319.6 cases per 100,000 in 2004, up about 6% from the year before. . . .

In 2004, about 64% of reported early-stage syphilis infections occurred among men who had sex with men, up from 5% in 1999, according to the CDC.

"It's very clear that for the last four years, when we've seen an increase it's primarily been in men and predominantly in men who have sex with men," Valdiserri said. "We know that's being fueled by increases in high-risk sexual behavior. We have good data to substantiate that. . . .

"As for chlamydia, a urine screening test is becoming increasingly common, and health officials are working to make chlamydia screening routine in yearly gynecological exams for sexually active young adult women.

Chlamydia is the most common of the three diseases. A total of 930,000 cases were reported last year. But health officials believe as many as 2.8 million new cases may actually be occurring each year.

About 330,000 cases of gonorrhea — once known as "the clap" — were reported in 2004. The CDC said there may really be as many as 700,000 cases of that disease each year.

Syphilis, a potentially deadly disease that first shows up as genital sores, has become relatively rare in the United States, with about 8,000 cases reported in 2004. Detection is believed to be much better for that disease, and the total number of annual cases is probably no more than 10,000.

Infection rates for all three diseases vary from state to state and city to city. Rates generally are highest in the Southeast — Mississippi, Louisiana and South Carolina have the highest gonorrhea rates, while Mississippi, Alaska and Louisiana have the highest rates of chlamydia. Among cities, Detroit and St. Louis lead both categories.

The article doesn't say so, but, in fact, race is a very significant factor in STD rates. The actual report bears this out (citations within quoted materials in this post are omitted):

In 2004, the rate of chlamydia among African-American females in the United States was more than 7 times higher than the rate among white females (1,722.3 and 226.6 per 100,000, respectively). The chlamydia rate among African-American males was more than 11 times higher than that among white males (645.2 and 57.3 per 100,000 population, respectively). . . .

In 2004, 69.6% of the total number of cases of gonorrhea reported to CDC occurred among African-Americans. In 2004, the rate of gonorrhea among African-Americans was 629.6 cases per 100,000 population, among American Indian/Alaska Natives the rate was 117.7, and among Hispanics the rate was 71.3. These rates are 19, 4, and 2 times higher, respectively, than the rate among whites in 2004 of 33.3 cases per 100,000 population. The rate of gonorrhea among Asian/Pacific Islanders in 2004 was 21.4 cases per 100,000 population . . . .

In 2004, 41% of all cases of P&S syphilis reported to CDC occurred among African-Americans and 40% of all cases occurred among non-Hispanic whites. The 2004 rate for African-Americans was 6 times greater than the rate among non-Hispanic whites . . . .

In 2004, 16% of all cases of P&S syphilis reported to CDC occurred among Hispanics. The rate of P&S syphilis among Hispanic men increased 12% (from 4.9 to 5.5 cases per 100,000 population) between 2003 and 2004. The rate among Hispanic women remained essentially unchanged (0.7 cases per 100,000 population). The rate among Hispanics in 2004 was 2 times greater than the rate among non-Hispanic whites.

Race is a factor even within the subgroup of men who have sex with men:

In 2004, by race/ethnicity, urethral gonorrhea [Ed. i.e. in the penis] positivity was 11% . . . in whites, 16% . . . in African-Americans, and 9% . . . in Hispanics. Rectal gonorrhea positivity was 7% . . . in whites, 6% . . . in African-Americans, and 5% . . . in Hispanics. Pharyngeal [Ed. i.e throat] gonorrhea positivity was 6% . . . in whites, 7% . . . in African-Americans, and 4% . . . in Hispanics . . . .

In 2004, a median of 59% . . . of MSM visiting STD clinics in the project and not previously known to be HIV-positive were tested for HIV; median HIV positivity was 4% . . . . HIV positivity varied by race and ethnicity, but was higher in African-American and Hispanic MSM. HIV positivity was 3% . . . in whites, 7% . . . in African-Americans, and 7% . . . in Hispanics.

In 2004, median HIV prevalence among MSM, including persons previously known to be HIV-positive and persons testing HIV-positive at their current visit, was 11% . . . . HIV prevalence was 11% . . . in whites, 16% . . . in African-Americans, and 11% . . . in Hispanics. . . .

Urethral chlamydia was 5% . . . in whites; 9% . . . in African-Americans, and 6% . . . in Hispanics . . .

Between 2000 and 2004, there was a 90% increase in the number of P&S syphilis cases among men and a 49% decrease in the number of cases among women

Syphilis has natural 8-11 year cycles related to the bacteria itself, which are part of the trend, but factors such as the shift from syphilis as a predominantly hetrosexual STD to a predominantly gay male phenomena, shows that the natural cycle is only one piece of growing rates of infection.

The government reports that form the basis for the story cited can be found here.

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