Sexually Transmitted Diseases, 2004
Active surveillance for gonorrhea and chlamydia was initiated in January 2002. This involves cross-checking laboratory-reported cases against cases reported by clinicians. Although both laboratories and clinical facilities are required to report STDs independently of each other, an episode of STD is not considered a case for surveillance purposes until a corresponding case report is submitted by a clinical facility. Additionally, case reports contain critical demographic and clinical information that is not available from laboratory reports. When a laboratory report is received but no corresponding case report is received within 45 days, MDH mails a reminder letter and case report form to the corresponding clinical facility. Cases of syphilis and chancroid are monitored through a mostly passive surveillance system. Herpes simplex virus and human papillomavirus infections are not reportable.
Although overall incidence rates for STDs in Minnesota are lower than those in many other areas of the United States, certain population subgroups in Minnesota have very high STD rates. Specifically, STDs disproportionately affect adolescents, young adults, and persons of color.
Chlamydia trachomatis infection is the most commonly reported STD in Minnesota. In 2004, 11,601 cases (236 per 100,000 population) were reported, representing a 8% increase from 2003 (Table 3).
Adolescents and young adults are at highest risk for acquiring chlamydial infection (Table 4). The chlamydia rate is highest among 20 to 24-year-olds (1,372 per 100,000 population), with the next highest rate among 15 to 19-year-olds (968 per 100,000). The incidence of chlamydia among adults 25 to 29 years of age (597 per 100,000) is considerably lower but has increased in recent years. The chlamydia rate among females (343 per 100,000) is more than twice the rate among males (126 per 100,000). This difference is likely due to more frequent screening among women.
The incidence of chlamydia infection is highest in communities of color (Table 4). The rate among blacks (1,456 per 100,000 population) is 13 times higher than the rate among whites (113 per 100,000). Although blacks comprise approximately 4% of Minnesota’s population, they account for 25% of reported chlamydia cases. Rates among Asian/Pacific Islanders (260 per 100,000), American Indians (488 per 100,000), and Hispanics (594 per 100,000) are two to five times higher than the rate among whites.
Chlamydia infections occur throughout the state, with the highest reported rates in Minneapolis (694 per 100,000 population) and St. Paul (639 per 100,000). The incidence in the suburban metropolitan area (168 per 100,000) is similar to that in Greater Minnesota (149 per 100,000).
Gonorrhea, caused by Neisseria gonorrhoeae, is the second most commonly reported STD in Minnesota. In 2004, 2,957 cases (60 per 100,000 population) were reported, representing a decrease of 7% from 2003 (Table 3).
Adolescents and young adults are at greatest risk for gonorrhea (Table 4), with incidence rates of 198 per 100,000 population among 15 to 19-year-olds, 288 per 100,000 among 20 to 24-year olds, and 157 per 100,000 among 25 to 29-year-olds. Gonorrhea rates for males (51 per 100,000) and females (69 per 100,000) are comparable. Communities of color are disproportionately affected by gonorrhea, with 41% of cases reported among blacks. The incidence of gonorrhea among blacks (592 per 100,000) is approximately 27 times higher than the rate among whites (22 per 100,000). Rates among American Indians (89 per 100,000) and Hispanics (97 per 100,000) are approximately five times higher than among whites. The rate among Asian/Pacific Islanders (36 per 100,000) is similar to that among whites.
Gonorrhea rates are highest in the cities of Minneapolis and St. Paul (Table 4). The incidence in Minneapolis (276 per 100,000 population) is nearly 1.5 times the rate in St. Paul (190 per 100,000), seven times higher than the rate in the suburban metropolitan area (40 per 100,000), and 13 times higher than the rate in Greater Minnesota (21 per 100,000).
While the overall rate of gonorrhea has stayed relatively constant over the past three years, the prevalence of quinolone-resistant Neisseria gonorrhoeae (QRNG) has increased five-fold from 1.5% in 2002 to 8.4% in 2004. Of concern is the high prevalence among men who have sex with men (MSM), which has increased from 0% in 2002, to 8.9% in 2003, and 26.9% in 2004. As a result, fluoroquinolones (e.g. ciprofloxacin) are no longer recommended for treating gonorrhea in men with male sexual partners in Minnesota.
Surveillance data for primary and secondary syphilis are used to monitor morbidity trends because they represent recently acquired infections. Data for early syphilis (which includes primary, secondary, and early latent stages of disease) are used in outbreak investigations because they represent infections acquired within the past 12 months and signify opportunities for disease prevention.
Primary and Secondary Syphilis
The incidence of primary/secondary syphilis in Minnesota is lower than that of chlamydia or gonorrhea (Table 3). Twenty-seven cases of primary/ secondary syphilis (0.5 per 100,000 population) were reported in 2004.
The number of cases of early syphilis decreased in 2004 compared to 2003, however the number of cases among men who have sex with men (MSM) remained high. Forty-eight cases of early syphilis were reported in 2004, compared to 93 cases in 2003. Of the 48 early syphilis cases in 2004, 42 (88%) occurred among men; 34 (81%) of these men reported having sex with other men. Almost a third (32%) of the MSM diagnosed with early syphilis were co-infected with HIV. However, preliminary data for early syphilis cases in 2005 shows a return to 2003 levels. Similar patterns in syphilis among MSM have been observed in other parts of the Unites States.
One case of congenital syphilis was reported in Minnesota in 2004 (Table 3).
Chancroid continues to be very rare in Minnesota. No cases were reported in 2004.
Note: For up to date information on Sexually Transmitted Diseases see Sexually Transmitted Diseases (STDs)
Go to full issue: DCN, July/August 2005: Volume 33, Number 4