Sexually Transmitted Diseases, 2005
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 2005, 12,187 chlamydia cases (248 per 100,000 population) were reported, representing a 5% increase from 2004 (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 (1,496 per 100,000 population), with the next highest rate among 15 to 19-year-olds (989 per 100,000). The incidence of chlamydia among adults 25 to 29 years of age (620 per 100,000) is considerably lower but has increased in recent years. The chlamydia rate among females (355 per 100,000) is more than twice the rate among males (138 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 (1,535 per 100,000 population) is over 13 times higher than the rate among whites (115 per 100,000). Although blacks comprise approximately 4% of Minnesota’s population, they account for 26% of reported chlamydia cases. Rates among Asian/Pacific Islanders (282 per 100,000), American Indians (512 per 100,000), and Hispanics (624 per 100,000) are over two to five times higher than the rate among whites.
Chlamydia infections occur throughout the state, with the highest reported rates in Minneapolis (717 per 100,000 population) and St. Paul (598 per 100,000). In 2005, the greatest increases for chlamydia have been seen in the suburbs and Greater Minnesota with increases of 9 percent and 6 percent respectively.
Gonorrhea, caused by Neisseria gonorrhoeae, is the second most commonly reported STD in Minnesota. In 2005, 3,481 cases (71 per 100,000 population) were reported, representing an increase of 18% from 2004 (Table 3).
Adolescents and young adults are at greatest risk for gonorrhea (Table 4), with incidence rates of 213 per 100,000 population among 15 to 19-year-olds, 320 per 100,000 among 20 to 24-year olds, and 199 per 100,000 among 25 to 29-year-olds. Gonorrhea rates for males (65 per 100,000) and females (77 per 100,000) are comparable. Communities of color are disproportionately affected by gonorrhea, with 45% of cases reported among blacks. The incidence of gonorrhea among blacks (775 per 100,000) is approximately 35 times higher than the rate among whites (23 per 100,000). Rates among American Indians (118 per 100,000) and Hispanics (85 per 100,000) are approximately four to five times higher than among whites. The rate among Asian/Pacific Islanders (31 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 (333 per 100,000 population) is nearly 1.5 times the rate in St. Paul (238 per 100,000), seven times higher than the rate in the suburban metropolitan area (46 per 100,000), and 15 times higher than the rate in Greater Minnesota (22 per 100,000).
Quinolone-resistant Neisseria gonorrhoeae
While the overall rate of gonorrhea has stayed relatively constant over the past 3 years, the prevalence of quinolone-resistant N. gonorrhoeae (QRNG) has increased approximately five-fold from 1.4% in 2003 to 6.8% in 2005. 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, to 26.9% in 2004, and to 30% in 2005. 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
Although the incidence of primary/secondary syphilis in Minnesota is lower than that of chlamydia or gonorrhea (Table 3), the rate almost tripled in 2005. Seventy cases of primary/secondary syphilis (1.4 per 100,000 population) were reported in 2005 compared to 27 (0.5 per 100,000 population) cases in 2004.
In 2005, the number of early syphilis cases increased by 142 percent with 116 cases occurring in 2005 compared to 48 cases in 2004. The incidence in particular, is the highest amongst men who have sex with men (MSM). Of the 116 early syphilis cases in 2005, 109 (94%) occurred among men; 100 (92%) of these men reported having sex with other men; 38% of the MSM diagnosed with early syphilis were co-infected with HIV.
Two cases of congenital syphilis were reported in Minnesota in 2005 (Table 3).
Chancroid continues to be very rare in Minnesota. No cases were reported in 2005.
Note: For up to date information see: Sexually Transmitted Diseases (STDs)