Sexually transmitted diseases (STDs) are diseases resulting from unprotected sexual contact. Examples of diseases that can be transmitted sexually include syphilis, gonorrhea, Chlamydia trachomatis, hepatitis B, hepatitis C, human immunodeficiency virus (HIV), genital herpes, and human papillomavirus (HPV). Co-infection with chlamydia and gonorrhea is not uncommon and infection with one STD can facilitate the transmission of another. Women and children often suffer from the most complications related to STDs such as pelvic inflammatory disease, infertility, ectopic pregnancy, and chronic pelvic pain. Medically underserved populations and youth carry a disproportionate share of STDs. Early detection and treatment is contingent upon availability of, appropriateness of, and access to services.

gonorrhea

• Incidence rates for gonorrhea are declining sharply in San Mateo County, as they are both statewide and nationwide. In 1990, the San Mateo County incidence rate was 125.3 cases per 100,000; in 1997, the case rate was 18.6 per 100,000. The San Mateo County rate has remained well below the state (59.0 per 100,000) and national (124.0 per 100,000) rates, and continues to satisfy the Year 2000 objective by a wide margin (225 or fewer per 100,000). ⁶⁴²

Chlamydia

• Unlike state and national rates, San Mateo County incidence rates for chlamydia have shown a consistent decline since 1990 (250.8 per 100,000 in 1990; 119.6 per 100,000 in 1997). Whereas San Mateo County once exceeded state and national incidence rates for chlamydia, the county is now well below those rates and satisfies the Year 2000 objective (170 or fewer per 100,000), as well. However, most reported cases are in females and very little testing occurs in males. Aggressive testing and control measures would find rates much higher than the Year 2000 objective. ⁶⁴³

syphilis

• The incidence of syphilis in San Mateo County is low and remains steady (6.0 cases per 100,000 in 1996, 5.4 in 1997). State and national rates are considerably higher (13.6 and 20.2 per 100,000, respectively, in 1996), but are sharply declining. ⁶⁴⁴

   

• The 1997 San Mateo County incidence for primary and secondary syphilis was 0.9 per 100,000 population. Again, the state and U.S. rates are higher (1.6 and 4.3 per 100,000, respectively) but are declining. ⁶⁴⁵

Refer to Adolescent Sexual Activity page  for findings relating to adolescent sexual behavior.

tuberculosis

• San Mateo County had the 15th highest tuberculosis (TB) rate among the 58 California counties between 1994 and 1996. ⁶⁴⁶

• The 1997 San Mateo County incidence rate for tuberculosis was 12.0 per 100,000 population. This rate is comparable to the state rate (11.8 per 100,000), but above the national rate (8.0 in 1996). The San Mateo County rate, however, is far from reaching the Year 2000 objective (3.5 or fewer cases per 100,000 population). ⁶⁴⁷

• Whereas U.S. and California rates are declining, San Mateo County TB incidence rates continue to increase. The 1997 number of TB cases (85) represents a 165% increase over the number of 1985 cases(32).⁶⁴⁸

• The incidence of tuberculosis in San Mateo County disproportionately affects the non-White population. Asian/Other residents are particularly hard hit: over one-half (54.9%) of tuberculosis cases between 1985 and 1997 have been among Asian/Other residents (excludes White, African-American, and Hispanic), while Asians/Others only comprise 16.6% of the total county population.⁶⁴⁹

• The 1997 TB rate among Asians in San Mateo County was 37.7 per 100,000 population, more than twice the rate of any other group (17.7 among African-Americans, 10.7 among Hispanics, 2.9 among Whites). The Asian TB rate appears to be following a slight upward trend, although the rate has been rather steady for the past three years. ⁶⁵⁰

• The majority of San Mateo County TB cases are foreign-born; in 1997 82.4% of cases were among persons born outside the United States; this is the highest percentage recorded in more than a decade and significantly higher than the California rate of 60%.⁶⁵¹

• Of foreign-born San Mateo County TB cases between 1985 and 1997, one-half (50.2%) have come from persons immigrating from the Philippines. A total of 16% of foreign-born TB cases are among persons born in Mexico.⁶⁵²

663  Ibid.