ROBERT T. FRANCOEURIt is impossible to obtain reliable statistics about the incidence of STDs, because American physicians are only required by law to report cases of HIV and syphilis to the Centers for Disease Control and Prevention (CDC). Public clinics keep fairly reliable statistics, but many private physicians record syphilis and other STDs as urinary infections and do not report them to the CDC. A second, equally important factor leading to the lack of data is the number of persons infected with various STDs who are without symptoms and do not know they are infectious. This silent epidemic includes most males infected with candidiasis, 10 percent of males and 60 to 80 percent of females infected with chlamydia, 5 to 20 percent of males and up to 80 percent of females with gonorrhea, and many males and females with hemophilus, NGU, and trichomonas infections.
In 1995, the nation's three most commonly reported infections were sexually transmitted, according to statistics from the federal Centers for Disease Control and Prevention released in October 1996. Chlamydia, tracked for the first time in 1995, topped the list with 477,638 cases. Gonorrhea, the most commonly reported infectious disease in 1994 with 418,068 cases dropped to second in 1995 with 392,848 cases. AIDS dropped from second place in 1994 (78,279 cases) to third place in 1995 (71,547 cases). In 1995, five sexually transmitted diseases, chlamydia, gonorrhea, AIDS, syphylis, and hepatitis B, accounted for 87 percent of the total number of infectious cases caused by the top ten maladies. Chalmydia was more commonly reported among women, striking 383,956 in 1995; gonorrhea and AIDS were more common with men, with 203,563 and 58,007 cases, respectively.
The latest data suggest that the national incidence of gonorrhea and syphilis has continued to decline (U.S. Department of Health and Human Services 1994). Reported cases of gonorrhea peaked at a million cases in 1978 and declined to about 700,000 cases in 1990. With a realistic estimate suggesting two million new cases annually, gonorrhea is one of the most commonly encountered STDs, especially among the young. About 50,000 new cases of syphilis are reported annually; an estimated 125,000 new cases occur annually. Syphilis is primarily an adult disease, mostly concentrated in larger cities, and one of the least common STDs. The incidence of syphilis rose sharply between the late 1980s and the early 1990s, and then continued its more long-term decline. Congenital syphilis rates have decreased in parallel to declining rates of syphilis among women. Infants most at risk were born to unmarried, African-American women who receive little or no prenatal care. Syphilis and gonorrhea have consistently been more common in the southern states. Reasons for this are not well understood, but may include differences in racial and ethnic distribution of the population, poverty, and the availability and quality of health-care services.
Chlamydia is the most prevalent bacterial STD in the United States, with four million adults and possibly 10 percent of all college students infected. It is more common in higher socioeconomic groups and among university students. Prevention and control programs were begun in 1994, and are a high priority because of the potential impact on pelvic inflammatory disease (PID) and its sequelae, infertility and ectopic pregnancy. Twenty to 40 percent of women infected with chlamydia develop PID. Many states have implemented reporting procedures and begun collecting case data for chlamydia.
Three million new cases of trichomonas are reported annually, but probably another six million harbor the protozoan without symptoms. Fifteen million Americans have had at least one bout of genital herpes. About a million new cases of genital warts are reported annually.
STD rates continue to be much higher for African-Americans and other minorities than for white Americans, sixtyfold higher for blacks and fivefold higher for Latinos. About 81 percent of the total reported cases of gonorrhea occur among African-Americans, with the risk for 15- to 19-year-old blacks more than twentyfold higher than for white adolescents. Similarly, the general gonorrhea rate is fortyfold higher for blacks and threefold higher for Latinos than it is for white Americans. There are no known biologic reasons to explain these differences. Rather, race and ethnicity in the United States are risk markers that correlate with poverty, access to quality health care, health-care-seeking behavior, illicit drug use, and living in communities with a high prevalence of STDs.