BOX 3-8 Sexually Transmitted Diseases
Sexually transmitted diseases (STDs) remain a major public health problem in both industrialized and developing nations. If left untreated, these infections can lead to acute illness, infertility, long-term disability, and death, and nearly all STDs increase the likelihood of HIV transmission (Fleming and Wasserheit, 1999). The exact magnitude of the global STD burden is unknown (WHO, 2001d). This is due in part to poor data collection, a large number of infections that are asymptomatic, and only a portion of the symptomatic population seeking medical care are subsequently reported. The World Health Organization estimates that 340 million new cases of STDs—syphilis (12 million), chlamydia (92 million), gonorrhea (62 million), and trichomoniasis (174 million)—occurred worldwide in 1999. The largest number of new infections was seen in South and Southeast Asia, followed by sub-Saharan Africa, then Latin America and the Caribbean. Sub-Saharan Africa experienced the greatest incidence on a per thousand population basis (WHO, 2001d).
Chlamydia. South and Southeast Asia have the most new cases of infection with Chlamydia trachomatis (43 million) followed by sub-Saharan Africa (16 million) and Latin America and the Caribbean (9.5 million) (WHO, 2001d). Studies among pregnant women in India have shown a prevalence rate of 17 to 21 percent (Paul et al., 1999; Rastogi et al., 1999). Reported rates of chlamydia infection have increased steadily in the United States since 1984; in 2001, 278.3 cases per 100,000 people were reported. Increased reports of chlamydia infection during the 1990s reflect the expansion of chlamydia screening activities, use of increasingly sensitive diagnostic tests, increased emphasis on case reporting from providers and laboratories, and improvements in the information systems for reporting. Higher rates in the southern region of the United States likely reflect both an expansion of screening activities in the South and the high burden of disease in this region (CDC, 2002h; IOM, 1997).
Gonorrhea. The estimated number of new cases of infection with Neisseria gonorrhoeae among adults worldwide in 1999 was 62 million. South and Southeast Asia have the most cases (27 million) followed by sub-Saharan Africa (17 million) and Latin America and the Caribbean (7.5 million) (WHO, 2001d). A notable increase in gonorrhea rates has been seen in Eastern Europe, with the highest rates occurring in Estonia, Russia, and Belarus (111, 139, and 125 per 100,000 people, respectively). In the United States, gonorrhea rates peaked in 1975 (467.7 cases per 100,000) and declined following implementation of the national gonorrhea control program in the mid-1970s (CDC, 2001f). The 2001 rate of gonorrhea, 128.5 cases per 100,000 persons, far exceeds the Healthy People 2010 objective of 19 cases per 100,000 persons. Despite a decrease among African Americans, rates in this population remained extremely high (782.3 in 2001); rates were highest for African Americans aged 15 to 24 years (CDC, 2002h); African American women aged 15– 19 years had a gonorrhea rate of 3,495.2 cases per 100,000, 18 times higher than the rate among non-Hispanic white females of similar age.