Sexually Transmitted Diseases

The World Health Organization estimated that 340 million new cases of curable STDs (limited to gonorrhea, syphilis, chlamydia, and trichomoniasis) occurred in the world in 1999 (Table 1). The largest number of new cases (incidence) occurred in the region of the world denoted by South and Southeast Asia. But, the highest prevalence (number of cases at any point in time per 1,000 population, ages fifteen to forty-nine) occurred in sub-Saharan Africa, meaning that at any random time during 1999, approximately 119 out of 1,000 persons, ages fifteen to forty-nine, were infected with one of these four STDs, or nearly one out of every nine people.

To understand why the global distribution of STDs is so highly differentiated and why cases occur in such geographically and culturally focal patterns is not a straightforward challenge. There are so many factors involved from which to hypothesize, even in industrialized countries. Two recent surveys of sexual behavior conducted in the United States and United Kingdom, where STD and HIV rates are lower, provide useful information, and clues, for comparison purposes. In both countries, the overwhelming majority of the population does not engage in high-risk sexual behaviors. Both surveys reported nearly identical mean numbers of sexual partners, but, in the United States, there were greater proportions of those who reported no or a high number of sex partners, and further, sexual behaviors and attitudes were more polarized in the United States. It was conjectured that the higher rates of STDs, including HIV, in the United States were attributable to the higher proportion of the population with greater numbers of sex partners and to restricted attitudes toward sexuality that made prevention efforts difficult (Michael 1998).

Because not all STDs are widely reportable in many countries, the task of understanding the worldwide epidemiologies of STDs is made more complex. Data on STDs from most of the world is incomplete at best, and in industrialized nations, is limited. In general, data on STDs from many European countries, the United States, Australia, and New Zealand showed increasing incidences of STDs in the 1960s and 1970s, with the bacterial TABLE 1

STDs leveling off then declining since then, but the viral STDs continuing to increase. Of course, the extent of diagnoses and the technologies available to make diagnoses must be seriously taken into consideration in any examination of temporal STD trends. Syphilis probably fluctuates in incidence more widely than any other STD, with cyclic epidemics, in particular, seen in the United States nearly every decade since the discovery of penicillin. Since the dissolution of Russia, an explosive outbreak of STDs has occurred in its respective states, including large syphilis epidemics in the late 1990s in Belarus, Ukraine, and Kyrgyzstan (Eng and Butler 1997).

Openness about sexuality may be a crucial factor in prevention of STDs, an observation from industrialized nations that may be applicable to developing countries. For example, Scandinavia and some northern and western European countries have levels of sexual activity comparable to those reported in the United States, but these countries report much lower rates of unintended pregnancies and STDs. This may be attributable to the pragmatic, open attitudes toward sexuality in these countries that are manifested in mass media interventions, school-based sexual education, and public discussion about sexual health. It can be hypothesized that this openness also translates into openness between parent and child, and between sex partners. This may be relevant to understanding relative low STD and unintended pregnancy rates observed in these countries.

Another possible factor that may partially explain differences in STD rates among industrialized countries is access to medical care. In the United States, many young people who are at elevated risk for STDs do not have medical care, and thus do not routinely access clinical services where regular STD screening tests and counseling can occur. This factor is given credibility by the scant differences in viral STD rates between the United States and other industrialized countries, and larger differences in rates of curable STDs. Other possible factors include the higher use of crack cocaine in the United States, often strongly associated with STD risk, occurrences of sexual violence toward women, and the lack of regulation, or legalization, of prostitution in the United States.