Sexually transmitted diseases (STD) are a wide ranging group of diseases and can have severe repercussions on the affected person. The range of STD - apart from the more common ones like herpes, gonorrhoea and syphilis - includes chancroid, trichomoniasis, candidiasis and non-specific urethritis. These are transmitted from person to person primarily through sexual contact.
STDs are associated with significant morbidity and health care costs.
In 1994, it was estimated that there were 2.5 billion sexually active people in the world, who engage in 100 million couplings daily, yielding 350,000 new cases of STDs.
The USA has the highest incidence of sexually transmitted diseases (STDs) in the world, even if AIDS is excluded. Half of the 10 most common American diseases are STDs. A estimated 15 million Americans become infected with sexually transmitted diseases (STDs) each year. Adolescents account for 25% of new cases and women suffer disproportionately from STD complications. The majority of these STDs are asymptomatic at the time they are acquired, and approximately half are lifelong infections.
Sexually transmitted diseases, particularly syphilis, gonococcal infections and non-gonococcal urethritis, are among the most frequently occurring in the world; they are exceeded only by influenza during epidemics, malaria and schistosomiasis. In some countries with well-established health services, the evolution of STD over the last 10 to 15 years follows a steadily rising curve. For instance, in the USA about 800,000 cases of gonococcal infections were notified in 1973; the present total exceeds 2.5 million out of a population of 250 million. There is good reason to believe that the same increase is true of other countries. Studies of the distribution by age-group in several countries bring out an even more important point. The prevalence of STD in the 15-19 age group is twice as high as in the whole population; in the age-group 20-24 it is four or five times as high, and in the 20-29 age-group it is twice as high (these figures relate to the USA). 36 percent of young people visiting hospital in a 1990 Kenyan study had an STD.
Since 1975 an increasing number of countries have reported a significant increase in syphilis transmission. This trend had been expected as a result of the universal tendency to replace penicillin by other antibiotics in the initial treatment of gonorrhoea. The epidemic trend of gonococcal infections has been declining in some countries after reaching a peak about 1974-1975, but this decline has often been more than compensated for by an increase in the incidence of nongonococcal genital infections, the latter now being more common in nearly all countries.
Particular attention is being paid to certain serotypes of Chlamydia trachomatis, which are associated with 35-50% of all cases of nongonococcal urethritis and cervicitis; there is strong evidence that some of the sequelae attributed to gonococcal infections (for example, salpingitis, peritonitis, infertility) could also be caused by C. trachomatis. The perinatal transfer of this agent may cause inclusion conjunctivitis (usually self-limited) in 30-40% and pneumonitis in about 15% of infants born to infected mothers.
Of grave importance is the increasing rise of genital wart virus infection, caused by papillomaviruses. There is strong evidence linking HPV, especially types 16 and 18 HPV DNA with cervical neoplasia. It is now realized that human immuno-deficiency virus infection (HIV) and AIDS is to a very large extent sexually transmitted, being seen heterosexually transmitted in Africa, Asia and Latin America, and in the majority of cases, homosexually transmitted in Europe, North America and Australia, but with the potential for heterosexual transmission throughout the world.
The prevalence of sexually transmitted infections has skyrocketed in the former Soviet bloc region in recent years, indicating that many people are having unprotected sex with non-monogamous partners. If HIV were to spread from drug-inject-ing populations into this larger population, it would find fertile ground for a much wider expansion.
Sexually transmitted infections are not uncommon in the Eastern Mediterranean region. It is estimated that around 10 million cases occur in the region every year, although reporting rates are low - fewer than 6% of that number were reported in 1998. STI rates are particularly high among young adults and in urban areas. Sexually transmitted infections are an important indicator that high-risk sexual practices do exist in the region, as national behavioural surveys confirm.