Sexually transmitted infections (STIs) remain a public health problem of major significance in most parts of the world and are responsible for high morbidity, complications and sequelae. The exact magnitude of the global burden of STIs is not known. WHO estimates that about one million new cases of STIs occur daily in the world out of which about 400,000 new cases of STIs are estimated to occur daily in South and South-East Asia.
The appearance of HIV and AIDS has focused greater attention on the control of STIs. STI rates not only indicate the extent of unprotected sex, but also an individual with an STI is more vulnerable to contracting HIV than an individual who has no other STIs. Some STIs, when present, facilitate the transmission of HIV. A number of studies have implicated both ulcerative and non-ulcerative STIs to varying degrees, with relative risks ranging from 1.5 to 8.5. . Although the cofactor effect seems to be higher for ulcerative diseases, non-ulcerative infections could be more important in some populations because of their frequency and prevalence.