Sexually transmitted infections among key populations in India: A protocol for systematic review.

Background: Sexually transmitted infections (STIs) are one of the leading causes of health, and economic burdens in the developing world, leading to considerable morbidity, mortality, and stigma. The incidence and prevalence of the four curable STIs viz. syphilis, gonorrhoea, chlamydia, and trichomoniasis vary remarkably across different geographical locations.