In 2016, the highest STI incidence rates were registered in Bayankhongor (36.5 cases per 10,000), Domod (34.7), Sukhbaatar (31.5), Khuvsgul (26.5), Govi-Altai (24.0), Tuv (23.7), Govisumber (23.6) and Domogovi (21.3) Aimags and Ulaanbaatar City (22.2). The morbidity of trichomoniasis was higher in Domod (60.7), Bayankhongor (53.3), Bulgan (17.5) and Sukhbaatar (15.8) Aimags and Ulaanbaatar City (15.4), and was higher there than the national average (14.3) and aimag average (13.3). The incidence of HIV infection has slowly increased in Mongolia since 2005.