A number of factors make people more susceptible to TB infections. The most important risk factor globally is HIV; 13% of all people with TB are infected by the virus.[39] This is a particular problem in sub-Saharan Africa, where rates of HIV are high.[40][41] Of people without HIV who are infected with tuberculosis, about 5–10% develop active disease during their lifetimes;[16] in contrast, 30% of those coinfected with HIV develop the active disease.[16]