<s>[INST] What is the status of TB transmission in the world? [/INST] Despite the above bleak statistics, until recently, TB prevalence and mortality rates were
decreasing almost everywhere. Estimates of TB infection rates continue to decline in
everywhere, except Africa, where they are rising steadily. This is explained by the
insufficient capacity of health systems to deal with the detection and treatment of
tuberculosis. It is also explained by the spread of HIV. As people with HIV infection get
ill, they become particularly susceptible to TB. Since 1990, therefore, TB infection rates
have increased by a factor of four in countries that are heavily affected by HIV.  Source: UNAIDS. Link: https://data.unaids.org/pub/factsheet/2006/tb_hiv_qa.pdf. Field: Lung Disease. Disease: Tuberculosis </s>