Chapter 4 The dual epidemic: HIV/Aids and tuberculosis (TB) H IV/Aids and TB are the greatest killers worldwide among infectious agents.1 The HIV/Aids epidemic and the concomitant increase in the TB epidemic have been called the dual epidemic or intersecting epidemic, not only because of their chronological and geographic coincidence but mainly because the two diseases and epidemics have a strong negative infuence on each other. For both diseases the highest prevalence is found in low‑income countries. On a world map, regions with high HIV incidence and prevalence match largely with regions of high TB incidence and prevalence. About one third of the 34 million people living with HIV infection are co‑infected with TB and they are about 30 times more likely to fall ill with TB than people with an intact immune system. More than half of all Aids patients manifest TB disease and TB is the most common serious opportunistic infection in HIV patients. Almost 25% of deaths among people with HIV are due to TB.2 In addition, there is a newly emerged problem of the increasing drug resist‑ ance of TB, and the primary cause is inappropriate TB treatment. In eastern European countries more than 10% of newly infected people are infected with drug‑resistant bacilli strains and this rate is of course much higher in previously treated and relapsed patients. The former DOTS strategy (directly observed treatment short course) of the World Health Organization (WHO) had to be upgraded to “DOTS plus” due to the need for additional and more expensive diagnostic equipment along with the extended second‑line treatment with more side‑efects.3 1. WHO Fact sheets (October 2012). 2. Ibid. 3. Ibid. Page 63