Epidemiological and clinical aspects of mycobacterial infections.

The incidence of tuberculosis in the developed countries has recently started to rise again due to increased migration, a higher rate of direct transmission of Mycobacterium tuberculosis, and co-infection with HIV. The impact of the latter on the pathogenesis and presentation of tuberculosis is summarised. Important measures to prevent the further spread of tuberculosis include rapid diagnosis, prompt isolation of infectious patients, adequate control of treatment compliance, as well as surveillance of local resistance patterns. Disease due to the Mycobacterium avium complex is more frequent among HIV-infected patients in Central Europe than tuberculosis, and its development in the presence of immune deficiency seems to be mainly the result of a new infection with this ubiquitous microorganism rather than the reactivation of a previously acquired infection. It has a significant impact on mortality. The diagnosis of Mycobacterium avium complex infection requires a high degree of conjecture because most of the symptoms are non-specific, such as fever, night sweats, weight loss and anaemia. Promptly initiated treatment significantly prolongs the survival time of those affected by comparison with untreated patients.