Update on tuberculosis epidemiology

Abstract number: S342

Hoffner S.

When tuberculosis epidemiology is seen in a global perspective, and the Millennium Development Goals are considered, it is clear that two regions of the world, Africa and Europe, are severely behind in the control of the disease. In Africa, especially sub-Saharan Africa, the TB problem is closely related to the endemic HIV/AIDS situation. In Europe, especially the eastern part and in parts of the former Soviet Union, the main obstacle to an effective TB control is related to drug resistant forms of M. tuberculosis. The prevalence of the most severe forms of resistance, MDR- and XDR-TB, is so high that it makes control efforts both extremely complicated and very expensive. Unfortunately, increasing levels of drug resistant TB are today also seen in many African countries, and HIV infection is spreading in Eastern Europe.

During the last ten-year period new tools, based on molecular fingerprinting of M. tuberculosis strains, have been increasingly adapted to study TB transmission. With such molecular methods to characterise clinical isolates of M. tuberculosis it is now possible to study the spread of individual strains of the bacteria in detail. The laboratory tools used, RFLP, MIRU/VNTR, spoligotyping and others, will be presented and their use exemplified. How molecular epidemiology contributed to the detection and characterisation of a major outbreak of drug resistant TB in the Stockholm area will be discussed.

Molecular characterisation of clinical isolates from different parts of the world has led to an increased recognition of the differences between different families of M. tuberculosis strains. To further describe and understand the role of these differences in the clinical field as well as for TB epidemiology is an ongoing and interesting field of research. An increased understanding of how TB is transmitted will hopefully help in the efforts to control this global health threat both on the local level and in a global perspective.