Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, is one of the most common and dangerous infectious diseases worldwide. More than a third of the world’s population has been infected with tuberculosis bacteria, according to estimations by the World Health Organization WHO (on tuberculosis in Europe: http://ecdc.europa.eu/en/healthtopics/Tuberculosis/world-tb-day/Pages/2017-unite-to-end-TB.aspx). Five out of 100 people infected with tuberculosis bacteria will suffer a tuberculosis outbreak within two years; another five will develop tuberculosis symptoms over the course of the following decades.
The disease is usually transmitted via microscopically small droplets, so-called aerosols, shed by coughing, sneezing, singing or speaking. However, contact over several hours in closed, badly aired rooms would be necessary to transfer the bacteria. Short periods of contact, especially outdoors, do not pose any relevant risks.
Situation in Austria
The cases of new infections per year in Austria dropped from 1,007 cases in 2005 to 583 cases in 2015, the lowest number ever recorded in Austria. Notification data from 2016 show an increase to a total of 644 cases in the last year. Though, this number is also affected by the higher migration figures, partly from high-incidence countries, over the past two years. The incidence of tuberculosis in Austria remains low at 7.3/100,000 inhabitants (215: 6.7/100,000 inhabitants). Fourteen cases of multi-drug-resistant tuberculosis (2015: 11 cases) and two cases of extremely drug-resistant tuberculosis (2015: 1 case) were diagnosed in 2016.