1 IV Medical Department with Infectious Diseases and Tropical Medicine, Clinic Favoriten, Kundratstraße 3, 1100, Vienna, Austria. Marianna.traugott@gesundheitsverbund.at.
2 Austrian Reference Centre for Diphtheria, Austrian Agency for Health and Food Safety, Vienna, Austria.
3 Department of Internal Medicine, Cardiology and Nephrology, Hospital of Wiener Neustadt, Wiener Neustadt, Austria.
4 IV Medical Department with Infectious Diseases and Tropical Medicine, Clinic Favoriten, Kundratstraße 3, 1100, Vienna, Austria.
5 Department of Otorhinolaryngology, Hospital of Wiener Neustadt, Wiener Neustadt, Austria.