Despite the enormous progress in the development of treatment options and anti-infective prophylaxis, infectious diseases are still the major problem of modern medicine. There are diseases known to mankind for hundreds of years, and even in ancient times, but there is a concern over new pathogens that have appeared for recent years.

The most spectacular achievements in relation to the treatment of infectious diseases are those developed for effective therapy for chronic hepatitis C virus (HCV) infection, and drugs against hepatitis B virus (HBV) enable control of this infection. Since patients chronically infected with mentioned hepatotropic viruses are the largest group of patients in infectious diseases wards, the ability to impact the infectious process is of considerable practical importance.

This issue of „Postępy Nauk Medycznych” is devoted to discuss a number of current problems related to infectious diseases. Original and review papers are included and the leading theme is chronic viral hepatitis, but some other diseases, that are in the scope of infectious disease specialists interest are disscussed.

Dr Bura with co-authors from Poznań center headed by prof. Mozer-Lisewska discussed the problem of hepatitis E, which by many is seen as quite exotic. As we may learn from the data from Western Europe, the proportion of blood donors with anti-HEV is ten percent, and in some populations may exceed 50%. Modern look at the diagnostic capabilities of HEV infection and its availability can hope to increase detection in our country.

Prof. Łapiński from Białystok discussed the very current issue – threat of new coronaviruses. HVCo-SARS and HVCo-MERS arouse fear of the development of life-threatening diseases on different continents. Spectacular halt of SARS spread was a huge success of epidemiological international forces, but as shown in the current issue of Ebola fever, it is increasingly difficult to create boundaries for the spread of dangerous infections. The author focused his attention on the problem of MERS, which may soon cause another alert for the international community.