The principal aim of this review is to shed light on practical issues of etiology and management of pneumonias with special respect to the most recent international practice guidelines and data on antimicrobial resistance in Estonia as well as in Europe. The etiology and resistance patterns are substantially affected by host-related modifying factors. Apart from Streptococcus pneumoniae as the leading pathogen, Staphylococcus aureus and gram-negative bacilli also play a major role. Clinical investigations, as well as management need to be carried out according to severity of pneumonia. In addition to routine sputum analyses, determination of bacterial antigens in the urine is usually of benefit. Nevertheless, modern methods targeted to detection of pathogen-specific DNA are preferred in determining the typical pathogens but are also favored in the diagnostics of viral and other atypical pathogens.
The initial therapy of microbial pneumonias is empiric. In non-severe cases, treatment with antibiotics with an as narrow antibacterial spectrum as possible is indicated. To treat severe pneumonia, use of antibacterials with a broad spectrum of action or a combination of two or more drugs is considered reasonable. In the presence of modifying or risk factors 2nd-generation cephalosporins or beta-lactam antibiotics combined with beta-lactamase inhibitors are indicated. In Estonia, the penicillin and macrolide resistance of pneumococci is less than 5%. To prevent development of resistance higher than this, a proper policy for usage of antibiotics needs to be implemented with an establishment of infection control services in major hospitals.