Host factors in bacteremic CAP

Background: Bacteremia indicates virulence of pathogen or impaired host defence. Bacteremic CAP are presented by severe clinical course and high mortality rate. Beside virulence of pathogens we wanted to evaluate host factors leading to bacteremia and thus forecasting severe outcome.

Material and Methods: The analysis is retrospective. It includes all pts hospitalised due to bacteremic CAP in 2002. All the data are from patients files.

Results: 18 patients fulfilled inclusion criteria (33% women), average age 69.7 years. 83% had at least 1 accompanying chronic disease, 16% were smokers, 33% ex smokers, 16% were aethylics. All were presented by severe clinical course. 83% had highly elevated body temperature and chills. 50% had unilobar involvement on x-ray, 39% pleural effusion. CRP was very high in 22%, WBC count very high in 28%. In hemoculture we isolated S.pneumoniae in 72%, E. coli in 17%, B. cepacia in 0.5% and MRSA in 0.5%. All S. pneumoniae strains were sensitive to penicillin. 5 patients died (28%).

Conclusion: Most important factors leading to invasive bacterial infection are comorbidity and impaired host defence mechanisms. Smoking impaires local host defence, aethylismus sistemic one. Mortality in bacteremic CAP is high, determined mostly by numerous comorbidities and virulent microorganisms. S. pneumonia remains the most common pathogen causing bacteremia in CAP patients. In our country the frequency of PRSP strains remains low.