Epidemiology of nosocomial bloodstream infections in Estonia.

A prospective multicentre hospital-wide surveillance study was performed to investigate nosocomial bloodstream infections (BSIs) and to promote BSI surveillance in Estonia in 2004-2005. All patients from the acute care departments of two referral centres and one central hospital were included. A total of 549 episodes of BSI occurred in 507 patients (0.6 cases per 1000 patient-days). Of those, 55% occurred in intensive care units and 47% were catheter-associated infections. Of BSI cases, 24% occurred in patients with haematological malignancy. The in-hospital case-fatality rate was 31%. Of causative micro-organisms, 315 (53%) were Gram-positive aerobes, 232 (39%) were Gram-negative aerobes and 35 (6%) were fungi. Anaerobic bacteria accounted for 2%. The most common pathogens were coagulase-negative staphylococci (26%), Enterobacteriaceae (24%), enterococci (13%) and pseudomonas (10%). Eight percent of BSI were polymicrobial. Seven percent of Staphylococcus aureus isolates were meticillin resistant. Of pseudomonas isolates, 19%, 25%, 30% and 44% were resistant to ceftazidime, meropenem, piperacillin/tazobactam and imipenem, respectively. The incidence of BSI did not differ significantly from other reported studies. With the exception of relatively high antimicrobial resistance among pseudomonas, the overall resistance patterns of Estonian nosocomial bloodstream pathogens were similar to those seen in Nordic countries and lower than in Central and Southern Europe. This study contributes to the development and implementation of surveillance in Estonian hospitals.