[Epidemiology of infections in very low birth weight infants. Polish Neonatology Network research]

1. prospective record of infections; 2. prevention of nosocomial infections by providing current data about infections, which are significant for making therapeutic decisions.

Recorded infections: early-onset sepsis (congenital), late-onset sepsis (acquired in hospital), necrotising enterocolitis (NEC), pneumonia. Infections were diagnosed and qualified on the basis of definitions of infections based on the National Nosocomial Infections Surveillance (NNIS) criteria, developed by CDC, USA, including modifications of German Neo-KISS programme. Infection control was realised as a part of common research project of "Polish Neonatology Network", appointed by the decision of the Minister of Science and Higher Education no. 669/E-215/BWSN- 0180/2008 dated 20.05.2008 r. The study was conducted by 6 Polish neonatology units, Microbiology Chair of Jagiellonian University Collegium Medicum and Institute of Theoretical and Applied Computer Science. Infants with birth weight lower than 1500 g were qualified for the study.

Between 1.01.2009 and 31.12.2009, 910 patients were registered, i.e. 19.1% of VLBW infants born in that period. The conducted analysis showed significant differences between centres in gestational age, birth weight, hospitalisation, use of invasive procedures, antibiotics and parenteral feeding. Cumulative morbidity rate was 68.5% total. Blood infection (sepsis) was the most commonly observed type of infection: 268 cases - 43.1% of all recorded forms of infection. Pneumonia was diagnosed in 242 cases, 38.8% total. NEC constituted 12.7% studied infections (79 cases). Apart from NEC, the risk of other forms of infection differed between centres. Dominant etiologic factor of all infections were Gram-positive cocci, which constituted 565 isolated microorganisms. Among them coagulase-negative staphylococci (CNS) were the most common (41.7%), while Staphylococcus aureus was fourth most frequent etiologic factor of infections (6.3% total).

1. Introduction of unified definition and criteria for diagnosing infections and the use of morbidity rates enables comparative analysis of epidemiology of infections in neonatal intensive care units. 2. Due to significant differences observed between prophylactic and therapeutic procedures in various units, it is essential to propose Polish recommendations regarding control over etiology of infections and use of invasive procedures, such as intravenous catheters and ventilation. 3. It is essential to undertake action leading to fully rational antibiotic therapy, because overuse of antibiotics leads to bacterial resistance and increases incidence of infections.