Molecular epidemiology as an effective tool in the surveillance of infections in the neonatal intensive care unit.

OBJECTIVES

nosocomial infections result in considerable morbidity and mortality in Neonatal Intensive Care Units (NICUs). The aim of this study was to investigate the usefulness of the molecular epidemiology approach in the surveillance and control of infections in the NICU.

METHODS

a 1-year prospective surveillance of nosocomial infections in a NICU was performed using traditional epidemiological methods as well as molecular typing of micro-organisms.

RESULTS

the nosocomial infection rate among the 343 newborns was 24.8%. The risk of infection was associated with low birth weight, prolonged length of stay, empiric antibiotic treatment and nasopharyngeal colonization. Four pathogens (Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE) and methicillin-sensitive Staphylococcus aureus (MSSA) were responsible for more than 80% of the infections. Extended-spectrum beta-lactamase-producing (ESBL) K. pneumoniae and MRSA infections constituted outbreaks caused by a single clone, whereas MRSE and MSSA infections did not represent outbreaks but rather a series of sporadic infections caused by different strains.

CONCLUSIONS

molecular epidemiology techniques are powerful tools that can elucidate modes of spread and reservoirs of infection in the NICU and identify effective measures to control epidemic or endemic situations.