Risk factors for hospital-acquired infections in the neonatal intensive care unit.

Infants in the neonatal intensive care unit (NICU) have many risk factors for infection. Compared with older children and adults, infants, particularly premature infants, are relatively immunocompromised. Patients in the NICU have intrinsic risk factors for infections due to immunological "deficiencies" or inadequate development of mechanical barriers such as skin and gastrointestinal tract mucosa. Like other ICU populations, NICU patients have extrinsic risk factors for infection such as prolonged hospitalization, invasive procedures, instrumentation, medical treatments and concomitant medical conditions. Compared with healthy full-term infants, patients in the NICU develop abnormal flora, which is generally acquired in the NICU from patient-to-patient transmission via hand carriage of healthcare workers. This flora is frequently multidrug-resistant as it has developed under the selective pressure of antibiotics and can cause invasive disease. An understanding of the risk factors that are associated with hospital-acquired infections is essential to design preventive strategies.