Nosocomial or hospital acquired infections threaten the survival and neurodevelopmental outcomes of infants admitted to the neonatal intensive care unit, and increase cost of care. Premature infants are particularly vulnerable since they often undergo invasive procedures and are dependent on central catheters to deliver nutrition and on ventilators for respiratory support. Prevention of nosocomial infection is a critical patient safety imperative, and invariably requires a multidisciplinary approach. There are no short cuts. Hand hygiene before and after patient contact is the most important measure, and yet, compliance with this simple measure can be unsatisfactory. Alcohol based hand sanitizer is effective against many microorganisms and is efficient, compared to plain or antiseptic containing soaps. The use of maternal breast milk is another inexpensive and simple measure to reduce infection rates. Efforts to replicate the anti-infectious properties of maternal breast milk by the use of probiotics, prebiotics, and synbiotics have met with variable success, and there are ongoing trials of lactoferrin, an iron binding whey protein present in large quantities in colostrum. Attempts to boost the immunoglobulin levels of preterm infants with exogenous immunoglobulins have not been shown to reduce nosocomial infections significantly. Over the last decade, improvements in the incidence of catheter-related infections have been achieved, with meticulous attention to every detail from insertion to maintenance, with some centers reporting zero rates for such infections. Other nosocomial infections like ventilator acquired pneumonia and staphylococcus aureus infection remain problematic, and outbreaks with multidrug resistant organisms continue to have disastrous consequences. Management of infections is based on the profile of microorganisms in the neonatal unit and community and targeted therapy is required to control the disease without leading to the development of more resistant strains.
Background
Advances in neonatal care have lead to the increasing survival of smaller and sicker infants, but nosocomial infections [NI], also known as health care associated or hospital acquired infections continue to be a serious problem. Late-onset sepsis [LOS], or sepsis acquired after 72 h of life, with the exception of Group B streptococcal or Herpes simplex virus infection, is usually hospital acquired, particularly in infants who are hospitalized from birth. These infections are associated with increased mortality rates, immediate and long term morbidity, prolonged hospital stay and increased cost of care [1–3]. Efforts to eradicate neonatal NI have had limited success in some areas, but many remain intransigent, and outbreaks with multi – drug resistant organisms [MDRO] continue to occur in neonatal intensive care units [NICUs] worldwide.
Risk of NI in preterm, late preterm and term infants
Prematurity is the most important risk factor for NI. In the United States, surveillance data over almost 2 decades from the National Institute of Child Health and Human Development [NICHD] Neonatal Network show that 20–25% of very low birth weight [VLBW, birth weight ≤ 1500 g] infants who survived beyond 3 days were found to have one or more episodes of blood culture proven sepsis, with the majority being caused by gram-positive organisms, predominantly coagulase-negative staphylococci [CONS] [Table 1] [1–3]. The rate of infections was inversely related to birth weight and gestational age, with 50% of the infections occurring in infants born at 7 days, lack of enteral feeding and presence of a central catheter have all been associated with increased risk of invasive candidiasis, and in extremely low birth weight infants [< 1000 g], invasive candidiasis has been associated with 73% mortality or neurodevelopmetal impairment [47]. Fungal infection accounted for 9% of cases of LOS in VLBW infants in 1996 [1], but more recent studies indicate that invasive candidiasis has decreased in NICUs in the United States since 1997, probably secondary to the widespread use of fluconazole prophylaxis and decreased use of broad spectrum antibacterial antibiotics [48]. In a study of data from 709,325 infants at 322 NICUS managed by the Pediatrix Medical Group from 1997 to 2010, the annual incidence of invasive candidiasis among infants with a birth weight of 750–999 g decreased from 24.2 to 11.6 episodes per 1000 patients, and from 82.7 to 23.8 episodes per 1000 patients among infants with a birth weight