Staphylococcus aureus infections in Australasian neonatal nurseries

Abstract

Objective: To study the incidence and outcome of systemic infections with methicillin sensitive (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) infections in Australasian neonatal nurseries. Methods: Prospective longitudinal study of systemic infections (clinical sepsis plus positive cultures of blood and/or cerebrospinal fluid) in 17 Australasian neonatal nurseries. Results: The incidence of early onset sepsis with S aureus, mainly MSSA, was 19 cases per 244 718 live births or 0.08 per 1000. From 1992 to 1994, MRSA infections caused only 8% of staphylococcal infections. From 1995 to 1998, there was an outbreak of MRSA infection, in two Melbourne hospitals. The outbreak resolved, after the use of topical mupirocin and improved handwashing. Babies with MRSA sepsis were significantly smaller than babies with MSSA sepsis (mean birth weight 1093 v 1617 g) and more preterm (mean gestation 27.5 v 30.3 weeks). The mortality of MRSA sepsis was 24.6% compared with 9.9% for MSSA infections. The mortality of early onset MSSA sepsis, however, was 39% (seven of 18) compared with 7.3% of late onset MSSA infection presenting more than two days after birth. Conclusions: S aureus is a rare but important cause of early onset sepsis. Late onset MRSA infections carried a higher mortality than late onset MSSA infections, but babies with early onset MSSA sepsis had a particularly high mortality.

Predictors of Mortality in Staphylococcus aureus Bacteremia

“…The impact of methicillin resistance is unclear, with MRSA mortality rates being significantly higher than those associated with MSSA episodes (24.6%, versus 9.9% for MSSA; P Ͻ 0.001) in an Australian and New Zealand NICU study by Isaacs et al (115). However, MRSA episodes occurred in infants who were more premature and of lower birth weights.…”

“…Differences in these results are probably related to study design, patient populations, baseline institutional expertise in SAB management, and adherence to ID advice. fied risk factors for mortality include low birth weight (Ͻ1,000 g; P Ͻ 0.01) (58) and age at the onset of infection, with early-onset MSSA sepsis (Յ48 h of age) being associated with a significantly higher mortality rate than that associated with late-onset MSSA infections (39% versus 7.3%; P Ͻ 0.01) (115).…”

New Threats from an Old Foe: Methicillin-Resistant <b><i>Staphylococcus aureus</i></b> Infections in Neonates

“…Sepsis, especially late-onset sepsis, is currently the most common manifestation of invasive MRSA infections, with one third of cases presenting as MRSA sepsis [2, 25]. However, though sporadically, early-onset sepsis caused by MRSA has been also reported in industrialized countries [23, 25]. Data from developing countries are lacking.…”

“…Other risk factors for MRSA infections include prolonged hospitalization, overcrowding and understaffing in neonatal wards, long-term use of respiratory support, intravascular catheters, antibiotics, and total parenteral nutrition, as well as surgical procedures [6, 18, 19]. The clinical manifestation of MRSA infections may range from mild focal infections, such as conjunctivitis and skin and soft tissue infections, to more severe forms like toxic shock syndrome [24] and even invasive infections such as sepsis, necrotizing pneumonia, meningitis, endocarditis, osteomyelitis, liver abscesses, and urinary tract infections [2, 18, 23, 25-27]. Sepsis, especially late-onset sepsis, is currently the most common manifestation of invasive MRSA infections, with one third of cases presenting as MRSA sepsis [2, 25].…”

“…The clinical manifestation of MRSA infections may range from mild focal infections, such as conjunctivitis and skin and soft tissue infections, to more severe forms like toxic shock syndrome [24] and even invasive infections such as sepsis, necrotizing pneumonia, meningitis, endocarditis, osteomyelitis, liver abscesses, and urinary tract infections [2, 18, 23, 25-27]. Sepsis, especially late-onset sepsis, is currently the most common manifestation of invasive MRSA infections, with one third of cases presenting as MRSA sepsis [2, 25]. However, though sporadically, early-onset sepsis caused by MRSA has been also reported in industrialized countries [23, 25].…”