Non-Multidrug-Resistant, Methicillin-Resistant Staphylococcus aureus in a Neonatal Unit

Background: in the last decade, non-multiresistant methicillin-resistant Staphylococcus aureus (NM-MRSA) has been described as an important agent in bloodstream infections in our hospital.Methods: This prospective cohort study, conducted from February 2009 through January 2010 in the neonatal unit, evaluated 403 newborns (NB), their 382 mothers and 148 health care workers (HCW).Results: Approximately 217 NB (54%), 187 mothers (48%) and 87 HCW (59%) were colonized by S. aureus (SA). MRSA colonization was greater among NB (15%) than mothers (4.7%) and HCW (3.4%). Although mother-to-NB transmission occurred, in most cases mothers were not responsible for NB colonization. There were 2 predominant PFGE patterns among the NB and some mothers and HCW became colonized by them. Factors significantly associated with MRSA carriage by NB were lower level of maternal schooling (risk factor: odds ratio: 2.99; 95% confidence interval: 1.10-8.07) and maternal rhinosinusitis (protective factor: odds ratio: 0.33; 95% confidence interval: 0.12-0.88). Among NB who remained hospitalized for more than 72 hours, breast feeding was protective (odds ratio: 0.22; 95% confidence interval: 0.05-0.98). All the isolates were NM-MRSA, carried few virulence factors and SCCmec types IVa and type IVd predominated.Conclusions: Although there were no cases of infection, nosocomial transmission of MRSA clearly occurred in the neonatal unit, and this highlights the need for infection control practices such as hand hygiene to prevent cross-dissemination. Other healthcare practices, which are very basic but also ample in scope, may play a role, such as general education of women and breast feeding.Fundacao de Auxilio a Pesquisa do Estado de São PauloUniv São Paulo, Hosp Clin, Dept Infect Dis, São Paulo, BrazilUniv São Paulo, Hosp Clin, LIM 54, São Paulo, BrazilUniv São Paulo, Hosp Clin, Dept Infect Control, São Paulo, BrazilUniv São Paulo, Dept Pediat, São Paulo, BrazilUniv São Paulo, Fac Publ Hlth, São Paulo, BrazilUniv São Paulo, Dept Obstet, São Paulo, BrazilUniv São Paulo, Inst Med Trop São Paulo, São Paulo, BrazilFundacao de Auxilio a Pesquisa do Estado de São Paulo: 2009/08206-1Fundacao de Auxilio a Pesquisa do Estado de São Paulo: 2009/07746-2Fundacao de Auxilio a Pesquisa do Estado de São Paulo: 2009/10595-2Fundacao de Auxilio a Pesquisa do Estado de São Paulo: 2009/19829-7Web of Scienc