title: Staphylococcus aureus outbreak in the intensive care unit of the largest public hospital in Quito, Ecuador.
abstract: Staphylococcus aureus is a frequent cause of nosocomial pneumonia and bacteremia worldwide. Classical and molecular epidemiology approaches were used to study a S. aureus outbreak in the intensive care unit (ICU) of one of the largest public hospitals in Quito. Staphylococcus aureus isolates from 17 patients and 19 potential carriers from the staff were collected from March 2007 to February 2008 and analyzed by pulsed-field gel electrophoresis (PFGE) to determine their clonal relationships. During this period the hospital reported 16 cases of hospital-acquired staphylococcal pneumonia and an apparent outbreak occurred from June to September 2007. DNA from these isolates formed six different PFGE patterns: four clonal groups, and two groups of clonally related isolates. Molecular typing failed to identify any staphylococcal reservoir among staff members. The current study suggested that a staphylococcal outbreak that occurred in the summer of 2007 was caused by different bacterial clones, although some clones were shared by two patients. Historical analysis of the staphylococcal infections in the ICU showed a higher incidence during the summer months, which coincided with the programmed personnel shift. This observation suggests that outbreaks might be produced by the introduction of improperly trained personnel.
authors.affiliation: Institute of Microbiology, College of Biological and Environmental Sciences, University of San Francisco de Quito, Quito, Ecuador.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Cardenas
authors.affiliation: Carlos Andrade Marín Hospital, Quito, Ecuador.
authors.forename: Marta
authors.initials: M
authors.lastname: Alarcón
authors.affiliation: Carlos Andrade Marín Hospital, Quito, Ecuador.
authors.forename: Inés
authors.initials: I
authors.lastname: Narvaez
authors.affiliation: Carlos Andrade Marín Hospital, Quito, Ecuador.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Salazar
authors.affiliation: Carlos Andrade Marín Hospital, Quito, Ecuador.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Falconí
authors.affiliation: Institute of Microbiology, College of Biological and Environmental Sciences, University of San Francisco de Quito, Quito, Ecuador.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Espinel
authors.affiliation: Institute of Microbiology, College of Biological and Environmental Sciences, University of San Francisco de Quito, Quito, Ecuador.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Trueba
mesh_terms: D015373:Bacterial Typing Techniques; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D004196:Disease Outbreaks; D004484:Ecuador / Q000453:epidemiology; D005260:Female; D006779:Hospitals, Public; D006801:Humans; D007362:Intensive Care Units; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*