Nasal carriage of Staphylococcus aureus and cross-contamination in a surgical intensive care unit: efficacy of mupirocin ointment.
A six month prospective study was carried out in a surgical intensive care unit (SICU) of a university hospital to assess the incidence and routes of exogenous colonization by Staphylococcus aureus. A total of 157 patients were included in the study. One thousand one hundred and eleven specimens (nasal, surgical wound swabs, tracheal secretions obtained on admission and once a week thereafter, and all clinical specimens) were collected over a four month period from patients without nasal decontamination (A). They were compared with 729 specimens collected over a two month period from patients treated with nasal mupirocin ointment (B). All S. aureus strains were typed by restriction fragment length polymorphism (RFLP) pulsed-field gel electrophoresis after SmaI macrorestriction. The nasal colonization rates on admission were 25.5 and 32.7% in groups A and B, respectively. Thirty-one untreated patients (31.3%) and three patients (5.1%) treated with nasal ointment, acquired the nasal S. aureus in the SICU (P = 0.00027). Nasal carriers were more frequently colonized in the bronchopulmonary tract (Bp) and surgical wound (Sw) (62%) than patients who were not nasal carriers (14%) (P < 0.00001). The patterns were identical for nasal, Bp and Sw strains from the same patient. RFLP analysis characterized seven epidemic strains of methicillin-resistant S. aureus (MRSA) which colonized 60% of group A and 9% of group B patients (P < 0.00001). The bronchopulmonary tract infection rate was reduced in group B (P = 0.032). In conclusion, in an SICU, nasal carriage of S. aureus appeared to be the source of endogenous and cross-colonization. The use of nasal mupirocin ointment reduced the incidence of Bp and Sw colonization, as well as the MRSA infection rate.
Talon
D
D
Laboratoire de Bactériologie-Hygiène, Faculté de Médecine, Hôpital Jean Minjoz, Besançon, France.
Rouget
C
C
Cailleaux
V
V
Bailly
P
P
Thouverez
M
M
Barale
F
F
Michel-Briand
Y
Y
D000281:Administration, Intranasal; D015373:Bacterial Typing Techniques; D002353:Carrier State / Q000382:microbiology*; D015169:Colony Count, Microbial; D003428:Cross Infection / Q000382:microbiology / Q000517:prevention & control*; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D016106:Methicillin Resistance; D016712:Mupirocin / Q000494:pharmacology*; D009297:Nasal Mucosa / Q000382:microbiology*; D009824:Ointments; D011446:Prospective Studies; D013203:Staphylococcal Infections / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000302:isolation & purification*
D009824:Ointments; D016712:Mupirocin