Results
Study Population
A total of 1015 neonates were admitted to the NICU during the study period and included in the analysis. In the first period 510 infants were hospitalized and 505 in the second, for a total of 16 163 patient-days (8567 and 7596 patient-days for, respectively, the first and the second period). Table 2 shows demographic data and perinatal risk factors for HAI in the two groups.
Main Outcome (MRSA Infection Incidence)
Thirty MRSA infections occurred in the first period and five in the second. All infants had MRSA isolated from blood culture; 14 infants developed clinical sepsis, 12 pneumonia, 4 meningitis, 3 endocarditis proven by echocardiography, 1 bone and joint infection, and 1 necrotizing enterocolitis. Three infants died.
MRSA infection incidence was significantly higher in the first period with 3.5 cases per 1000 patient-days (95% confidence interval [CI]: 2.4–5.0) versus the second, with 0.7 cases per 1000 patient-days (95% CI: 0.3–1.6) (p=0.0005).
The piecewise Poisson regression analysis adjusted for confounding variables showed a significant decrease in the MRSA infection rate after the implementation of the outbreak management strategy (p=0.046) (Figure 2).
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Figure 2.
Rates of Methicillin-resistantStaphylococcus aureus(MRSA) infections before and after the outbreak management strategy implemented at month 19. On the x axis, time (months); on the y axis, rate of MRSA infection (number for 1000 patient-days).
Secondary Outcomes
With the exception of other Gram positive pathogens, the rate of laboratory-confirmed bloodstream infections was significantly lower during the second period (data shown in Table 3).
Other Quality Indicators
The rate of MRSA colonization declined significantly over the second period (p=0.001) (Figure 3).
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Figure 3.
Decline of Methicillin-resistantStaphylococcus aureus(MRSA) colonization rate over the second period of the study. On the x axis, time (months); on the y axis, rate of MRSA colonization (number for 1000 patient-days).
The rate of retained actions implementation was 93% as only two retained actions were not implemented: the case–control study to identify risk factors for MRSA infections and the MRSA clinical isolates genotyping (only performed on certain patients). Over the second period the compliance rate for hand-hygiene and insertion/care of CVL was 95.9% and 62%, for a total of 1722 and 75 observations, respectively.
The hydroalcoholic solution consumption calculated on period basis was 137.61 and 227.06 L/patient-days in the first and the second period respectively.