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Biosensor for Detection of Antibiotic Resistant Staphylococcus Bacteria
Published on: May 8, 2013
[Identification of risk times for dissemination of methicillin-resistant Staphylococcus aureus in an intensive care
Francisco Alvarez-Lerma1, Montserrat Gasulla Guillermo, Victoria Abad Peruga
1Universidad Autónoma de Barcelona, UDUM, Barcelona, Spain. falvarez@imas.imim.es
Background And Objective:
The dissemination of methicillin-resistant Staphylococcus aureus (MRSA) in patients admitted to an Intensive Care Unit (ICU) depends, among other reasons, on the time interval between obtention of the first positive sample and the establishment of measures for contact isolation. The objective of this study was to identify the risk intervals for the spread of MRSA in ICU patients and to assess the relationship between these periods and the development of new cases of MRSA acquired in the ICU.
Material And Method:
Observational and prospective study, which was carried out in a 18-bed polyvalent ICU during a 49-month period (October 1998-October 2002). The exposure risk period was defined as the time elapsed between obtention of the first positive sample and contact isolation of the index case, and the window period as the time elapsed between recovery of the last negative sample to the first positive sample. Infection sources of MRSA were classified into community-acquired and hospital-acquired (nosocomial extra-ICU and nosocomial intra-ICU infections).
Results:
MRSA was isolated in 69 (2.73%) of 2,531 patients admitted to the ICU during the study period and in all patients measures of contact isolation were indicated. Community-acquired MRSA was diagnosed in 9 (13%) cases, nosocomial intra-ICU in 29 (42%), and nosocomial extra-ICU in 31 (44.9%). The mean duration of the exposure risk period was 3.1 (SD 2.2) (median 3, range 0-9) days and the window period 2.9 (SD 4.6) (median 1, range 0-28) days. In 18 of the 29 cases of intra-ICU-acquired MRSA (62.1%; 95% CI, 42.3-79.3), the infection was acquired within the exposure risk and/or window periods of other patients with MRSA.
Conclusions:
The exposure risk periods and the window periods showed a strong relationship between detection of new cases of intra-ICU colonization and/or infection by MRSA.
Insights
Identifying critical time intervals for methicillin-resistant Staphylococcus aureus (MRSA) spread in Intensive Care Units (ICUs) is crucial. Delays in contact isolation after positive MRSA samples significantly increase the risk of new ICU-acquired infections.
Area of Science:
- Infectious Diseases
- Critical Care Medicine
- Epidemiology
Background:
- Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant threat in Intensive Care Units (ICUs).
- The timing of contact isolation after detecting MRSA influences its dissemination.
- Understanding transmission dynamics is key to preventing healthcare-associated infections.
Purpose of the Study:
- To identify critical risk intervals for MRSA spread among ICU patients.
- To evaluate the relationship between these periods and the incidence of new MRSA cases acquired within the ICU.
Main Methods:
- An observational, prospective study was conducted in an 18-bed polyvalent ICU over 49 months.
- Defined 'exposure risk period' (time from first positive sample to isolation) and 'window period' (time from last negative to first positive sample).
- Classified MRSA infection sources as community-acquired or hospital-acquired (intra-ICU or extra-ICU).
Main Results:
- MRSA was detected in 2.73% of 2,531 ICU patients.
- The mean exposure risk period was 3.1 days, and the window period was 2.9 days.
- Over 62% of intra-ICU acquired MRSA cases occurred during the exposure risk and/or window periods of other patients.
Conclusions:
- Exposure risk and window periods are strongly associated with the detection of new MRSA colonization and/or infection within the ICU.
- Prompt isolation following MRSA detection is critical to prevent further transmission.
- These findings highlight the importance of timely interventions to control MRSA spread in ICUs.
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