2007 A retrospective case-control study of the risk factors for acquisition of Penicillin-Resistant Streptococcus pneumoniae
Dr Chow Chee Wung
Department of Medicine, Caritas Medical Center
Background
Community-acquired pneumonia (CAP) remains a common and potentially life-threatening disease. Streptococcus pneumoniae is the most common bacterial cause of CAP but the resistance of Streptococcus pneumoniae to penicillin and other antimicrobials is on the rising trend. Treatment failure associated with antibiotic-resistant pneumococci has been reported for patients with otitis media and meningitis, although the clinical significance of antimicrobial resistance for patients with pneumococcal pneumonia remains controversial. A retrospective multi-centre study was conducted in the Kowloon West Cluster in Hong Kong involving 3 acute hospitals in order to get a better understanding of the epidemiological and clinical aspects of penicillin-resistant Streptococcus pneumoniae (PRSP).
Objectives
To identify the possible risk factors for the acquisition of PRSP by patients and the clinical relevance.
Methods
A retrospective case-control study which tried to compare the frequency of exposure and the clinical features of case patients so as to identify those potential risk factors associated with either infection or colonization with PRSP.
Results
There were about 3,851 S pneumoniae isolated from respiratory specimens in adult patients between the year 2000 and 2005. Only 1.3% of cases were noted to have penicillin resistant with MIC 2µg/mL. The potential risk factors identified in the univariate analysis include recent hospitalization, multiple hospitalization, hospital origin of infection/colonization, exposure to beta-lactam antibiotics within 6 weeks or 12 months prior to current admission, exposures to macrolides antibiotics within 12 months prior to current admission, use of 2 or more and use of 3 or more courses of beta-lactam antibiotics within 1 year prior to current admission. However, multivariate analysis showed only 2 factors were independently associated with PRSP infection / colonization which include exposures to beta-lactam antibiotics within 6 weeks prior to current admission and hospital origin of infection/colonization. The acquisition of PRSP did not significantly affect the clinical outcome of patients.
Conclusion
The judicious use of antibiotics is of utmost importance in preventing the spread of multi-resistant pneumococci.
