Methicillin-resistant Staphylococcus aureus colonization and its association with infection among infants hospitalized in neonatal intensive care units.
OBJECTIVE
We conducted this study to assess the rate of methicillin-resistant Staphylococcus aureus colonization and its association with infection among infants hospitalized in methicillin-resistant S aureus-endemic NICUs.


METHODS
Between March 2003 and February 2004, surveillance culture specimens from the nares, postauricular areas, axillae, and umbilicus of infants admitted to the NICUs at a children's hospital in Taiwan were obtained weekly for the detection of methicillin-resistant S aureus. All colonized and clinical isolates from each study infant with methicillin-resistant S aureus infection were genotyped with pulsed-field gel electrophoresis, with Sma1 digestion, and compared.


RESULTS
A total of 783 infants were included in this study. Methicillin-resistant S aureus colonization was detected for 323 infants during their NICU stays, with detection with the first 2 samples for 89%. Nares and umbilicus were the 2 most common sites of initial colonization. Methicillin-resistant S aureus colonization was associated significantly with premature birth (< or = 28 weeks) and low birth weight (< or = 1500 g), and infants with colonization had a significantly higher rate of methicillin-resistant S aureus infection, compared with those without colonization (26% vs 2%). Methicillin-resistant S aureus colonization was noted for 84 of 92 infants with methicillin-resistant S aureus infections. Of the 68 episodes with previous colonization and isolates available for genotyping analysis, colonized and clinical isolates were indistinguishable in 63 episodes, highly related in 2 episodes, and distinct in 3 episodes.


CONCLUSIONS
More than 40% of the hospitalized infants were colonized with methicillin-resistant S aureus during their stay in methicillin-resistant S aureus-endemic NICUs; this was associated significantly with methicillin-resistant S aureus infection. Most infants with methicillin-resistant S aureus infections had previous colonization with an indistinguishable strain.
Huang
Yhu-Chering
YC
Division of Pediatric Infectious Diseases, Chang Gung Children's Hospital, 5 Fu-Shin St, Kweishan, Taoyuan, Taiwan. ychuang@adm.cgmh.org.tw
Chou
Yi-Hong
YH
Su
Lin-Hui
LH
Lien
Rey-In
RI
Lin
Tzou-Yien
TY
D001365:Axilla / Q000382:microbiology; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology; D015373:Bacterial Typing Techniques; D001724:Birth Weight; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D004431:Ear, External / Q000382:microbiology; D005260:Female; D005865:Gestational Age; D006776:Hospitals, Pediatric / Q000706:statistics & numerical data; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000453:epidemiology* / Q000382:microbiology; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data*; D008297:Male; D016106:Methicillin Resistance; D009666:Nose / Q000382:microbiology; D010356:Patient Isolation; D012867:Skin / Q000382:microbiology*; D013183:Sputum / Q000382:microbiology; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D013624:Taiwan / Q000453:epidemiology; D014472:Umbilicus / Q000382:microbiology
D004269:DNA, Bacterial