Surveillance of pharyngeal colonization: detection and control of serious bacterial illness in low birth weight infants.
Routine surveillance for bacterial colonization has been used for the past three decades as a tool for the prediction of nosocomial infection in low birth weight infants; however, its usefulness has never been proven. A prospective cohort study was conducted to examine the utility of surveillance for pharyngeal colonization in detection and control of serious bacterial illness in low birth weight infants. One hundred fifty-four infants who weighed less than 1750 g and who were admitted to the Neonatal Intensive Care Unit were enrolled and followed for a total of 5620 infant-days. Pharyngeal cultures were collected at the time of enrollment and then weekly. All infants had bacterial pharyngeal colonization by the third day of life. Coagulase-negative staphylococci were the most common organisms cultured from the pharynx, followed by viridans streptococci and Staphylococcus aureus. More than 90% of the pharyngeal cultures grew multiple isolates. Gram-positive organisms, particularly coagulase-negative staphylococci, were the most prevalent organism recovered from blood and cerebrospinal fluid cultures. Fifty-two episodes of bacteremia and 6 episodes of cerebrospinal fluid infection occurred in 42 infants. Among infants with viridans streptococci in pharyngeal cultures, the subsequent risk of serious bacterial illness was significantly reduced (odds ratio = 0.16). However, pharyngeal cultures were poor predictors of the causative organism in an episode of serious bacterial illness. Pharyngeal and blood/cerebrospinal fluid cultures were concordant in only 11% of invasive infections. We conclude that pharyngeal surveillance cultures provide little clinically meaningful information and have no apparent utility in the Neonatal Intensive Care Unit setting.
Columbia University School of Public Health, New York, NY.
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L
Finelli
J R
JR
Livengood
L
L
Saiman
D000704:Analysis of Variance; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology; D015331:Cohort Studies; D015169:Colony Count, Microbial; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology / Q000382:microbiology; D006094:Gram-Positive Bacteria / Q000302:isolation & purification*; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology / Q000382:microbiology; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D008297:Male; D010614:Pharynx / Q000382:microbiology*; D011446:Prospective Studies; D012307:Risk Factors