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Published on: May 1, 2021
Conjunctival colonization of infants hospitalized in a neonatal intensive care unit: a longitudinal analysis
Craig H Raskind1, Barbara E Sabo, Deborah A Callan
1Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8064, USA.
Insights
Conjunctival colonization is common in NICU infants, with prolonged stays increasing the risk of pathogenic bacteria. Physical signs like redness and swelling are more frequent with non-CoNS isolates.
Area of Science:
- Neonatal Medicine
- Infectious Diseases
- Microbiology
Background:
- Neonatal intensive care units (NICUs) are high-risk environments for healthcare-associated infections.
- Conjunctival colonization in neonates can be a precursor to serious infections.
Purpose of the Study:
- To determine the frequency and types of conjunctival colonization in NICU infants.
- To correlate culture results with observed physical findings.
- To assess the impact of hospitalization duration on colonization patterns.
Main Methods:
- A surveillance study was conducted in a Level III NICU over 26 weeks.
- Weekly bacterial conjunctival cultures were performed on all eligible infants.
- Conjunctival appearance was recorded concurrently with cultures.
Main Results:
- Of 319 infants, 58% had at least one positive conjunctival culture, yielding 494 isolates from over 18 species.
- Coagulase-negative Staphylococcus (CoNS) was the most common isolate (75%).
- Non-CoNS isolates increased with hospitalization duration, and were associated with conjunctival edema, erythema, or exudates (30% vs 13% for CoNS alone).
Conclusions:
- Conjunctival colonization is prevalent in NICU infants.
- Prolonged hospitalization increases the risk of colonization by potentially pathogenic organisms.
- Physical findings are more indicative of non-CoNS conjunctival isolates.
Objectives:
To determine the frequency of conjunctival colonization, identify the colonizing flora, and correlate culture results with physical findings in infants in a NICU.
Design:
Surveillance study.
Setting:
Level III NICU of a large university teaching hospital.
Patients:
All infants admitted for longer than 24 hours during a 26-week period.
Methods:
Weekly bacterial conjunctival cultures were performed for all infants. The conjunctival appearance at the time of culture was recorded. The frequency, identity, and correlation of culture results with physical findings were determined.
Results:
One thousand ninety-one cultures were performed for 319 infants: 133 (42%) had no positive cultures and 186 (58%) had at least one positive culture. Culture analysis revealed that 411 (38%) were positive and yielded 494 isolates comprising more than 18 bacterial species. Bacteria most commonly isolated included coagulase-negative Staphylococcus (CoNS) (75%), viridans group streptococci (8.7%), Staphylococcus aureus (3.8%), Enterococcus species (2.6%), and Serratia marcescens (2.4%). The frequency of non-CoNS isolates increased significantly during the first 6 weeks of patient hospital stay (6% [1 to 3 weeks] to 12% [4 to 6 weeks]; P = .01), with an increasing trend to 15 weeks (18%). Correlation of bacteriologic results with physical findings demonstrated that infants with non-CoNS isolates exhibited conjunctival edema, erythema, or exudates more frequently than did infants with CoNS alone (30% vs 13%; P = .0001).
Conclusions:
Conjunctival colonization was common among infants in a NICU. Prolonged hospitalization predisposes to colonization with potentially pathogenic organisms. Physical findings were more likely in patients with non-CoNS conjunctival isolates.
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