Pseudo-outbreak of rotavirus infection in a neonatal intensive care unit

Boon Fatt Tan; Yee-Chun Chen; Chun-Nan Lee; Luan-Yin Chang; Wu-Shiun Hsieh; Po-Nien Tsao; Ying-Chieh Liu; Mei-Ling Chen; Shu-Yuan Ho; Chun-Yi Lu; Li-Min Huang

doi:10.1016/j.jmii.2012.08.030

Pseudo-outbreak of rotavirus infection in a neonatal intensive care unit

J Microbiol Immunol Infect. 2016 Dec;49(6):947-954. doi: 10.1016/j.jmii.2012.08.030. Epub 2014 Nov 22.

Authors

Boon Fatt Tan¹, Yee-Chun Chen², Chun-Nan Lee³, Luan-Yin Chang⁴, Wu-Shiun Hsieh⁴, Po-Nien Tsao⁴, Ying-Chieh Liu⁵, Mei-Ling Chen⁵, Shu-Yuan Ho⁶, Chun-Yi Lu⁷, Li-Min Huang⁸

Affiliations

¹ Department of Pediatrics, National Taiwan University Hospital, Hsin-Chu Branch, Hsin-Chu, Taiwan.
² Center for Infection Control and Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
³ Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan; Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan.
⁴ Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan.
⁵ Center for Infection Control and Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
⁶ Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan.
⁷ Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: cylu@ntuh.gov.tw.
⁸ Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: lmhuang@ntu.edu.tw.

PMID: 25648669
DOI: 10.1016/j.jmii.2012.08.030

Abstract

Background: A rotavirus outbreak in a neonatal intensive care unit (NICU) may have catastrophic consequences for young infants receiving critical care. From May 13, 2011 to July 11, 2011, a significant increase in stool samples testing positive for rotavirus antigens in the NICU of a university affiliated hospital was observed. Due to lack of clinical presentations suggestive of rotavirus infection in the patients and the rarity of rotavirus infection in the NICU in the past, a pseudo-outbreak was suspected.

Methods: Infection control measures were reinforced initially. To investigate the outbreak, a prospective laboratory-based active surveillance of all infants in the NICU was conducted right after the cluster was identified. Repeated testing using a modified enzyme immunoassay (EIA) kit, rotavirus RNA polyacrylamide gel electrophoresis (PAGE), reverse transcription polymerase chain reaction (RT-PCR), and retrospective chart review methods were used to confirm the pseudo-outbreak.

Results: Seven infants in the NICU, with or without gastrointestinal symptoms, tested positive for the rotavirus antigen using the old version of an EIA kit, which indicated a possible outbreak. Active surveillance with repeated tests for recollected stool samples using a modified EIA kit showed negative results in all 24 infants in the NICU. Seven stored stool samples from four infants, which previously tested positive for the rotavirus antigen, tested negative for rotavirus using the modified EIA kit, PAGE, and RT-PCR. Chart reviews showed no clinical difference between index cases and controls. False positivity might arise from unsatisfactory specificity of the old EIA kit. After the introduction of the modified EIA kit, no rotavirus was detected in the NICU for at least 7 months.

Conclusion: This cluster of patients who tested positive for the rotavirus antigen in stools was confirmed to be a pseudo-outbreak. Interpretation of the old EIA for rotavirus in an NICU setting should be done with caution until the mechanism of the false-positive reaction is elucidated.

Keywords: enzyme immunoassay; neonatal; pseudo-outbreak; rotavirus.

MeSH terms

Antigens, Viral / analysis*
Disease Outbreaks
Electrophoresis, Polyacrylamide Gel
False Positive Reactions
Feces / virology
Female
Humans
Immunoenzyme Techniques / methods*
Infant, Newborn
Infection Control
Intensive Care Units, Neonatal*
Male
Reverse Transcriptase Polymerase Chain Reaction
Rotavirus / immunology
Rotavirus Infections / diagnosis*
Rotavirus Infections / virology

Substances

Antigens, Viral