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An Outbreak of Influenza A in a Neonatal Intensive Care Unit

  • Robert J. Cunney (a1), Anne Bialachowski (a1), Diane Thornley (a1), Fiona M. Smaill (a1) and Ross A. Pennie (a1)...



Investigation of an outbreak of influenza A in a neonatal intensive care unit (NICU) with examination of risk factors for infection and outcomes.


Retrospective cohort study of infants admitted to the unit during the outbreak period. Prospective survey of NICU staff and mothers of infants in the cohort study.


Level III nursery in a university-affiliated tertiary referral center.


Nineteen infants in the NICU were infected with influenza A. There were six symptomatic cases and one death who had evidence of virus-associated hemophagocytic syndrome at autopsy. Amantadine prophylaxis was offered to the NICU staff, and amantadine therapy was given to five of the six symptomatic infants. Mechanical ventilation, gestational age, birth weight, Clinical Risk Index for Babies score, and twin pregnancy were associated with acquisition of influenza A on univariate analysis. Mechanical ventilation (odds ratio [OR], 6.2; P=.02) and twin pregnancy (OR, 7.0; P=.04) remained as significant risk factors for infection on multiple logistic regression analysis. Only 15% of respondents to the NICU staff survey were vaccinated against influenza. There was no association between a history of an influenza-like illness during pregnancy and acquisition of influenza A by infants of mothers who responded to the maternal survey (OR, 0.91; P=1.0).


Influenza A is an important pathogen in the neonatal population and is readily transmissible in the NICU setting.


Corresponding author

Dept Microbiology, McMaster University Medical Centre, 1200 Main St W, Hamilton, ON L8N 3Z5, Canada


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1. Bauer, CR, Elie, K, Spence, L, Stern, L. Hong Kong influenza in a neonatal unit. JAMA 1973;223:12331235.
2. Meibalane, R, Sedmark, GV, Sasidharan, P, Garg, P, Grausz, JP. Outbreak of influenza in a neonatal intensive care unit. J Pediatr 1977;91:974976.
3. Joshi, VV, Escobar, MR, Stewart, L, Bates, RD. Fatal influenza A2 viral pneumonia in a newborn infant. Am J Dis Child 1973;126:839840.
4. Puck, JM, Glezen, WP, Frank, AL, Six, HR. Protection of infants from infection with influenza A virus by transplacentally acquired antibody. J Infect Dis 1980;142:844849.
5. The International Neonatal Network. The CRIB (Clinical Risk Index for Babies) score: a tool for assessing initial neonatal risk and comparing performance of neonatal intensive care units. Lancet 1993;342:193198.
6. Garner, JS, the Hospital Infection Control Practices Advisory Committee. Guideline for isolation precautions in hospitals. Infect Control Hosp Epidemiol 1996;17:5380.
7. American Academy of Pediatrics and American College of Obstetricians and Gynecologists. Inpatient perinatal care services. In: Hauth, JC, Merenstein, GB, eds. Guidelines for Perinatal Care. 4th ed. Elk Grove Village, IL: American Academy of Pediatrics; 1997:1350.
8. Laboratory Centre for Disease Control. Influenza to Canada: 1997-1998 season. CCDR 1998;24:169176.
9. Dagan, R, Hall, CB. Influenza A virus infection imitating bacterial sepsis in early infancy. Pediatr Infect Dis J 1984;3:218221.
10. Potter, MN, Foot, AB, Oakhill, A. Influenza A and the virus associated haemophagocytic syndrome: cluster of three cases to children with acute leukaemia. J Clin Pathol 1991;44:297299.
11. Haley, RW, Cushion, NB, Tenover, FC, Bannerman, TL, Dryer, D, Ross, J, et al. Eradication of endemic methicillin-resistant Staphylococcus aureus infections from a neonatal intensive care unit. J Infect Dis 1995;171:614624.
12. Haley, RW, Bregman, DA. The role of understaffing and overcrowding in recurrent outbreaks of staphylococcal infection to a neonatal special–care unit. J Infect Dis 1982;145:875885.
13. Moisiuk, SE, Robson, D, Klass, L, Kliewer, G, Wasyliuk, W, Dari, M, et al. Outbreak of parainfluenza virus type 3 to an intermediate care neonatal nursery. Pediatr Infect Dis J 1998;17:4953.
14. Valenti, WM, Clarke, TA, Hall, CB, Menegus, MA, Shapiro, DL. Concurrent outbreaks of rhinovirus and respiratory syncytial virus to an intensive care nursery: epidemiology and associated risk factors. J Pediatr 1982;100:722726.
15. Wilson, CW, Stevenson, DK, Arvin, AM. A concurrent epidemic of respiratory syncytial virus and echovirus 7 infections in an intensive care nursery. Pediatr Infect Dis J 1989;8:2429.
16. Nagels, B, Ritter, E, Thomas, P, Schulte-Wisserman, H, Wirsing von Konig, CH. Acinetobader baumannii colonization in ventilated preterm infants. Eur J Clin Microbiol Infect Dis 1998;17:3740.
17. Cordero, L, Ayers, LW, Davis, K. Neonatal airway colonization with gram-negative bacilli: association with severity of bronchopulmonary dysplasia. Pediatr Infect Dis J 1997;16:1823.
18. Garcia, DC, Trevisan, AR, Botto, L, Cervetto, M, Sarubbi, MA, Zorzopulos, J. An outbreak of multiply resistant Pseudomonas aeruginosa to a neonatal unit: plasmid pattern analysis. J Hosp Infect 1989;14:99105.
19. de Sierra, TM, Kumar, ML, Wasser, TE, Murphy, BR, Subbarao, EK. Respiratory syncytial virus-specific immunoglobulins to preterm infants. J Pediatr 1993;122:787791.
20. Simoes, EAF, King, SJ, Lehr, MV, Groothius, JR. Preterm twins and triplets: a high-risk group for severe respiratory syncytial virus infection. Am J Dis Child 1993;147:303306.
21. Dominguez, EA, Taber, LH, Couch, RB. Comparison of rapid diagnostic techniques for respiratory syncytial and influenza A virus respiratory infections to young children. J Clin Microbiol 1993;31:22862290.
22. Hijazi, Z, Pacsa, A, Eisa, S, el Shazli, A, abd el-Salam, RA. Laboratory diagnosis of acute lower respiratory tract viral infections in children. J Trop Pediatr 1996;42:276280.
23. Wiselka, M. Influenza: diagnosis, management, and prophylaxis. BMJ 1994;308:13411345.
24. Englund, JA, Champlin, RE, Wyde, PR, Kantarjian, H, Atmar, RL, Tarrand, J, et al. Common emergence of amantadine- and rimantadine-resistant influenza A viruses in symptomatic immunocompromised adults. Clin Infect Dis 1998;26:14181424.
25. Klimov, AI, Rocha, E, Hayden, FG, Shult, PA, Roumillat, LF, Cox, NJ. Prolonged shedding of amantadine-resistant influenzae A viruses by immunodeficient patients: detection by polymerase chain reaction-restriction analysis. J Infect Dis 1995;172:13521355.
26. Hayden, FG, Osterhaus, ADME, Treanor, JJ, Hayden, FG, Osterhaus, AD, Treanor, JJ, et al. Efficacy and safety of the neuraminidase inhibitor zanamivir to the treatment of influenza virus infections. N Engl J Med 1997;337:874880.
27. Hayden, FG, Treanor, JJ, Fritz, RS, Lobo, M, Betts, RF, Miller, M, et al. Use of the oral neuraminidase inhibitor oseltamivir to experimental human influenza: randomized controlled trials for prevention and treatment. JAMA 1999;282:12401246.
28. Monto, AS, Robinson, DP, Herlocher, ML, Hinson, JM Jr, Elliott, MJ, Crisp, A. Zanamivir in the prevention of influenza among healthy adults: a randomized controlled trial. JAMA 1999;282:3135.
29. Hayden, FG, Atmar, RL, Schilling, M, Johnson, C, Poretz, D, Paar, D, et al. Use of the selective oral neuraminidase inhibitor oseltamivir to prevent influenza. N Engl J Med 1999;341:13361343.
30. Eisenfeld, L, Perl, L, Burke, G, Blackington, S, York, E, Regan, H, et al. Lack of compliance with influenza immunization for caretakers of neonatal intensive care unit patients. Am J Infect Control 1994;22:307311.
31. Centers for Disease Control and Prevention. Update: influenza activity—United States: 1997-98 season. MMWR 1998;47:196200.
32. Centers for Disease Control and Prevention. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 1998;47:126.
33. Weingarten, S, Staniloff, H, Ault, M, Miles, P, Bamberger, M, Meyer, RD. Influenza surveillance in an acute care hospital. Arch Intern Med 1988;148:113116.


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