Hostname: page-component-77f85d65b8-6c7dr Total loading time: 0 Render date: 2026-03-29T21:41:38.025Z Has data issue: false hasContentIssue false
  • English
  • Français

Case-Control Study of Clinical Features of Influenza in Hospitalized Patients

Published online by Cambridge University Press:  02 January 2015

Hilary M. Babcock ,
Liana R. Merz ,
Erik R. Dubberke  and
Victoria J. Fraser
Hilary M. Babcock*
Affiliation:
Washington University School of Medicine, Infectious Diseases Division, St. Louis, Missouri
Liana R. Merz
Affiliation:
Washington University School of Medicine, Infectious Diseases Division, St. Louis, Missouri
Erik R. Dubberke
Affiliation:
Washington University School of Medicine, Infectious Diseases Division, St. Louis, Missouri
Victoria J. Fraser
Affiliation:
Washington University School of Medicine, Infectious Diseases Division, St. Louis, Missouri
*
Medical Director of Occupational Health (Infectious Diseases), Barnes-Jewish and St. Louis Children's Hospitals, Assistant Professor of Medicine, Infectious Disease Division, Washington University School of Medicine, Campus Box 8051, 660 S. Euclid Ave., St. Louis, MO 63110 (hbabcock@im.wustl.edu)
Get access Rights & Permissions [Opens in a new window]

Abstract

Background.

The symptoms of influenza infection in outpatients are well described. The Centers for Disease Control and Prevention (CDC) definition of an influenza-like illness (ILI) includes fever and cough or sore throat. Few data exist on the clinical presentation of influenza in hospitalized patients, which may be distinct from the clinical presentation of influenza in ambulatory patients because of underlying medical conditions and medications.

Design.

Retrospective case-control study.

Setting.

A 1,250-bed urban teaching hospital.

Patients.

A total of 369 patients were admitted to the general medicine wards during 3 consecutive influenza seasons (2001-2004): 123 case patients with laboratory-confirmed influenza that was diagnosed during routine medical care and 246 control patients with active surveillance culture results negative for influenza.

Methods.

Data on demographic characteristics, comorbidities, and signs and symptoms were obtained from a review of the medical records of the case and control patients. Analysis included stratified analysis and logistic regression.

Results.

Cough, coryza, sore throat, and fever were more common in patients with influenza infection. The CDC's definition of an ILI had a sensitivity of 43% and specificity of 86% in the study population, with a crude odds ratio (OR) of 4.7 (95% confidence interval [CI], 2.8-7.8). The sensitivity of the CDC's definition of an ILI decreased to 21% among asthmatic patients, who had similar rates of fever and/or ILI with or without influenza. By logistic regression, ILI was strongly associated with influenza infection in patients without asthma (adjusted OR, 7.5 [95% CI, 4.1-13.7]) but not in patients with asthma (adjusted OR, 1.1 [95% CI, 0.13-10]). The positive predictive value of an ILI in asthmatic patients was 50%.

Conclusions.

The CDC's definition of an ILI lacks sensitivity among hospitalized patients, and the presence of an ILI is not associated with influenza infection in asthmatic patients.

Information

Type
Original Article
Information
Infection Control & Hospital Epidemiology , Volume 29 , Issue 10 , October 2008 , pp. 921 - 926
Copyright
Copyright © The Society for Healthcare Epidemiology of America 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

1.Bridges, CB, Thompson, WW, Meltzer, MI, et al.Effectiveness and cost-benefit of influenza vaccination of healthy working adults: a randomized controlled trial. JAMA 2000;284:1655–1663.Google Scholar
2.Govaert, TM, Dinant, GJ, Aretz, K, Knottnerus, JA. The predictive value of influenza symptomatology in elderly people. Fam Pract 1998;15:16–22.Google Scholar
3.Neuzil, KM, O'Connor, TZ, Gorse, GJ, Nichol, KL. Recognizing influenza in older patients with chronic obstructive pulmonary disease who have received influenza vaccine. Clin Infect Dis 2003;36:169–174.CrossRefGoogle ScholarPubMed
4.Boivin, G, Hardy, I, Tellier, G, Maziade, J. Predicting influenza infections during epidemics with use of a clinical case definition. Clin Infect Dis 2000;31:1166–1169.Google Scholar
5.Carrat, F, Tachet, A, Rouzioux, C, Housset, B, Valleron, AJ. Evaluation of clinical case definitions of influenza: detailed investigation of patients during the 1995–1996 epidemic in France. Clin Infect Dis 1999;28:283–290.Google Scholar
6.Monto, AS, Gravenstein, S, Elliott, M, Colopy, M, Schweinle, J. Clinical signs and symptoms predicting influenza infection. Arch Intern Med 2000;160:3243–3247.Google Scholar
7.Ebell, MH, White, LL, Casault, T. A systematic review of the history and physical examination to diagnose influenza. J Am Board Fam Pract 2004;17:1–5.Google Scholar
8.Monmany, J, Rabella, N, Margall, N, Domingo, P, Gich, I, Vazquez, G. Unmasking influenza virus infection in patients attended to in the emergency department. Infection 2004;32:89–97.Google Scholar
9.Friedman, MJ, Attia, MW. Clinical predictors of influenza in children. Arch Pediatr Adolesc Med 2004;158:391–394.Google Scholar
10.Monto, AS, Rotthoff, J, Teich, E, et al.Detection and control of influenza outbreaks in well-vaccinated nursing home populations. Clin Infect Dis 2004;39:459–464.Google Scholar
11.Thursky, K, Cordova, SP, Smith, D, Kelly, H. Working towards a simple case definition for influenza surveillance. J Clin Virol 2003;27:170–179.Google Scholar
12.Aguilera, JF, Paget, WJ, Mosnier, A, et al.Heterogeneous case definitions used for the surveillance of influenza in Europe. Eur J Epidemiol 2003;18:751–754.CrossRefGoogle ScholarPubMed
13.Nichol, KL, Mendelman, P. Influence of clinical case definitions with differing levels of sensitivity and specificity on estimates of the relative and absolute health benefits of influenza vaccination among healthy working adults and implications for economic analyses. Virus Res 2004;103:3–8.CrossRefGoogle ScholarPubMed
14.Taylor, JL, Dwyer, DM, Coffman, T, Groves, C, Patel, J, Israel, E. Nursing home outbreak of influenza A (H3N2): evaluation of vaccine efficacy and influenza case definitions. Infect Control Hosp Epidemiol 1992;13:93–97.Google Scholar
15.Centers for Disease Control and Prevention. Influenza: reports and surveillance methods in the United States. Available at: http://www.cdc.gov/flu/weekly/fluactivity.htm. Accessed January 9, 2007.Google Scholar
16.Falsey, AR, Cunningham, CK, Barker, WH, et al.Respiratory syncytial virus and influenza A infections in the hospitalized elderly. J Infect Dis 1995;172:389–394.CrossRefGoogle ScholarPubMed
17.Oliveira, EC, Marik, PE, Colice, G. Influenza pneumonia: a descriptive study. Chest 2001;119:1717–1723.Google Scholar
18.Walsh, EE, Cox, C, Falsey, AR. Clinical features of influenza A virus infection in older hospitalized persons. J Am Geriatr Soc 2002;50:1498–1503.Google Scholar
19.Bennet, NM. Diagnosis of Influenza. Med J Aust 1973; Suppl:19–22.Google Scholar
20.Bisno, A, Griffin, JP, VanEpps, KA, Niell, HB, Rytel, M. Pneumonia and Hong Kong influenza: a prospective study of the 1968–1969 epidemic. Am J Med Sci 1971;261:251–263.Google Scholar
21.Babcock, HM, Merz, LR, Fraser, VJ. Is influenza an influenza-like illness? Clinical presentation of influenza in hospitalized patients. Infect Control Hosp Epidemiol 2006;27:266–270.Google Scholar
22.van den Dool, C, Hak, E, Wallinga, J, van Loon, A, Lammers, J, Bonten, M. Symptoms of influenza virus infection in hospitalized patients. Infect Control Hosp Epidemiol 2008;29:314–319.Google Scholar
23.Call, SA, Vollenweider, MA, Hornung, CA, Simel, DL, McKinney, WP. Does this patient have influenza? JAMA 2005;293:987–997.Google Scholar
24.Azevedo, AM, Durigon, EL, Okasima, V, et al.Detection of influenza, parainfluenza, adenovirus and respiratory syncytial virus during asthma attacks in children older than 2 years old. Allergol Immunopathol (Madr) 2003;31:311–317.Google Scholar