Expired CME Article

Clinical Manifestations and Diagnosis of Influenza

Authors: Mahmoud Shorman, MD, Jonathan P. Moorman, MD

Abstract

Infection with influenza presents as a spectrum of disease ranging from patients who are asymptomatic to those with fulminant primary viral pneumonia, depending on host immune status and the dose of virus. There is generally an abrupt onset of symptoms after an asymptomatic incubation period of a few days. Uncomplicated influenza usually presents as tracheobronchitis with involvement of the small airways 1 (Table 1), with systemic symptoms that are usually described first by the patient in abrupt fashion and include fever, chills, cough, myalgias (involving the long muscles of the back and the extremities), malaise, headache, and anorexia. Cough that usually changes in nature from dry to productive, as well as headache and myalgia, seem to be the most prominent symptoms. 2,3 The illness usually affects cigarette smokers in a more severe fashion.

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References

1. Walsh JJ, Dietlein LF, Low FN, et al. Bronchotracheal response in human influenza type A, Asian strain, as studied by light and electron microscopic examination of bronchoscopic biopsies. Arch Intern Med 1961; 108: 376–388.
 
2. Nicholson KG. Clinical features of influenza. Semin Respir Infect 1992; 7: 26–37.
 
3. Stuart-Harris CH. Twenty years of influenza epidemics. Am Rev Respir Dis 1961; 83: 54–75.
 
4. Kark JD, Lebiush M, Rannon L. Cigarette smoking as a risk factor for epidemic A(H1N1) influenza in young men. N Engl J Med 1982; 307: 1042–1046.
 
5. Kilbourne ED, Loge JP. Influenza A prime: A clinical study of an epidemic caused by a new strain of virus. Ann Intern Med 1950; 33: 371–382.
 
6. Ledder SR, Gill PW, Peat JK. Short and long term effects on influenza A on lung function. Med J Aust 1974; 2: 812–814.
 
7. Smith CB, Kanner RE, Golden CA, et al. Effect of viral infections on pulmonary function in patients with chronic obstructive pulmonary diseases. J Infect Dis 1980; 141: 271–280.
 
8. Nigg C, Eklund CM, Wilson DE, et al. Study of an epidemic of influenza B. Am J Hyg 1942; 35: 265–284.
 
9. Baine WB, Luby JP, Martin SM. Severe illness with influenza B. Am J Med 1980; 68: 181–189.
 
10. Mogabgab WJ. Viruses associated with respiratory illnesses in adults. Ann Intern Med 1963; 59: 306–311.
 
11. Glezen WP, Loda FA, Clyde WA Jr, et al. Epidemiologic patterns of acute lower respiratory disease of children in a pediatric group practice. J Pediatr 1971; 78: 397–406.
 
12. Glezen WP, Paredes A, Taber LH. Influenza in children: Relationship to other respiratory agents. JAMA 1980; 243: 1345–1349.
 
13. Kim HW, Brandt CD, Arrobio JO, et al. Influenza A and B virus infection in infants and young children during the years 1957–1976. Am J Epidemiol 1979; 109: 464–479.
 
14. 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.
 
15. Cram P, Blitz SG, Monto A, et al. Diagnostic testing for influenza: Review of current status and implications of newer treatment options. Am J Manag Care 1999; 5: 1555–1563.
 
16. Newton DW, Treanor JJ, Menegus MA. Clinical and laboratory diagnosis of influenza virus infections. Am J Manag Care 2000; 6( 5 Suppl): S265–S275.
 
17. Hulson TD, Mold JW, Scheid D, et al. Diagnosing influenza: The value of clinical clues and laboratory tests. J Fam Pract 2001; 50: 1051–1056.
 
18. Daisy JA, Lief FS, Friedman HM. Rapid diagnosis of influenza A infection by direct immunofluorescence of nasopharyngeal aspirates in adults. J Clin Microbiol 1979; 9: 688–692.
 
19. Leonardi GP, Leib H, Birkhead GS, et al. Comparison of rapid detection methods for influenza A virus and their value in health-care management of institutionalized geriatric patients. J Clin Microbiol 1994; 32: 70–74.
 
20. Waner JL, Todd SJ, Shalaby H, et al. Comparison of Directigen FLU-A with viral isolation and direct immunofluorescence for the rapid detection and identification of influenza A virus. J Clin Microbiol 1991; 29: 479–482.
 
21. Espy MJ, Smith TF, Harmon MW, et al. Rapid detection of influenza virus by shell vial assay with monoclonal antibodies. J Clin Microbiol 1986; 24: 677–679.
 
22. St George K, Patel NM, Hartwig RA, et al. Rapid and sensitive detection of respiratory virus infections for directed antiviral treatment using R-Mix cultures. J Clin Virol 2002; 24: 107–115.
 
23. van Elden LJ, van Essen GA, Boucher CA, et al. Clinical diagnosis of influenza virus infection: Evaluation of diagnostic tools in general practice. Br J Gen Pract 2001; 51: 630–634.
 
24. Zambon M, Hays J, Webster A, et al. Diagnosis of influenza in the community: Relationship of clinical diagnosis to confirmed virological, serologic, or molecular detection of influenza. Arch Intern Med 2001; 161: 2116–2122.
 
25. Hak E, Moons KG, Verheij TJ, et al. Clinical signs and symptoms predicting influenza infection. Arch Intern Med 2001; 161: 1351–1352(letter).