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Clinical manifestations and diagnosis of avian influenza

Author
Iain Stephenson, MD, FRCP
Section Editor
Martin S Hirsch, MD
Deputy Editor
Anna R Thorner, MD

INTRODUCTION

There have been five influenza pandemics during the past 100 years, and each has been caused by the emergence of a novel virus. In the 1957 and 1968 pandemics, the new viruses contained components of previous human as well as avian influenza viruses. The origin of the influenza virus responsible for the 1918 pandemic, which killed more people in a single year than the bubonic plague, remains uncertain, but it appears to have been an adapted avian influenza strain. The emergence of a novel H1N1 human-swine-avian reassortant virus in 2009 in North America started a new pandemic. (See "Epidemiology of pandemic H1N1 influenza ('swine influenza')".)

Sporadic transmission of avian influenza H5N1 to more than 780 humans since 2003 has prompted concerns that conditions are suitable for emergence of a pandemic strain [1]. Two features of avian influenza H5N1 outbreaks are striking: the predominance of children and young adults; and the high mortality rate [2,3]. However, seroprevalence studies have found that some exposed individuals may have had a subclinical or mild infection, suggesting that the reported case-fatality rate may be an overestimate.

The clinical manifestations and diagnosis of avian influenza will be reviewed here. The epidemiology, transmission, pathogenesis, treatment, and prevention of avian influenza are discussed separately. (See "Epidemiology, transmission, and pathogenesis of avian influenza" and "Treatment and prevention of avian influenza" and "Avian influenza vaccines" and "Avian influenza A H7N9: Epidemiology, clinical manifestations, and diagnosis".)

CLINICAL FEATURES

The clinical manifestations of avian influenza are variable, being determined in part by the virus clade.

Avian influenza H5N1 — More than 840 human cases of H5N1 influenza have been reported to the World Health Organization, with a case-fatality rate of approximately 53 percent [1]. Most patients with H5N1 infection give a history of recent exposure to dead or ill poultry. H5N1 infection can result in mildly symptomatic illness to life-threatening disease. The clinical presentation may depend on the duration of exposure and the clade of the virus [4-8].

                   

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References
Top
  1. World Health Organization. Influenza at the human-animal interface. http://www.who.int/influenza/human_animal_interface/Influenza_Summary_IRA_HA_interface_13November_2015.pdf (Accessed on November 30, 2015).
  2. Stöhr K. Avian influenza and pandemics--research needs and opportunities. N Engl J Med 2005; 352:405.
  3. Bartlett JG, Hayden FG. Influenza A (H5N1): will it be the next pandemic influenza? Are we ready? Ann Intern Med 2005; 143:460.
  4. Webster RG, Govorkova EA. H5N1 influenza--continuing evolution and spread. N Engl J Med 2006; 355:2174.
  5. Yuen KY, Chan PK, Peiris M, et al. Clinical features and rapid viral diagnosis of human disease associated with avian influenza A H5N1 virus. Lancet 1998; 351:467.
  6. Oner AF, Bay A, Arslan S, et al. Avian influenza A (H5N1) infection in eastern Turkey in 2006. N Engl J Med 2006; 355:2179.
  7. Kandun IN, Wibisono H, Sedyaningsih ER, et al. Three Indonesian clusters of H5N1 virus infection in 2005. N Engl J Med 2006; 355:2186.
  8. WHO disease alerts 12th Aug 2004. Three fatal human cases of avian influenza confirmed in Viet Nam www.who.int/csr/don/2004_08_12/en/ (Accessed on February 22, 2012).
  9. Writing Committee of the Second World Health Organization Consultation on Clinical Aspects of Human Infection with Avian Influenza A (H5N1) Virus, Abdel-Ghafar AN, Chotpitayasunondh T, et al. Update on avian influenza A (H5N1) virus infection in humans. N Engl J Med 2008; 358:261.
  10. Ungchusak K, Auewarakul P, Dowell SF, et al. Probable person-to-person transmission of avian influenza A (H5N1). N Engl J Med 2005; 352:333.
  11. Wang H, Feng Z, Shu Y, et al. Probable limited person-to-person transmission of highly pathogenic avian influenza A (H5N1) virus in China. Lancet 2008; 371:1427.
  12. Katz JM, Lim W, Bridges CB, et al. Antibody response in individuals infected with avian influenza A (H5N1) viruses and detection of anti-H5 antibody among household and social contacts. J Infect Dis 1999; 180:1763.
  13. Liem NT, Tung CV, Hien ND, et al. Clinical features of human influenza A (H5N1) infection in Vietnam: 2004-2006. Clin Infect Dis 2009; 48:1639.
  14. de Jong MD, Bach VC, Phan TQ, et al. Fatal avian influenza A (H5N1) in a child presenting with diarrhea followed by coma. N Engl J Med 2005; 352:686.
  15. Guan Y, Poon LL, Cheung CY, et al. H5N1 influenza: a protean pandemic threat. Proc Natl Acad Sci U S A 2004; 101:8156.
  16. Shortridge KF, Zhou NN, Guan Y, et al. Characterization of avian H5N1 influenza viruses from poultry in Hong Kong. Virology 1998; 252:331.
  17. Beigel JH, Farrar J, Han AM, et al. Avian influenza A (H5N1) infection in humans. N Engl J Med 2005; 353:1374.
  18. Tran TH, Nguyen TL, Nguyen TD, et al. Avian influenza A (H5N1) in 10 patients in Vietnam. N Engl J Med 2004; 350:1179.
  19. Centers for Disease Control and Prevention. Health Alert Network. Human infection with avian influena A (H5N1) virus http://www.bt.cdc.gov/HAN/han00360.asp (Accessed on January 16, 2014).
  20. World Health Organization. Human infection with avian influenza A(H5N1) virus - update. http://www.who.int/csr/don/2014_01_09_h5n1/en/index.html (Accessed on January 13, 2014).
  21. ProMED mail. Avian influenza, human (13): Canada ex China (BJ) H5N1, fatal, case report. http://www.promedmail.org/direct.php?id=20140112.2167282 (Accessed on January 16, 2014).
  22. Bridges CB, Lim W, Hu-Primmer J, et al. Risk of influenza A (H5N1) infection among poultry workers, Hong Kong, 1997-1998. J Infect Dis 2002; 185:1005.
  23. Chotpitayasunondh T, Ungchusak K, Hanshaoworakul W, et al. Human disease from influenza A (H5N1), Thailand, 2004. Emerg Infect Dis 2005; 11:201.
  24. Kawachi S, Luong ST, Shigematsu M, et al. Risk parameters of fulminant acute respiratory distress syndrome and avian influenza (H5N1) infection in Vietnamese children. J Infect Dis 2009; 200:510.
  25. Peiris JS, Yu WC, Leung CW, et al. Re-emergence of fatal human influenza A subtype H5N1 disease. Lancet 2004; 363:617.
  26. To KF, Chan PK, Chan KF, et al. Pathology of fatal human infection associated with avian influenza A H5N1 virus. J Med Virol 2001; 63:242.
  27. Koopmans M, Wilbrink B, Conyn M, et al. Transmission of H7N7 avian influenza A virus to human beings during a large outbreak in commercial poultry farms in the Netherlands. Lancet 2004; 363:587.
  28. Nguyen-Van-Tam JS, Nair P, Acheson P, et al. Outbreak of low pathogenicity H7N3 avian influenza in UK, including associated case of human conjunctivitis. Euro Surveill 2006; 11:E060504.2.
  29. Centers for Disease Control and Prevention (CDC). Notes from the field: Highly pathogenic avian influenza A (H7N3) virus infection in two poultry workers--Jalisco, Mexico, July 2012. MMWR Morb Mortal Wkly Rep 2012; 61:726.
  30. Peiris M, Yuen KY, Leung CW, et al. Human infection with influenza H9N2. Lancet 1999; 354:916.
  31. WHO disease alerts: 5th April 2004. Avian influenza H7 human infections in Canada www.who.int/csr/don/2004_04_05/en/ (Accessed on February 02, 2012).
  32. Centers for Disease Control and Prevention. Interim guidance for laboratory testing of persons with suspected infection with highly pathogenic avian influenza A (H5N1) virus in the United States. http://www.cdc.gov/flu/avianflu/guidance-labtesting.htm (Accessed on September 11, 2012).
  33. World Health Organization. Recommended laboratory tests to identify influenza A/H5 virus in specimens from patients with an influenza-like illness. 2005. http://www.cdc.gov.tw/public/Attachment/11289223671.pdf (Accessed on February 22, 2012).
  34. Rowe T, Abernathy RA, Hu-Primmer J, et al. Detection of antibody to avian influenza A (H5N1) virus in human serum by using a combination of serologic assays. J Clin Microbiol 1999; 37:937.
  35. Centers for Disease Control and Prevention (CDC). Outbreaks of avian influenza A (H5N1) in Asia and interim recommendations for evaluation and reporting of suspected cases--United States, 2004. MMWR Morb Mortal Wkly Rep 2004; 53:97.
  36. Majury A, Ash J, Toye B, et al. Laboratory diagnosis of human infection with avian influenza. CMAJ 2006; 175:1371.
  37. FDA Clears New CDC Test to Detect Human Influenza http://www.hhs.gov/news/press/2008pres/09/20080930a.html (Accessed on February 22, 2012).
  38. Uyeki TM. Human infection with highly pathogenic avian influenza A (H5N1) virus: review of clinical issues. Clin Infect Dis 2009; 49:279.
  39. World Health Organization. WHO recommendations on the use of rapid testing for influenza diagnosis http://www.who.int/influenza/resources/documents/rapid_testing/en/index.html (Accessed on February 22, 2012).
  40. Kitphati R, Apisarnthanarak A, Chittaganpitch M, et al. A nationally coordinated laboratory system for human avian influenza A (H5N1) in Thailand: program design, analysis, and evaluation. Clin Infect Dis 2008; 46:1394.