- Human infection due to avian influenza type A viruses (subtypes H5N1 and H7N9 to date). H5N1 is highly pathogenic; H7N9 has low pathogenicity.
- Presents with influenza-like illness and (primarily) lower respiratory tract symptoms
- High mortality rate in elderly and very young (particularly H5N1)
- Synonym(s): bird flu, H5N1, H7N9
- >860 confirmed human cases A(H5N1) (53% fatality rate); most cases from Egypt and Indonesia
- 1,564 cases and 610 deaths A(H7N9) (mostly from China) since February 2013
- Predominant age: affects all age groups
Etiology and Pathophysiology
- Infected poultry (domesticated ducks, turkeys, chickens) reservoir
- Low incidence of human-to-human transmission, typically household clusters and health care workers
- Incubation period: 7 days (range 2 to 17 days)
- Known direct contact with H5N1 or H7N9 virus or infected individual
- Contact with infected poultry
- Recent travel to endemic country (within 10 days of symptom onset)
- Consider isolating any patient with influenza-like symptoms who has had close contact with H5N1, H7N9, or ill poultry.
- Respiratory droplet precautions and N-95 masks
- There is an approved vaccine (H5N1) for adults 18 to 65 years of age.
- Consider antiviral chemoprophylaxis if H5N1 is circulating within the community; no postexposure chemoprophylaxis is recommended for H7N9 if travel exposure criteria are fulfilled.
Commonly Associated Conditions
Severe respiratory distress (common in severe cases)
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Domino, Frank J., et al., editors. "Avian Flu." 5-Minute Clinical Consult, 27th ed., Wolters Kluwer, 2020. Medicine Central, im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/816195/2.1/Avian_Flu.
Avian Flu. In: Domino FJF, Baldor RAR, Golding JJ, et al, eds. 5-Minute Clinical Consult. Wolters Kluwer; 2020. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/816195/2.1/Avian_Flu. Accessed June 4, 2023.
Avian Flu. (2020). In Domino, F. J., Baldor, R. A., Golding, J., & Stephens, M. B. (Eds.), 5-Minute Clinical Consult (27th ed.). Wolters Kluwer. https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/816195/2.1/Avian_Flu
Avian Flu [Internet]. In: Domino FJF, Baldor RAR, Golding JJ, Stephens MBM, editors. 5-Minute Clinical Consult. Wolters Kluwer; 2020. [cited 2023 June 04]. Available from: https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/816195/2.1/Avian_Flu.
* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Avian Flu ID - 816195 ED - Domino,Frank J, ED - Baldor,Robert A, ED - Golding,Jeremy, ED - Stephens,Mark B, BT - 5-Minute Clinical Consult, Updating UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/816195/2.1/Avian_Flu PB - Wolters Kluwer ET - 27 DB - Medicine Central DP - Unbound Medicine ER -