UMEM Educational Pearls

Category: Infectious Disease

Title: Avian Influenza A or “bird flu”

Keywords: avian, influenza, infectious (PubMed Search)

Posted: 10/31/2024 by Visiting Speaker (Updated: 11/6/2024)
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By Bobbi-Jo Lowie, MD

Assistant Professor 

Emergency Medicine

University of Maryland School of Medicine

Since April of 2024 there have been 36 confirmed cases of avian influenza A across the United States. Avian influenza, primarily caused by influenza viruses that infect birds, can pose significant health risks to both animals and humans. The most notable strains include H5N1 and H7N9, with H5N1 being particularly alarming due to its high mortality rate among infected humans. The virus primarily spreads from birds to humans through direct contact with infected birds, their droppings, or contaminated environments. Although there have been recorded cases of human-to-human transmission, this usually occurs only in close-contact situations.

In humans, avian influenza can present with symptoms ranging from mild respiratory illness to severe pneumonia. Patients may experience fever, cough, sore throat, muscle aches, and in severe cases, gastrointestinal symptoms. Those that have more moderate or severe illness may develop shortness of breath, altered mental status, or seizures. Complications include acute respiratory failure, pulmonary hemorrhage among others, with respiratory failure being the most common cause of death in this patient population.

Diagnosing avian influenza involves a combination of clinical presentation, travel history, and exposure to birds and confirmation through PCR testing of upper respiratory tract samples like a nasopharyngeal swab.

 Treatment for avian influenza focuses on antiviral medications such as oseltamivir which is most effective when administered early in the course of the illness but still administered after 48 hours of illness. Supportive care is essential for managing severe cases, especially those that progress to acute respiratory distress syndrome.