From the Guidelines
Avian Influenza (AI) symptoms typically include an influenza-like illness (ILI) similar to that associated with seasonal influenza, with additional gastrointestinal symptoms, severe primary viral pneumonia, lymphopenia, thrombocytopenia, and deranged liver function tests, often progressing to renal failure and multi-organ failure with high mortality. The clinical features of avian influenza A (H5N1) infection in humans are based largely on case series of hospitalized patients, with subclinical infections, mild illnesses, and atypical presentations also reported, but the frequency of such infections is difficult to determine 1. Some key symptoms and characteristics of AI include:
- Gastrointestinal symptoms present in a relatively large proportion of both adult and pediatric cases
- Severe primary viral pneumonia usually associated with lymphopenia, thrombocytopenia, and deranged liver function tests
- Renal failure and multi-organ failure may develop subsequently
- High mortality rate It is essential to note that the full spectrum of human illness associated with avian influenza A (H5N1) infection is not completely known, and the clinical features of human H5N1 disease may alter if it acquires efficient human-to-human transmission capabilities 1. In the event of suspected bird flu exposure, it is crucial to seek medical attention immediately, as treatment with antiviral medications can be effective when started promptly.
From the Research
Symptoms of Avian Influenza (AI)
The symptoms of Avian Influenza (AI) can vary depending on the subtype of the virus and the individual infected. Some common symptoms include:
- Fever greater than 38 degrees Celsius 2
- Mild cold 2
- Cough 3, 2
- Shortness of breath 3, 2
- Viral pneumonia 3, 2
- Secondary bacterial infection 3, 2
- Diarrhea 2
- Vomiting 2
- Abdominal pain 2
- Conjunctivitis (rarely diagnosed) 2
- Gastrointestinal disorder 2
- Renal and multi-organ failure 2
- Neurological signs (such as circling and ataxia) have also been recorded in cats 4
Severity of Symptoms
The severity of symptoms can range from mild to severe and fatal disease, depending on the viral subtype causing the disease 5. Avian influenza A (H5N1) has been associated with a high death rate amongst infants and young children 5. In some cases, the disease can progress rapidly to adult respiratory distress syndrome (ARDS) 3, 6.
Clinical Presentation
The clinical presentation of Avian Influenza can differ from seasonal influenza, with symptoms such as fever, cough, and shortness of breath being more severe and progressing rapidly to respiratory distress 3. The disease can also cause systemic viral dissemination, high cytokine levels, and multi-organ failure 3.