H5N5 Avian Influenza

Why in news?

The H5N5 bird flu has recently made headlines after the first-ever human case was confirmed in the United States in November 2025.

• H5N5 – It is a subtype of the avian influenza A virus, primarily affecting wild and domestic birds like ducks, geese, and poultry.
• Risks associated with the emergence of H5N5 –
  • Genetic Diversity – Influenza A (H5) viruses come in many forms due to high genetic variation.
  • Reassortment Risk – These viruses can shuffle genetic material (reassort), leading to new, unpredictable variants (as per the World Organization for Animal Health).
  • Low Current Risk – The current threat may be limited, but the underlying pandemic potential calls for proactive monitoring of animal hosts.
• Spread of H5N5 flu –
  • In Birds – the virus spreads through respiratory secretions and feces, common in poultry farms, live bird markets, and wild bird populations.
  • In Humans - Infection occurs via close, unprotected contact with infected birds or contaminated environments.
• Transmission – It can occur via droplets, dust, or by touching surfaces contaminated with bird secretions and then touching one's eyes, nose, or mouth.
• Symptoms – It can range from asymptomatic or mild to very severe symptoms.
  • In humans - include fever, cough, sore throat, shortness of breath, fatigue, muscle aches, eye symptoms (conjunctivitis) and sometimes gastrointestinal issues like vomiting or diarrhea.
  • Severe cases can lead to pneumonia, acute respiratory distress, or death.
• Prevention –
  • Avoid close contact with sick or dead birds.
  • Use appropriate protective gear (masks, gloves) when handling poultry or cleaning bird coops.
  • Avoid raw or undercooked poultry, meat, eggs, and raw milk from infected animals.
  • Public health agencies recommend ongoing surveillance and rapid detection of new human infections.

To know about H5N1 vs H5N2, Click here

References

1. The Hindu | U.S. resident infected with H5N5
2. NDTV | US Reports World's First Human Case Of H5N5 Bird Flu.