BIRD FLU-H5N1 (Syllabus: GS Paper 3 – Sci and Tech)

News-CRUX-10     29th March 2024        
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Context: Scientists recently reported that the deadly H5N1 bird flu virus has spread more aggressively than ever before in wild birds and marine mammals since its arrival in South America in 2022, heightening the risk of it evolving into a larger threat to humans.

Bird Flu

  • About: Influenza A viruses can be categorized into avian influenza (commonly known as bird flu) and swine influenza (often referred to as swine flu0), depending on their origin host.

oThese viruses are distinct from human influenza viruses and do not readily spread among humans.

  • Two Categories:  

oLow pathogenicity avian influenza (LPAI) that typically causes little or no clinical signs; 

oHigh pathogenicity avian influenza (HPAI) that can cause severe clinical signs and possible high mortality rates.

  • Hosts:

oPrimary host: Wild birds, especially waterfowl, can carry the virus without showing symptoms.

oSecondary host: Domestic poultry (chickens, ducks, turkeys), where the virus can cause severe illness and high mortality rates.

  • Transmission: Typically spreads through direct contact with infected birds, their saliva, nasal secretions, and faces.

oHuman infections usually occur through close contact with infected birds or their environments.

  • Symptoms

oIn Birds: Sudden onset of severe illness, Respiratory and digestive symptoms, and High mortality rates in poultry flocks.

oIn Humans: Fever, cough, sore throat, and in severe cases, respiratory distress.

  • Human cases are rare but can be severe, with a high mortality rate.

New Type of bird flu Infection

  • The new H5N1 type first emerged in Europe in 2020, and spread rapidly to Africa and Asia. 
  • By late 2021, it had reached North America, and it appeared in South America in the fall of 2022. In February 2024, the virus raced through mainland Antarctica.