H5N2 STRAIN (Syllabus: GS Paper 3 – Sci & Tech)

Context: World Health Organization (WHO) has confirmed the first-ever human death caused by the H5N2 strain of avian influenza.

H5N2 Strain

• About: It is just one of several kinds of avian influenza viruses.

o H5 viruses have been circulating among poultry and wild birds in Mexico since the mid-1990s.

• Human Infection: Unlike other avian influenza strains that have caused outbreaks in humans, such as H1 and H3 viruses, H5 viruses rarely infect humans.
• Classification of Viruses: The viruses are classified based on two types of protein on their surfaces: hemagglutinin (H), which plays a crucial role in allowing the virus to infect cells, and neuraminidase (N), which helps the virus spread.
• H5N2 and Wild Birds: H5N2 belongs to a family of bird flu viruses called H5, which primarily infects wild birds.

o H5N1, which was detected in dairy cows in the U.S. in March, also belongs to this family.

• Symptoms: Humans may cause mild to severe upper respiratory tract infections and can be fatal. Conjunctivitis, gastrointestinal symptoms, encephalitis, and encephalopathy have also been reported.
• Diagnostic Methods: The disease is diagnosed using molecular methods like Real-Time Polymerase Chain Reaction (RT-PCR).
• Treatment: Antiviral drugs, notably neuraminidase inhibitors (oseltamivir, zanamivir), can reduce the duration of viral replication.