H5N2 - SCI & TECH
News: First human death from H5N2
bird flu: Why are experts concerned?
What's in the news?
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The World Health Organization (WHO) has confirmed
the first-ever human death caused by the H5N2 strain of avian influenza.
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The victim was a 59-year-old resident of the State
of Mexico with underlying health conditions.
Avian Influenza:
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Avian influenza, or bird flu, is a viral infection primarily affecting birds.
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Certain subtypes can infect humans, causing severe
respiratory illnesses.
Notable Subtypes - H5N1, H7N9, and now H5N2.
Issues:
1. Zoonotic Nature:
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Avian influenza is a zoonotic disease, meaning it
can spread from animals to humans.
2. Global Risks:
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The interconnected nature of global poultry trade
and international travel could facilitate the rapid spread of the virus.
H5N2 Bird Flu:
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H5N2 is a subtype of the Influenza A virus that
primarily affects birds but can also pose risks to humans and other animals.
Virology:
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It is a single-stranded
RNA virus.
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Structure:
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Hemagglutinin (H): H5 type, responsible for
virus entry into host cells.
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Neuraminidase (N): N2 type, facilitates virus
release from host cells.
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High mutation rates and genetic reassortment with
other influenza viruses can lead to new variants, complicating control
measures.
Transmission:
Primary Hosts:
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Wild Birds - Natural reservoir, often asymptomatic carriers.
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Domestic Poultry - Highly susceptible, can suffer severe outbreaks.
Transmission Methods:
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Direct Contact - Infected birds shed the virus through saliva,
nasal secretions, and feces.
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Indirect Contact - Contaminated surfaces, water, and feed.
Human Infection:
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Rare but possible, typically through close contact
with infected birds or contaminated environments.
Symptoms and Effects:
In Birds:
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Respiratory Symptoms - Coughing, sneezing, nasal
discharge.
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Gastrointestinal Symptoms - Diarrhea.
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Neurological Symptoms - Tremors, incoordination.
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General Symptoms - Lethargy, decreased egg production, sudden death
in severe cases.
In Humans:
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Mild Cases - Conjunctivitis, mild flu-like symptoms.
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Severe Cases - Pneumonia, acute respiratory distress syndrome
(ARDS), and potentially death.
Outbreaks:
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2014-2015 - Major outbreak in North America, leading to the
culling of millions of poultry.
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2021-2022 - Outbreaks in various regions, including Europe
and Asia, prompting widespread control measures.
Economic Impact:
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Poultry Industry - Significant losses due to culling and trade
restrictions.
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Global Trade - Disruption of poultry products' international
trade.
Vaccination:
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Birds - Vaccination programs to reduce susceptibility and
spread among poultry.
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Humans - No specific vaccine for H5N2, but seasonal flu
vaccines may offer partial protection.