The Hindu Editorial Summary : Zika, Dengue Viruses and The PS Deception

GS-2 Mains : Health

Revision Notes 

Question : Discuss the significance of viral transmission in the life cycle of viruses, emphasizing their evolutionary adaptations for successful transmission.

Transmission: A Crucial Event in a Virus’s Life Cycle

• Viruses need to be transmitted to new hosts to survive and replicate.
• Successful viruses have evolved adaptations to ensure they can jump to new hosts.
• This is usually achieved by being present in bodily fluids that come in contact with the environment.

Viruses and Tropism

• Viruses are selective about the cells they infect (tropism).
• This selectivity is determined by special proteins on the virus’s surface that bind to specific receptors on host cells.
• For example:
  • HIV infects cells with the CD4 receptor (T-cells and macrophages).
  • SARS-CoV-2 infects cells with the ACE2 receptor (respiratory tract and some cardiovascular cells).

Viral Transmission: A Race Against the Immune System

• Viruses must transmit before the immune system destroys them or the host dies.
• One strategy viruses use is to have proteins that bind to receptors on multiple cell types, allowing them to infect different cells and be present in multiple fluids for faster transmission.

The PS Receptor: A Decoy for Viruses

• Phosphatidyl serine (PS) is a protein expressed by dying cells to signal the immune system for removal.
• Immune cells have receptors for PS and destroy these cells.
• Viruses can mimic this process (apoptotic mimicry) by expressing PS on their surface, allowing them to infect immune cells that would destroy them.
• Since the PS receptor is on many cells, the virus can be present in multiple body fluids (saliva, semen).

The Body’s Defense Mechanism

• Extracellular vesicles (fat-enclosed structures) in bodily fluids can inhibit viral infection.
• These vesicles are abundant in saliva and semen and contain PS proteins that viruses like Zika use for infection.
• The concentration of PS-containing vesicles is high in saliva and semen and low in blood.
• These PS-coated vesicles compete with viruses for the same receptor sites, preventing viral entry into cells.

Conclusion

• The discovery of PS-coated vesicles for immunity is a new finding in host defense against viruses.
• While future applications are unclear, it opens doors for further research.

 

 

The Hindu Editorial Summary : India’s “Nutrition Transition” and the Rise of Junk Food

GS-2 Mains : Health

Revision Notes 

Question : Evaluate the effectiveness of government initiatives such as Eat Right India, Fit India Movement, and PM Poshan 2.0 in combating the rise of junk food consumption in India.

Introduction

• India is experiencing a major dietary shift away from traditional, high-fiber diets towards processed, high-calorie Western-style diets.
• This coincides with rapid economic growth, urbanization, and a surge in junk food consumption.

The Problem with Junk Food

• Junk food is low in nutrients but high in calories, fat, salt, sugar, and preservatives.
• Scientific evidence links junk food to weakened immunity, high blood pressure, blood sugar spikes, weight gain, and increased cancer risk.
• A 2023 ICMR study found alarming rates of metabolic disorders in India: 11% diabetes, 35% hypertension, and 40% abdominal obesity.

Government Initiatives

• The Supreme Court (2013) ruled that unhealthy food poses a danger to the right to life guaranteed by the Constitution.
• Government initiatives promote healthy eating and lifestyles: Eat Right India, Fit India Movement, PM Poshan 2.0.
• FSSAI (2020) restricts junk food sales near schools.
• National Commission for Protection of Child Rights recently challenged misleading advertising of sugary “health drinks.”

Recommendations

• Protect children from junk food’s harmful effects.
• Implement clear Front-of-Pack Labelling (FOPL) for informed consumer choices.
• Provide subsidies for healthy foods (whole foods, millets, fruits, vegetables) to improve affordability and accessibility.
• Launch behavioral change campaigns targeting children and young adults to promote healthy eating habits.

Conclusion

• A public movement (“Jan Andolan”) for healthy diets is crucial to address India’s nutrition challenges.