Consider the following diseases : 1. Diphtheria 2. Chickenpox 3. Smallpox Which of the above diseases has/have been eradicated in India ?
Contents10
- A1 and 2 only
- B3 only
- C1, 2 and 3
- DNone
Show answer
Answer: (B) 3 only
Only Smallpox has been eradicated — both in India (1977) and globally (declared by WHO in 1980).
It remains the ONLY human disease ever fully eradicated worldwide.
Diphtheria — NOT eradicated.
- It still occurs in India, though vaccination (DPT vaccine) has reduced it significantly.
- Cases resurge when vaccination coverage drops.
Chickenpox (Varicella) — NOT eradicated.
- It still occurs commonly in India.
- There is a vaccine, but it's not part of India's Universal Immunisation Programme.
Key distinction:
- Eradicated = zero cases worldwide, permanently.
- Eliminated = zero cases in a specific country/region.
- Controlled = reduced but still present.
In India, Polio was eliminated (2014), but smallpox is the only disease eradicated.
Smallpox is the only human disease ever completely eradicated worldwide, with India's last case in 1977 and WHO declaring global eradication in 1980.
The question tests the critical difference between eradication (zero cases globally forever), elimination (zero cases in one country), and control (reduced cases but still present).
Smallpox Eradication
Science And Technology Smallpox eradicated
Smallpox Eradication: The Only Success Story
Smallpox is the only human disease ever completely eradicated worldwide
Last natural case in India: 1975, globally: 1977
WHO declared global eradication in 1980
Achieved through intensive vaccination and surveillance
Smallpox was a deadly viral disease that killed millions throughout history. Its eradication represents humanity's greatest public health achievement — the first and only infectious disease eliminated from nature through human effort.
Why Smallpox Could Be Eradicated
No animal reservoir — virus only survived in humans
Visible symptoms — easy to identify and isolate cases
Effective vaccine — provided lifelong immunity
Global political will — WHO-led coordinated campaign
Ring vaccination strategy — vaccinated contacts of infected persons
Eradication Timeline
%%{init: {"flowchart": {"wrappingWidth": 460}}}%%
flowchart TD
s1["`**1958**
WHO launches global eradication program`"]
s2["`**1967**
Intensified eradication campaign begins`"]
s3["`**1975**
Last case in India (Rahima Banu in Bangladesh border)`"]
s4["`**1977**
Last natural case globally (Somalia)`"]
s5["`**1980**
WHO declares global eradication`"]
s1 --> s2
s2 --> s3
s3 --> s4
s4 --> s5This PYQ tests whether students confuse eradication with elimination or control. Only smallpox qualifies as eradicated — meaning zero cases exist anywhere on Earth.
Trap: Confusing eradicated (zero cases worldwide) with eliminated (zero cases in one country)
Trap: Thinking multiple diseases have been eradicated — only smallpox has achieved this
Trap: Confusing India's last case (1975) with global declaration date (1980)
Diphtheria in India
Science And Technology Diphtheria
Diphtheria: Controlled but Not Eradicated
Diphtheria is NOT eradicated in India — cases still occur
Prevented by DPT vaccine in Universal Immunisation Programme
Cases resurge when vaccination coverage drops
Diphtheria is a bacterial infection affecting the throat and respiratory system. While vaccination has dramatically reduced cases in India, the disease has not been eradicated — it still occurs, especially in areas with poor vaccination coverage.
Current Status
Cases still reported — sporadic outbreaks in various states
DPT vaccine provides protection (Diphtheria, Pertussis, Tetanus)
Part of UIP — given at 6, 10, 14 weeks with boosters
Herd immunity critical — disease returns when coverage falls below threshold
Trap: Assuming vaccination success means eradication — diphtheria is controlled, not eradicated
Trap: Confusing elimination goals with actual eradication status
Chickenpox in India
Science And Technology Chickenpox
Chickenpox: Common and Not Eradicated
Chickenpox is NOT eradicated — still occurs commonly in India
Varicella vaccine exists but not in Universal Immunisation Programme
Most children get infected naturally, developing lifelong immunity
Chickenpox (Varicella) is a highly contagious viral disease common in Indian children. Despite an effective vaccine being available, it remains widespread because vaccination is not part of India's routine immunization schedule.
Why Still Common
Vaccine not in UIP — available privately but not universally given
Highly contagious — spreads easily through respiratory droplets
Mild in children — most recover without complications
Natural infection common — provides lifelong immunity after recovery
Trap: Thinking vaccine availability means eradication — chickenpox vaccine exists but disease remains common
Trap: Assuming all vaccine-preventable diseases are eradicated in India
Eradication vs Elimination vs Control
Science And Technology
Disease Eradication Terminology: Critical UPSC Distinctions
Eradicated = zero cases worldwide, permanently
Eliminated = zero cases in specific country/region
Controlled = reduced cases but still present
Key Distinctions
Term | Meaning | Scope | India Example |
|---|---|---|---|
Eradicated | Zero cases exist anywhere | Global | Smallpox (1980) |
Eliminated | Zero cases in specific area | Country/Region | Polio (2014) |
Controlled | Cases reduced significantly | Variable | Diphtheria, TB |
Endemic | Regularly present in population | Country/Region | Malaria, Dengue |
India's Disease Status
Only eradicated disease: Smallpox (globally eradicated)
Eliminated diseases: Polio (India declared polio-free in 2014)
Controlled diseases: Diphtheria, Pertussis, Measles (reduced but not eliminated)
Endemic diseases: Malaria, Dengue, Chikungunya (regularly occurring)
Major Trap: Using eradicated and eliminated interchangeably — they have precise different meanings
Trap: Assuming vaccination success automatically means eradication
Trap: Confusing polio elimination in India with global eradication (polio not globally eradicated yet)