Virus vs. Bacteria: The Disease List

The CGL Trap:
"Typhoid is caused by a virus." (FALSE).
"Common Cold is caused by bacteria." (FALSE).
In exams, confusing the "Causative Agent" is the easiest way to lose 2 marks.

To crack Biology in SSC CGL, you don't need to be a doctor. You just need to know who the villain is: Is it a Virus, a Bacteria, or a Protozoa?

[Image of diagram comparing structure of virus and bacteria]

1. The Villain Gallery

Here is the definitive categorization. Memorize this table.

VIRUS

(Non-living outside host, Living inside)

• Common Cold (Rhinovirus)
• Dengue (Arbo virus)
• Polio
• Rabies (Hydrophobia)
• Chicken Pox
• HIV / AIDS
• Measles

BACTERIA

(Single-celled living organisms)

• Typhoid (Salmonella typhi)
• Tuberculosis (TB)
• Cholera
• Tetanus (Lockjaw)
• Plague
• Pneumonia
• Leprosy

PROTOZOA

(Parasites usually spread by vectors)

• Malaria (Plasmodium)
• Kala-azar (Black Fever)
• Sleeping Sickness
• Pyorrhea (Gum bleeding)

2. The "Vector" Confusion (Mosquitoes)

Not all mosquitoes are the same. In CGL, they will ask you specifically which mosquito carries which disease.

[Image of life cycle of malarial parasite in mosquito and human]

🦟 Who Bites Who?

• Female Anopheles: Spreads Malaria. (Note: Only the *female* bites because she needs blood for eggs).
• Aedes Aegypti: Spreads Dengue, Chikungunya, and Zika. (Often called the "Tiger Mosquito" due to stripes).
• Culex: Spreads Filaria (Elephantiasis).
• Tsetse Fly: Spreads Sleeping Sickness (Protozoan).
• Sand Fly: Spreads Kala-azar.

3. High-Yield Facts for CGL

• Widal Test: This diagnostic test is used specifically for Typhoid.
• BCG Vaccine: Given to infants to protect against Tuberculosis (TB).
• DOTS: The government treatment strategy for TB.
• Quinine: The drug used to cure Malaria, extracted from the bark of the Cinchona tree.
• Antibiotics: Work against Bacteria, but DO NOT work against Viruses.

---

Revision Flashcards

Typhoid

Virus or Bacteria?

Bacteria

(Salmonella typhi). It is water-borne, not air-borne.

Dengue Vector

Which mosquito spreads it?

Aedes Aegypti

Also spreads Chikungunya. It breeds in clean water.

Hydrophobia

Associated with which disease?

Rabies

Caused by a virus from dog/animal bites. Patient develops a fear of water.

Kala-azar

Caused by what?

Protozoa

(Leishmania). It is spread by the Sand Fly.

Exam-Style MCQs

Q1. Which of the following is NOT a viral disease?

A) Dengue

B) Polio

C) Plague

Correct! Plague is Bacterial (Yersinia pestis). Dengue and Polio are Viral.

Q2. The Widal Test is used for the diagnosis of:

A) Malaria

B) Typhoid

Correct! A very common question in CGL.

C) Cholera

Q3. "Lockjaw" is another name for which disease?

A) Tetanus

Correct! It causes muscle spasms, locking the jaw.

B) Rabies

C) Tuberculosis

Part of the CGL Biology Series.