Question

Give an account of some important viral diseases of human beings.

Answer 1

Some important viral diseases of humans are - Hepatitis, Polio, Rabies and AIDS.

1. Hepatitis -
Causal organism - Hepatitis virus
Mainly affects liver and usually results in jaundice.
There are different types of hepatitis - hepatitis A, hepatitis B, hepatitis C, hepatitis D, hepatitis E.

Mode of transmission -

• Hepatitis A - spreads through contaminated food and water.
• Hepatitis B - spreads through contact with infected person's secretions such as saliva, sweat, tears etc.

Symptoms -

• Fever
• Nausea and vomiting
• Jaundice
• Dark yellow urine
• Itching of skin

Prevention -

• Eating hygenic food and drinking disinfected water
• Immunisation with hepatitis B and hepatitis A vaccines
• Use of disposable syringes
• Proper cleaning of hands after handling bed, clothes and utensils of the pateints

2. Polio
Causal organism - Polio virus
Mainly affects the children

Modes of transmission -

• Spreads through faecal-oral route

Symptoms -

• Headache and fever
• Stiffness of the neck and convulsions
• Paralysis of limbs due to damage of motor nerve cells in the spinal cord
• Respiratory failure

Prevention -

• Immunization with oral polio vaccine

3. Rabies
Causal organism - Rabies virus named Lyssavirus.

Modes of transmission -

• Spreads through the bite of an infected animal such as dogs or cats.

Symptoms -

• Severe headache and high fever
• Painful contractions of muscles of throat and chest
• Hydrophobia, where an individual is afraid of water

Prevention -

• Vaccination of pet dogs and cats
• Cleaning the wound with soap and clean running water

4. AIDS -
Affects the immune system of the body

Causal organism - Human Immuno Virus (HIV)

Modes of Transmission -

• By sharing infected needles while injecting drugs.
• By having sexual contact with an infected person.
• From an infected mother to the child through pregnancy or breast feeding.

Symptoms -

• Weight loss
• Prolonged fever
• Prolonged diarrhoea
• Kaposi’s sarcoma
• Meningitis
• Complete loss of immunity with infections like tuberculosis and pneumonia, etc.

Prevention -

• Education about the disease
• Use of disposable needles and syringes
• Avoiding sharing of razors for shaving
• Protected sexual intercourse using condoms