The following disease is caused by a virus :

Question

Accepted Answer

Measles is the correct answer because it is a disease caused by a virus. Specifically, measles is caused by the measles virus, which is a highly contagious virus that spreads through respiratory droplets. The virus infects the respiratory tract and then spreads throughout the body, leading to symptoms such as fever, cough, runny nose, inflamed eyes, and a characteristic red rash. Vaccination is the most effective way to prevent measles, and the measles vaccine is part of the MMR (measles, mumps, and rubella) vaccine.

Now, let's explain why the other options are incorrect:

1. **Diphtheria**: This disease is caused by the bacterium *Corynebacterium diphtheriae*. It affects the mucous membranes of the throat and nose and can lead to severe respiratory issues. Since diphtheria is bacterial, it is not caused by a virus.

2. **Pertussis**: Also known as whooping cough, pertussis is caused by the bacterium *Bordetella pertussis*. It is characterized by severe coughing fits and is preventable through vaccination. Like diphtheria, pertussis is bacterial, not viral.

3. **Tuberculosis**: This disease is caused by the bacterium *Mycobacterium tuberculosis*. It primarily affects the lungs but can also impact other parts of the body. Tuberculosis is a bacterial infection, not a viral one.

In summary, measles is the only disease among the options listed that is caused by a virus, making Option 4 the correct answer.