Which of the following illnesses is caused by a virus?

Measles is the illness caused by a virus, specifically the measles virus. It is highly contagious and primarily spreads through direct contact with infectious respiratory droplets. Measles is characterized by symptoms such as high fever, cough, runny nose, and a distinctive rash that usually appears a few days after the initial symptoms.

Understanding the nature of measles as a viral infection is crucial in recognizing its treatment and prevention strategies, which mainly involve vaccination. Vaccination has significantly reduced the incidence of measles worldwide.

The other illnesses listed have different etiologies; for instance, strep throat is caused by bacteria (Streptococcus), food poisoning can be caused by various bacteria or toxins, and tetanus is caused by the toxin produced by the bacterium Clostridium tetani. This differentiation is important in the field of healthcare, as it influences both treatment approaches and public health strategies.