A person complaining of stomach ache, weakness and sustained high fever was recommended Widal test by the doctor. Identify the pathogen responsible for the disease the person is suffering from:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Salmonella typhi
The Widal test confirms typhoid fever. Sustained high fever, weakness and stomach pain are its common symptoms.
Option (1) Streptococcus pneumoniae — Incorrect. This bacterium causes pneumonia, which infects the alveoli of the lungs. Its signs are fever, cough and difficulty in breathing.
Option (2) Rhino Virus — Incorrect. Rhinoviruses cause the common cold. It affects the nose and the respiratory passage, not the intestine.
Option (3) Salmonella typhi — Correct. This bacterium causes typhoid fever. It enters the small intestine through contaminated food and water and spreads to other organs through the blood.
Option (4) Plasmodium vivax — Incorrect. This protozoan causes malaria, where chill and high fever come back every three to four days.
NCERT Extract:
Common Diseases in Humans – “… Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings. These pathogens generally enter the small intestine through food and water contaminated with them and migrate to other organs through blood. Sustained high fever (39° to 40°C), weakness, stomach pain, constipation, headache and loss of appetite are some of the common symptoms of this disease. Intestinal perforation and death may occur in severe cases. Typhoid fever could be confirmed by Widal test : A classic case in medicine, that of Mary Mallon nicknamed Typhoid Mary, is worth mentioning here.”