Human Health And Disease

Question

A patient diagnosed positive by the Widal test shows persistent high fever with intestinal infection, which bacterium is the causative agent?

RankGuru · Accepted Answer

Typhoid fever is a bacterial disease caused by Salmonella typhi, and its confirmatory laboratory diagnosis classically relies on the Widal test, which detects rising antibody titres against the pathogen in the patient's serum. The bacterium enters the body through contaminated food and water, reaches the small intestine, and then migrates through the intestinal wall into other organs via the bloodstream, producing sustained high fever, weakness, stomach pain, and constipation. Streptococcus pneumoniae causes pneumonia, an infection of the alveoli of the lungs, and is not diagnosed by the Widal test, so it is incorrect. Haemophilus influenzae is another respiratory pathogen causing pneumonia and is unrelated to typhoid diagnosis. Wuchereria bancrofti is not even a bacterium; it is a filarial worm causing elephantiasis, making it clearly wrong. As stated in NCERT Class 12, Chapter 8 (Human Health and Disease), the historic case of Mary Mallon (Typhoid Mary) illustrated how a carrier could spread Salmonella typhi. As a sanity check, only Salmonella typhi simultaneously matches a bacterial intestinal infection and a positive Widal test, confirming it as the correct causative organism among the options provided.

Human Health And Disease

Select the correct option:

🔒 Solution Hidden from View

More biology and human welfare Practice Questions

Normal cells stop dividing once they touch neighbouring cells, but cancer cells continue multiplying...

The human immunodeficiency virus causing AIDS stores its genetic information as RNA, which enzyme en...

Which protozoan parasite transmitted by the female Anopheles mosquito is responsible for the most le...

Microbes grown on a large scale as an alternative protein-rich source of food for animals and humans...

A wheat variety developed through plant breeding to combat protein malnutrition by improving grain p...

The capacity of a single plant cell to regenerate into a complete plant, exploited during micropropa...

When isolated protoplasts of two different plant varieties are fused to create a hybrid such as the ...

Which controlled breeding technique allows a superior cow to yield several calves yearly by transfer...

For large-scale commercial production of honey and beeswax through apiculture, which species of hone...

A bacterium widely used as a biological insecticide produces protein crystals that specifically kill...

In paddy fields, which free-living photosynthetic cyanobacterium serves as an important biofertilize...

The combustible gas produced in a biogas plant from cattle dung is generated mainly through the meta...

About This Question

Solution