Which of the following diseases is detected by the Widal test?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Typhoid.
The Widal test is used for the detection of Typhoid fever. This diagnostic blood test identifies the presence of specific antibodies (agglutinins) against the Salmonella typhi and Salmonella paratyphi bacteria, which cause enteric fever.
It is a serological assay that has been used for decades as a presumptive tool for diagnosing typhoid, especially in regions where the disease is endemic.
The other diseases listed—Influenza (a viral respiratory illness), Pneumonia (often bacterial or viral lung infection), and Diphtheria (a bacterial infection primarily affecting the throat and airways)—are diagnosed through different methods, such as culture, PCR, or specific antigen tests, not the Widal test.