Which test is used to detect typhoid?

NHM UP Staff Nurse - 2017

Microbiology

Easy

Appeared in: NHM UP Staff Nurse - 2017

Explanation

The Widal test is a classic serological assay used for the diagnosis of typhoid fever.
It detects agglutinating antibodies in the patient's serum against the O (somatic) and H (flagellar) antigens of the bacterium Salmonella typhi.
The test becomes positive in the second week of infection, and a rising antibody titer is more diagnostically significant than a single test.
While widely used, it is important to note that blood culture is the gold standard for diagnosis, especially in the first week of illness.

Option B: The 'Millard test' is not a recognized diagnostic test for any infectious disease. This term likely refers to the Millard rotation-advancement procedure, which is a common surgical technique used to repair a cleft lip.
Option C: The Kahn test is a historical flocculation test used for the diagnosis of syphilis. It detects antibodies against Treponema pallidum.
Option D: The Rorschach test, or inkblot test, is a projective psychological test. It is used by psychologists to assess a person's personality characteristics and emotional functioning.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Diagnostic test for Typhoid Fever as background academic context rather than a clinical decision trigger.
A key nursing responsibility is understanding the timing of diagnostic tests. For a patient with suspected typhoid in the first week of fever, the nurse should anticipate an order for a blood culture, as the Widal test will likely be negative.
Patient education is crucial. Nurses should be able to explain to patients and families that while the Widal test is common, it is not always definitive and results must be correlated with clinical findings.
What if? If a patient with fever presents in the third week of illness and has a negative blood culture, a Widal test showing a high or rising titer for O and H antigens would become a more valuable piece of diagnostic evidence.

How to Approach the Question

First, identify the key disease in the question stem, which is 'typhoid'.
Next, recall or look for the specific diagnostic test associated with this disease among the options.
Evaluate each option. The Widal test is specifically linked to typhoid diagnosis.
Eliminate the other options by identifying what they are used for. The Kahn test is for syphilis, and the Rorschach test is for psychological assessment.
Recognize that 'Millard test' is an outlier, likely referring to a surgical procedure, making it an incorrect choice for diagnosing an infection.
Confirm the selection of the Widal test as the most appropriate answer for diagnosing typhoid among the given choices.

Concept Tested & Keywords

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