Which test is done to detect Typhoid disease?

Raj. CHO -2020

Applied Microbiology & Infection control

Easy

Appeared in: Raj. CHO -2020

Explanation

The Widal test is a serological agglutination test used to diagnose enteric fever (typhoid).
It detects the presence of specific antibodies (O and H agglutinins) that the body produces in response to the Salmonella enterica serotype Typhi bacteria.
The test becomes positive after the first week of illness, making it a key diagnostic tool in the second week and beyond.
A rising antibody titer in paired samples taken 7-10 days apart provides a more definitive diagnosis than a single test.

Option B: This is not a recognized diagnostic test for any infectious disease. The name 'Millard' is associated with a surgical technique for cleft lip repair, not a laboratory test.
Option C: The Kahn test is a historical flocculation test used for the diagnosis of syphilis, caused by the bacterium Treponema pallidum.
Option D: The Mantoux test, or tuberculin skin test (TST), is a screening tool used to determine if a person has been exposed to Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB).

Visual 1: Infographic: Timeline of Diagnostic Tests for Typhoid Fever. This would show a timeline from Week 1 to Week 4, indicating the optimal test for each period (Blood Culture, Widal Test, Stool/Urine Culture).
Visual 2: Diagram: Widal Test Principle. This would illustrate how antibodies (agglutinins) in the patient's serum cause the bacterial antigens (O and H) to clump or agglutinate, indicating a positive result.

Clinical Relevance

Nursing practice connection: Knowing Diagnostic tests for infectious diseases, specifically Typhoid fever helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
While the Widal test is widely used, especially in resource-limited settings, its interpretation requires caution due to potential false positives (from prior vaccination or other infections) and false negatives (if tested too early).
The gold standard for diagnosing typhoid fever, especially in the first week of illness, is a blood culture. Nurses should ensure blood samples are collected before starting antibiotic therapy to maximize the yield.
What if? If a patient presents in the first 5 days of a high-fever illness, the Widal test is likely to be negative. The priority nursing action would be to obtain orders and collect a blood sample for culture, as this is the most sensitive test during the early bacteremic phase.

How to Approach the Question

First, identify the key disease in the question: 'Typhoid disease'.
Next, scan the options, which are all names of diagnostic tests.
The question is a direct recall of knowledge, asking you to match the disease with its specific diagnostic test.
Recall or deduce the purpose of each test. The Widal test is classically associated with typhoid.
Eliminate the other options by recalling their purposes: Kahn test for syphilis and Mantoux test for tuberculosis. Millard's test is an unfamiliar term in diagnostics, making it a likely distractor.

Concept Tested & Keywords

Concept Tested: Diagnostic tests for infectious diseases, specifically Typhoid fever.
Stem keywords: test, detect, Typhoid disease
Lead-in keywords: Which
Negative lead-in flag: false

QgSQnBQLX4bb_NxVST28-j