The VDRL (venereal disease research laboratory) test is done for the diagnosis of?

UPRVUNL - 2021

Microbiology

Easy

Appeared in: UPRVUNL - 2021

Explanation

The VDRL (Venereal Disease Research Laboratory) test is a standard non-treponemal serological screening test for syphilis.
It detects IgM and IgG antibodies to cardiolipin, a lipid antigen present on the surface of the treponeme and also released from damaged host cells.
A key use of the VDRL test is to monitor disease activity and response to treatment, as the antibody titer decreases with effective therapy.
Due to the possibility of false positives, a reactive VDRL test must always be confirmed with a more specific treponemal test (e.g., FTA-ABS).

Option A: Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae. Its diagnosis relies on clinical presentation and is confirmed by culturing the organism and testing for toxin production (Elek test), not by the VDRL test.
Option B: Typhoid fever is caused by the bacterium Salmonella Typhi. The primary diagnostic methods are blood culture (especially in the first week) and the Widal test, which detects antibodies against Salmonella antigens.
Option D: Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae. It is diagnosed using Nucleic Acid Amplification Tests (NAATs), Gram staining of discharge, or culture on specific media like Thayer-Martin agar.

Clinical Relevance

Nursing practice connection: Use the key finding related to Diagnostic test for Syphilis to guide bedside assessment, documentation, and the next nursing action.
Nurses must understand that a positive VDRL is a preliminary finding, not a final diagnosis. The primary nursing action is to anticipate an order for a confirmatory treponemal test.
Patient education is critical. The nurse should be prepared to explain what a positive screening test means, the possibility of a 'false positive,' and the importance of follow-up testing without causing undue alarm.
In India, syphilis screening with VDRL/RPR is a mandatory part of antenatal care to prevent congenital syphilis, a severe and preventable condition in newborns.

How to Approach the Question

This is a factual recall question that tests your knowledge of common laboratory diagnostic tests.
Identify the key term in the question stem: 'VDRL (venereal disease research laboratory) test'.
Recall the primary disease associated with this test. The name 'Venereal Disease Research Laboratory' itself is a strong clue that it's related to a sexually transmitted infection.
Evaluate the given options: Diphtheria, Typhoid fever, Syphilis, and Gonorrhea.
Match the VDRL test to its corresponding disease, which is Syphilis.
Mentally eliminate the other options by recalling their respective diagnostic tests (e.g., Widal for Typhoid, culture for Gonorrhea).

Concept Tested & Keywords

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E6 Nelson Textbook of Pediatrics(2024) — Volume 1 pp. 1874-1876, 1258-1260

E6 Medicine Harrison 22e Part 1 p. 1474-1476