Question

A sewage worker presented with abdominal pain, jaundice, conjunctival injection, and blood in the urine for the past 5 days. Which of the following is the investigation of choice?

• A. Widal test
• B. Microscopic agglutination test
• C. Weil-Felix reaction
• D. Paul-Bunnell test

Answer 1

The Correct Option is B

The scenario described involves a sewage worker experiencing symptoms such as abdominal pain, jaundice, conjunctival injection, and hematuria (blood in urine). These symptoms are suggestive of an infection potentially caused by Leptospira species, commonly associated with leptospirosis, a bacterial infection often seen in individuals working in environments exposed to water contaminated with animal urine.

To confirm leptospirosis, the investigation of choice is the Microscopic Agglutination Test (MAT). This test is the gold standard for diagnosing leptospirosis and involves mixing the patient's serum with live antigens of Leptospira serovars to detect agglutination, which indicates the presence of specific antibodies.

A review of the options highlights the following:

Test	Purpose
Widal test	Used for diagnosing typhoid fever.
Microscopic agglutination test	Used for diagnosing leptospirosis.
Weil-Felix reaction	Used for diagnosing rickettsial infections.
Paul-Bunnell test	Used for diagnosing infectious mononucleosis.

Given this analysis, the most appropriate choice for investigating this patient's condition, suspected to be leptospirosis, is the Microscopic Agglutination Test.