This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: parasitology, Subject name: Microbiology
In a case of Kala-azar aldehyde test becomes positive after 
Select and explain. 
A. 2 weeks, B. 4 weeks, C. 8 weeks, D. 12 weeks
D: 12 weeks
Answer: D: 12 weeks 
Explanation: In the Kala-azar endemic areas of India, Napier&;s aldehyde test has been used for a long time. The test relies on the jellification caused by the binding of the serum globulins to the formaldehyde About 85 per cent of patients with disease of 3 months or more gives positive reaction.TEXTBOOK OF MEDICAL PARASITOLOGY, BAVEJA,3RD EDITION, PAGE NO 42