<prompt> In a case of Kala-azar aldehyde test becomes positive after2 weeks4 weeks8 weeks12 weeks  <response>: 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 