K 39 antigen is used in diagnosis of:: (A) Malaria, (B) Typhus fever, (C) Kala azar, (D) Enteric fever
Answer is C. Rapid Diagnostic Test: Now a rapid dipstick test based on the recombinant K39 protein is available for rapid diagnosis of kala-azar. K39 is an epitope apparently conserved on amastigotes of Leishmania species that cause visceral infection; by use of laboratory ELISA testing, circulating anti-K39, IgG is detectable in 95%- 100% of patients who have kala-azar, irrespective of geographic region. Ref: