This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology (General Propeies, DNA Viruses), Subject name: Microbiology
Paul Bunnell test is done for: 
Select and explain. 
A. Malta fever, B. Leptospirosis, C. Enteric fever, D. Infectious mononucleosis
D: Infectious mononucleosis
Answer: D: Infectious mononucleosis 
Explanation: Paul Bunnell test: Paul Bunnell test is heterophile agglutination test used for diagnosis of infectious mononucleosis, which is caused by EBV (Epstein-Barr virus). These heterophilic antibodies are IgM antibodies produced in response to EBV infection, that recognize and cross react with Paul-Bunnell antigen on sheep, horse, and bovine RBCs. Therefore, serum from patients with acute mononucleosis agglutinates sheep, horse, or bovine erythrocytes. Enteric fever- diagnosed by widal test. Malta fever- diagnosed by standard agglutination test. Leptospirosis- diagnosed by Microscopic agglutination test (MAT).