This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Investigation of choice for invasive amebiasis is: 
Select and explain. 
A. Indirect heamagglutination, B. ELISA, C. Counter immune electrophoresis, D. Microscopy
B: ELISA
Answer: B: ELISA 
Explanation: Answer is B (ELISA) In Extra-intestinal amebiasis, antibody detection by ELISA is the most sensitive test - Ghai 5th/221. ELISA : This test is positive in more than 90% of patients and it usually reves to normal with in 6-12 months. IHA : May also be done in invasive Amoebiasis or liver abscess. The interpretation of the IHA is however more difficult because titres may remain positive for as long as 10 years.