Over the last 20 years, I have found this phenomenon extremely common with IHA blood test for amoebiasis. It is important to note that in the absence of demonstration of amoeba from the liver, only a positive blood test like IHA can diagnose the swelling in the liver to be amoebic. IHA is a most sensitive test and is always positive. Unfortunately it is not specific. Fluorescence test for amoebiasis and counter immunoelectrophoresis tests are more specific for the diagnosis.

This might explain that why I have seen a number of cases having a very high title and a positive IHA test for amoebiasis whilst these patients were investigated for fever etc. and did not have any amoebic pathology in the liver or elsewhere.

In fact the anamnestic reaction of IHA is so common that the highest titre like 1 in 10,000 to 20,000 I have seen in patients who never had any amoebiasis in the liver or elsewhere.

In conclusion a positive blood IHA test for amoebiasis should be given importance to only in a patient who has a space occupying lesion in the liver.