Prozone like effect Index

The prozone-like (postzone) phenomenon More correctly the "prozone-like" or "postzone" phenomenon* is a very rare, but recognised effect that causes false negative results of tests. Most often the prozone-like effect is seen with HRP2 antigens. This effect means that where these is a very high parasitaemia (causing excess HRP2 antigen to be present) test can appear negative. It is thought that the presence of excess antigen means that the formation of appropriate antibody-antigen complexes is prevented so that the test does not function correctly. *Note the term postzone effect is preferred in this context as prozone refers to excess antibody, while postzone refers to excess antigen as in this case.