How soon after the onset of symptoms should a Clearview IM test be carried out?
It has been reported that IM heterophile antibodies are usually demonstrable one week after the onset of the illness (60-70% of adult patients), peaking at 3-4 weeks (80-90% of adults). Therefore if testing is carried out too soon then false negative results will occur which is the case for all IM heterophile antibody tests.
