These profiles reflect a vigorous IgM response attended by production of low avidity IgG and variously accompanied by rising IgG and/or viremia, which is consistent with responses to primary infection by hitherto immunologically naı¨ve individuals. The acute marker profiles of 9 other patients (case 1 to 9) feature rising IgG anti-HEV levels attended by production of avid IgG anti-HEV, but all yielded a false negative finding for IgM anti-HEV and all, except one (case 9), tested negative for HEV RNA also. Similarly as previously reported cases,[6,7] such profiles are consistent with anamnestic responses to reinfection by immune subjects.