 "Mycobacterium szulgai" and "Yersinia" and "Toxoplasma" species have been implicated.More recently, growing evidence suggests a role for Epstein-Barr virus, as well as other viruses (HHV6, HHV8, parvovirus B19, HIV and HTLV-1) in the pathogenesis of KFD.However, many independent studies have failed to identify the presence of these infectious agents in cases of Kikuchi lymphadenopathy.