links between other infections and gbs are less certain. two other herpesviruses (epstein–barr virus/hhv-4 and varicella zoster virus/hhv-3) and the bacterium "mycoplasma pneumoniae" have been associated with gbs. the tropical viral infection dengue fever and zika virus have also been associated with episodes of gbs. previous hepatitis e virus infection has been found to be more common in people with guillain–barré syndrome.