Kalmar "zazzabin jini" na nufin rukunin cututtuka da ƙwayoyin cuta daban-daban ke haifar da su waɗanda ke haifar da zubar jini da zazzabi. Zazzaɓin ciwon jini yana faruwa ne da zazzaɓi kwatsam, ciwon kai, ciwon gabobi da tsoka, tashin zuciya da amai, gajiya, da zubar jini daga sassa daban-daban na jiki kamar gumi, hanci, da gabobin ciki. Ana kamuwa da waɗannan ƙwayoyin cuta ga mutane ta hanyar hulɗa da dabbobi masu kamuwa da cuta, kamar su rodents ko primates, ko kuma ta hanyar saduwa da ruwan jikin masu kamuwa da cuta. Wasu sanannun misalan ƙwayoyin cutar zazzabin jini sun haɗa da cutar Ebola, cutar Lassa, da cutar Dengue. Mummunan zazzabin hemorrhagic na iya bambanta daga mai sauƙi zuwa mai tsanani, tare da wasu nau'ikan ƙwayoyin cuta na iya yin kisa.