Tonsillitis is a bacterial infection, caused by streptococcus, and glandular fever or infectious mononucleosis is a viral illness due to Epsein-Barr virus.Both produce sore throat, both may give rise to pus on the tonsils, though the exudate from 'mono' is usually white rather than yellow.f it hurts near your ears/nose/throat/underarms, it's glandular fever. If it just hurts in your throat its tonsilitis. (basically) Glandular fever effects all of your glands which are found in the places mentioned before and tonsilitis only effects your tonsils and throat.