Adenovirus

They commonly cause upper and lower respiratory infections, gastroenteritis and conjunctivitis. Morphologically they have icosahedral symmetry of capsid with rod-like projections ending in knob-like structures which are important for attachment to the host surface (similar to bacterial pili, remember ?). These projections are hemagglutinins. Infected cells show intranuclear inclusions. As they are non enveloped, they are not killed by ether, alcohols etc. They may become latent in tonsillar tissue.

Clinical features: Most commonly they cause cold like symptoms, pharyngitis, pharyngoconjunctival fever (syndrome of fever, pharyngitis, conjunctivitis and lymphadenopathy), epidemic conjunctivitis, atypical pneumonia, acute hemorrhagic cystitis and gastroenteritis. Types 8 and 19 cause epidemic keratoconjunctivitis, types 4,7 and 21 cause respiratory disease, types 40 and 41 cause diarrhea and types 11 and 21 cause hemorrhagic cystitis.

Laboratory diagnosis of Adenovirus infections: Diagnosis is made by direct immunofluorescence of nasopharyngeal aspirates, culture on HeLa, Hep 2 cell lines, hemagglutination tests and serological tests like CFT, RIA and haemagglutination inhibition assays.