DNA Viruses Flashcards
Adenovirus
Adenoviruses are nonenveloped, icosahedral viruses containing double stranded linear DNA
Most adenovirus infections multiply in the GI tract, can be found in stools and are asymptomatic. Most individuals have been infected by several different types by adulthood.
Site of clinical syndrome is generally related to the mode of virus transmission. Certain types are more commonly associated with disease; primarily they are transmitted via the respiratory tract.
Less commonly ocular infections are transmitted by direct inoculation of the eye by virus-contaminated hands or by swimming; there are also pathological GI tract infections.
Occurs in children both sporadically and in outbreaks, often within family groups or in groups using the same swimming facility
The most common pathological manifestation is acute febrile pharyngitis, characterized by a cough, sore throat, nasal congestion, and fever, indistinguishable from other common viral respiratory infections.
Some adenovirus additionally produce conjunctivitis, in which case the syndrome is referred to as pharyngoconjunctival fever. A similar follicular conjunctivitis may occur as a separate disease.
Attachment to a host cell receptor occurs via knobs on the tips of the viral fibers, which is followed by entry into the cell by receptor-mediated endocytosis. The viral genome is then progressively uncoated while it is transported to the nucleus, where all transcription of viral genes, genome replication, and assembly occurs.
Adenoviruses all replicate well in epithelial cells. The observed disease symptoms are related primarily to the killing of these cells, and systemic infections are rare.
Parovirus 19
Single-stranded
Non-enveloped
Among the smallest DNA viruses.
It is the classic cause of the rash called fifth disease which generally occurs between 6 and 10. It is so named because it was the fifth most common cause of a pink-red infection associated rash
It also causes amaemia in immunocompromised patients
