Small/Medium DNA viruses Flashcards
What are the Enveloped DNA viruses?
Pox, Herpes and Hepadna
What are the Naked capsid DNA viruses?
Polyoma, Papilloma, Adeno, Parvo
Describe Adenoviridae genome structure.
Double stranded linear DNA, icosahedron capsis
Discuss Adenovirus Replication
- Entry via receptor mediated endocytosis
2. Early genes are transcribed and translated using host cell proteins.
What is the role of the early genes?
- Activate viral gene expression
- Viral DNA replication
- induce host cell to S phase
- Inhibit interferon response.
What is the role of the late genes?
- Structural proteins of virus
2. Targeted to nucleus for assembly of virions.
What are the symptoms of adenovirus infection?
Conjunctivitis, gastroenteritis
Where can adenoviruses establish lytic and latent infections?
Lytic: Mucoepithelial cells in Resp/GI tract and conjunctiva
Latent/Persistent: Lymphoid tissue
What is the adenovirus stable to? How is it spread?
Stable to drying, detergents and GI secretions. Spread by aerosol, contact or fecal-oral route.
What condition must a cell be in to be infected by a Parvovirus?
It can only infect mitotically acitve cells because they need their enzymes.
Discuss Erythema Infectiousum
Replication in respiratory tract then in bone marrow; kills erythroid precursor cells
When is Erythema Infectiousum contagious?
When its in the bone marrow; Released into oral and respiratory secretions
When is Erythema infectiousum cleared?
With the appearance of antibody; Complexes precipitate in skin and joints. No longer contagious
What are the symptoms for Erythema infectiousum?
Fever, headache, chills
What are two complications of Parvovirus?
- Can cause aplastic crisis in patients with hemoltyic anemia.
- Replicates in fetal erythroid cells; hydrops fetalis
