7.pox virus Flashcards
What is the genome type of Poxviridae?
Double-stranded DNA (dsDNA), linear.
What is the structure of Poxviridae?
Enveloped virus with complex morphology, brick-shaped.
Which viruses are part of Orthopoxviridae?
Variola (smallpox), Vaccinia, Cowpox, Monkeypox, Molluscum contagiosum.
What is unique about Poxviridae replication?
It contains its own DNA-dependent RNA polymerase (DDRP) and replicates in the cytoplasm.
What is the largest virus?
Poxviridae (250 nm), visible under light microscopy.
What type of infections are caused by Poxviridae?
Generalized and localized infections.
How is Variola (smallpox) transmitted?
Respiratory droplets and direct contact.
What is the incubation period for Variola?
7–14 days.
What are the two stages of viremia in Variola?
Primary viremia (transient) and secondary viremia (causes exanthem skin rash and eruptions).
Where does the Variola rash start, and how does it spread?
Starts on the face, spreads centrifugally, and is synchronous.
How is Variola diagnosed?
Clinical appearance, lab tests on crusts using electron microscopy (E.M.), serology, and culture.
What was the main prevention method for smallpox?
Live attenuated vaccine, with smallpox eradication stopping vaccination in 1980.
How is Molluscum contagiosum transmitted?
Close contact (e.g., STD) and common in children.
What do Molluscum contagiosum lesions look like?
Small, pink, cup-shaped papules with a central dimple (umbilicated appearance).
How is Molluscum contagiosum treated?
Curettage or liquid nitrogen; no specific vaccine or Rx.
