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Flashcards in Parvovirus Deck (21)
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1
Q

What 2 genuses are part of the family parvoviridae?

A

Parvovirus and Dependovirus

2
Q

<p>

| The genus dependovirus requires what for replication?</p>

A

<p>

| A helper virus. Everyone should love Mare.</p>

3
Q

Parvoviridae viruses are what kind of viruses?

A

Linear, single-stranded DNA viruses

4
Q

What kind of capsid do parvoviridae viruses have? Enveloped or not?

A

Icosahedral capsid. No envelope.

5
Q

T or F. In the family parvoviridae, an equal number of progeny contain either positive or negative strands.

A

T

6
Q

Where does replication and assembly occur for parvoviridae viruses? What kind of cells do they replicate in?

A

In the nucleus. Rapidly dividing cells (thus providing replication function).

7
Q

What dz does parvo B19 cause?

A

Erythema infectiosum: a mild, common childhood rash.

8
Q

What percentage of the adult population is seropositive for parvo B19?

A

50%. Conversion usually occurs after school age is attained. Ab’s provide protective immunity.

9
Q

How is parvo B19 spread?

A

Direct contact with respiratory secretions that occurs prior to the rash.

10
Q

What are the 2 phases of parvo B19 infection?

A
  1. Initial viremia presents with FLS
  2. Second phase is when rash may occur
    Notes: symptoms are immune-mediated and 4/5 will show symptoms.
11
Q

What is the other name for erythema infectiosum?

A

Fifths dz.

12
Q

What is the characteristic rash of Fifths Dz?

A

“slapped cheek” rash. Also lacy red rash on trunk and limbs.

13
Q

What is the usual course of fifths dz?

A

Resolves in 7-10 days.

14
Q

What is the adult presentation of fifths dz?

A

Joint pain or swelling (polyarthritis) along with FLS. Adults tend to have less rash.

15
Q

What can parvo B19 cause in sickle cell pts?

A

Transient aplastic crisis.

16
Q

How does parvo B19 cause a transient aplastic crisis in sickle cell pts?

A

B19 infects and lyses erythroid precursor cells resulting in loss of RBC production during infxn (7-10 days). Sickle cell pts cannot tolerate abscence of precursor pool resulting in severe anemia.

17
Q

ICP pts develop what with parvo B19 infection?

A

Chronic anemia

18
Q

Parvo B19 can be transmitted placentally. What is the consequence of this?

A

Most infxns are of no concern. However, 5% of infxns can result in severe fetal anemia, hydrops fetalis, or miscarriage. These are most common during the first half of pregnancy.

19
Q

How is dx of parvo B19 made?

A

Most often made by appearance of rash. Serologic and viral DNA testing of blood sample if necessary.

20
Q

What dz is fifths dz sometimes confused with?

A

Rubella

21
Q

What is the tx for fifths dz?

A

Treat the FLS and the itchy rash. Anemia pts may require a blood transfusion. Difficult to prevent b/c infectious period occurs prior to rash. There is no vaccine. General hygiene practices may limit spread.