Paramyxoviruses Flashcards Preview

Pulmonary Micro > Paramyxoviruses > Flashcards

Flashcards in Paramyxoviruses Deck (27):
1

What are the characteristics of all 3 viruses?

1. Enveloped, non segmented (no reassortment), and negative RNA
2. Tropism restricts entry to respiratory tract cells, thus no systemic infxns

2

What are the virulence factors?

Fusion protein, G, and HN

3

What does fusion protein (F) do?

Viral entry/fusion to adjacent cells -> syncytia

4

What does G do?

Unknown gp where RSV binds; RSV can also bind nuclein

5

What does HN do?

hMNV + hPIV bind here

6

What is the mechanism of disease?

Virus infects airway epithelium and upper resp. tract, it then spreads to the lower reps. tract via dendritic cells. This causes sloughing of epithelium, excessive mucin production, and interstitial lung infiltrates

7

What's the epidemiology of RSV?

#1 cause of lower RT illness/pneumo in kids

8

What's the epidemiology of hMPV?

#2 cause of lower RT illness in kids

9

What's the epidemiology of hPIV?

#2 cause of pneumonia in kids. And it's common in elderly/immunocompromised

10

What is common among all three viruses transmission?

All transmit person-person via large droplets. Very seasonal (fall/spring); and they have community emergence (not widespread like flu)

11

What diseases are associated with RSV?

RSV is the #1 cause of bronchiolotis and pneumonia in less than 1 yr old infants. The infection is also common in adults but it known more for children.

12

Where does RSV infect in the body?

RSV infects nasopharynx, which leads to a LRT. The LRTs can be permanent (chronic lung disease or asthma)

13

What are the predisposing factors to RSV infxn?

Prematurity, early infxn ( in infants less than 3mo), lung/heart disease, SCID, and low oxygen supply

14

What is the presentation of RSV?

Begins with URT symptoms -> LRT symptoms in 2 days

15

How do you make the Dx of RSV?

Culture from URT, ELISA for Antigen, RT-PCR

16

How do you Tx RSV?

No vaccine. Care is supportive (FiO2, fluids, bronchodilator).
1. Palvizumab: Ab for RSV ( decrease viral loads so it's not as severe)
2. Ribavirin: nucleoside analog interferes with viral replication

17

What disease is caused by hMPV?

Bronchiolitis and +/- pneumonia in infants/elderly

18

How does hMPV present?

Similar to RSV but also may see myalgia

19

How do you Dx hMPV?

RT-PCT is best (Serological is bad; most kids are positive by 10yrs)

20

How do you tx hMPV?

No vaccine; give supportive care

21

What disease does hPIV cause?

hPIV2 is #2 cause of pneumonia and bronchiolitis in kids.

22

How does hPIV present?

Croup, hoarseness, and systemic symptoms

23

What's the Dx of hPIV?

culture, RT-PCR, ELISA, or high IgG/IgM

24

What's the Tx for hPIV?

No vaccine, supportive care

25

What protein facilitates syncytium formation?

F protein

26

What do you see on CXR?

Hyperinflated lungs, atelectasis, interstitial disease (not specific)

27

What are the two most important things to ID these viruses?

1. Age of pt (kids)
2. Season (late fall/early spring)