Viral & Prion Proteins Flashcards Preview

CP Microbiology Themes 1 & 7 (Core & advanced) > Viral & Prion Proteins > Flashcards

Flashcards in Viral & Prion Proteins Deck (25):
1

What are herpes viruses?

Double stranded enveloped DNA viruses (herpes simplex 1 &2, varicella, Epstein Barr, CMV, Human Herpes 6A & B and 7 and 8.
- characterised by ability to establish latency and reactivate.

2

What do HSV-1 and HSV-2 cause?

HSV- 1 'cold sores' and 2 'genital herpes'.
via direct skin, genital or eye contact tw/ vesicle fluid from HSV lesions can cause..
1. ulcers (both)
2. encephalitis (HSV-1)
3. Meningitis (HSV-2)
4. Neonatal herpes - vertical transmission via mother's genital tract

3

What does herpes virus - Varicella Zoster Virus cause?

Primary infection - chicken pox, reactivation = herpes zoster/shingles

4

How does varicella virus spread?

Respiratory droplets of vesicle fluid from infected person, after primary infection latency established in dorsal root ganglion.

5

What is chicken pox?

febrile illness with widespread vesicular rash. Usually uncomplicated but sometimes can cause pneumonitis (esp adults), encephalitis, acute cerebellar ataxia

6

What are shingles/herpes zoster?

reactivation causing unialteral vesicles in a dermatomal dsitribution.

7

What is Epstein Barr/Glandular Fever/ Infectious Mononucleosis?

Virus spread by saliva and genital secretions. Causes - sore throat, fever, lymphadenopathy, hepatosplenomegaly.
Atypical lymphocytes in blood film - look like monocytes therefore mononucleosis.

8

What is cytomegalovirus?

CMV spread via saliva/gential secretions or donated organs. Causes infective mononucleosis primarily.
- Congenital infection = in mothers with virus babies can have retinitis, deafness, microcephaly.
- In immunosuppressed transplant patients
- In patients with HIV/AIDS reactivation of latent CMV can cause retinitis or colitis.

9

What is rhinovirus?

'common cold' - aerosolised respiratory secretions.

10

What is influenza?

Resp virus - can spread b/w species. A, B and C.
- Influenza A mutates regularly.
- viral surface proteins H & N have multiple variants.

11

What S and S in primary influenza illness?

fever, myalgia, headache, cough, nasal discharge, sore throat.

12

What S & S in Post-influenza secondary bacterial lung infection?

with S. pneumonia, H. influenzae, S. aureus.

13

What respiratory syncytial virus?

RSV occurs in winter, aerolised transmission of rest secretions.
- commonest in young children.
- can cause BRONCHIOLITIS in children under 2yrs. -> Inflammation of bronchioles cause cough, wheeze, hypoxia, fever.

14

When does AIDS results from HIV?

When virus load increases and T lymphocyte (CD4) cells fall. AIDS defining illnesses = TB, pneumocystis, pneumonia

15

How are hepatitis A and E spread and what are symptoms?

faeco-orally & nausea, myalgia, arthralgia, fevers, juandice, URQ pain

16

How are hepatitis B and C spread?

blood-borne. (Hep D = defective virus & can only survive with B).

17

What is the epidemiology of hepatitis A?

developing world (Europe), mostly children, lower socioeconomic groups

18

What is epidemiology of Hepatitis E?

Asia, Africa- associated with contaminated water. In developed countries w/ pigs & undercooked meat. Fulminant hepatitis in pregnant women.

19

How is Hep B transmitted?

vertically, sexually, parenterally. Most asymoptomatic but can become chronic and develop -> cirrhosis -> hepatocellular carcinoma.

20

How is Hep C transmitted?

IVDU, transfusion (sexually less common). 85% chrohic and then -> c -> hc c

21

What is Norwalk/norovirus?

ssRNA virus - common w/ short-lived immunity, esp. in point-source outbreaks e.g. hospitals.
- caused by ingestion/inhalation of vomit particles.
- vomiting dominant feature

22

What is Rotavirus?

dsRNA virus esp in childhood. Seasonal (winter).
- faced-orally spread, via contaminated food, aerosolised faeces.
- Symptoms = fever, vomiting and watery diarrhoea.

23

What are enteroviruses?

Polio, Coxsackie A and B, enterovirus and echovirus.
Epi = mostly in summer, most under 15Y
Spread & Path- faec-orally, don't cause GI symptoms -> LN -> viraemia
Syndromes to all = fever-rash in children, meningitis, encephalitis, severe disseminated diseases in neonate
Specific syndromes = Herpangina (mouth blisters) => Coxsackie A. Pericarditis => Coxsackie B.

24

What is parvovirus?

'slapped cheek syndrome'
- respiratory droplet transmission
- infects erythrocyte progenitor cells causing transient anaemia
Clinical Syndromes Associated:
1. Erythema Infectious = fever, fiery rash on cheeks.
2. Transient aplastic crisis = (affects those w/ high RBC turnover) e.g. sickle cell causes dyspnoea, confusion, cardiac failure,
3. Infection in pregnancy - fetal loss can occur, can develop hydrous fetalis - severe foetal anaemia, oedema, ascites, heart failure.

25

What is a prion?

small infectious pathogen containing protein but no nucleic acid.
- resistant to protease if gene mutation leads to misfolding
- accumulate in cell and can cause spongiform change
-inherited or consumed
e.g. Sporadic Creutzfeld-Jackob disease = rare, gene mutation, progressive ataxia & depression then death
e.g. nvCJD linked to BSE (bovine, spongiform encephalopathy) same structure as prion.