Virology in Primary Care

Question 1

• How often do viral infections not need any intervention?

Answer 1

90% of the time, because most are self-limiting and resolve within a week

Question 2

• What sorts of things are you looking for in the lab at the different stages (acute or chronic) of a viral infection?

Answer 2

o Acute presentation you want to look for:
- IgM (as this is the first immunoglobulin you make against a pathogen in an infection)

o Chronic presentation
- IgG (as this is the more specific immunoglobulin you make and keep forever after acute infection

Question 3

• What are the common viral ‘exotic emergencies’ and where do they come from:

• Ebola haemorrhagic fever
• Rabies
• Middle eastern respiratory syndrome coronavirus MERS CoV
• Avian influenza A

Answer 3

1) africa = bats
2) developing countries = animal bites
3) middle east = camels
4) asia = birds

Question 4

• How do the following conditions present (they all get rashes)?

Measles
- face features?

Rubella

• painful what?
• swollen glands?

Parvovirus B19

• when does it get worse?
• nickname?

Varicella zoster

which one is treated with acyclovir?

Answer 4

MEASLES

• conjunctivitis
• koplik’s spots (white lesions in mouth)
• florid maculopapular rash

RUBELLA

• LESS florid rash
• swollen glands behind ears
• aching and painful joints

PARVOVIRUS B19

• slapped cheek syndrome
• maculopapular rash more on face
• gets worse/reappears in heat

VARICELLA ZOSTER (shingles)

• itchy rash all over body
• fever, tiredness, headaches last up to a weekVaricella zoster (used in shingles)

Question 5

• What is acyclovir usually used to treat?

Answer 5

o Herpes simplex virus (used for genital herpes but not for cold sores)
o

Question 6

• What is the main limitation with acyclovir?

* Which drugs are similar but have better bioavailability?

Answer 6

There is a low bioavailability so you need to take it 5 times a day so patient’s rarely take them as they should.

Valacyclovir and famciclovir.

Question 7

• What is the structure of the influenza virus?

Answer 7

Single stranded RNA virus with 8 bots of RNA inside.

Question 8

• What is the main reservoir for the flu virus?

Answer 8

Water birds

Question 9

• What antivirals do we have against the influenza virus?

* When are these antivirals effective?

Answer 9

1. Neuraminidase inhibitors – neuraminidase is an enzyme that helps the virus slip out of one cell and infect another cell in the respiratory tract
2. Oseltamavir (Tamiflu) and Zanamivir (Relenza) – prevents enzyme function in the virus

Only within the first 48 hours of symptoms