Viruses

Question 1

Epstein-Barr Virus (EBV)

1/2

Answer 1

Ds-DNA, enveloped virus
Infects B-cells —> T-cell proliferation
Splenomegaly (destruction of B cells)
Sore throat, headache

Treatment: Acyclovir. Supportive treatment.

Question 2

Epstein-Barr Virus (EBV)

2/2

Answer 2

Complications: 
Hodgkin’s lymphoma- Reed-Sternberg cells (owl like) 
Gastric lymphoma
Burkitts lymphoma 
Nasopharyngeal carcinoma

Question 3

Varicella zoster virus (VZV)

Answer 3

Enveloped DNA virus
First presentation as chickenpox- young
Causes vesicular rash
Latent infection in dorsal root ganglion
Reappears as Shingles in single dermatome (older and immunocompromised)- more severe infection

Treatment: Acyclovir- viral replication inhibitor

Question 4

Hepatitis B

1/2

Answer 4

DsDNA, enveloped 
Fatigue, loss of appetite, abdominal pain, nausea.
CIRRHOSIS and JAUNDICE. 
Blood borne virus. 
Incubation= 6 weeks- 6 months. 

If HbsAg still present after 6 months- indicates chronic infection.

Question 5

Hepatitis B

2/2

Answer 5

Investigations:
Raised: ALP, ALT, bilirubin
HepB serology (HbsAg / HbcAg)
PCR- HBV DNA present

Treatment: 
Vaccine prophylaxis: HbsAb 
Supportive treatment 
Disease is self-limiting
Chronic infections= no cure - would require lifelong antiviral to suppress HBV replication.

Question 6

Hepatitis C

1/2

Answer 6

Blood borne virus
Association with IV drug users
80% chronically infected- leads to end stage liver disease = hospitalisation// transplant.
Mostly asymptomatic BUT can get fatigue, anorexia, nausea, abdominal pain.
JAUNDICE and CIRRHOSIS.
Associated with hepatocellular carcinoma.

Question 7

Hepatitis C

2/2

Answer 7

Investigations:
Serology- Anti HepC ab
PCR- HCV present

Treatment-
Ribovarin and interferon (8-12 weeks)
Can get reinfected
NO VACCINE

Question 8

Human immunodeficiency virus (HIV)

1/2

Answer 8

SsRNA enveloped retrovirus (contains reverse transcriptase)
Presents with opportunistic illnesses:
A. Oral candidiasis- Candida albicans
B. Kaposi’s sarcoma- HHV8
C. Pneumocystitis pneumonia - Pneumocystitis jirovecii

Also reactivation of latent infections- shingles, EBV, CMV (cytomegalovirus)

Question 9

Human immunodeficiency virus (HIV)

2/2

Answer 9

Infects CD4+ T cells
Viral load is inversely proportional to CD4+ cell count.
If T cell <200 then progression to AIDs (<500, <350 = symptoms)

Treatment:
HAART (highly active antiretroviral therapy)
2 x nucleoside reverse transcriptase inhibitors PLUS
Any 1 of
A. Non-nucleoside reverse transcriptase inhibitor
B. Protease inhibitor
C. Integrate inhibitor

Question 10

Adenovirus

Answer 10

DsDNA, non-enveloped
Replicates within endothelial cells

Symptoms: conjunctivitis, sore throat, fever, cough

Treatment: supportive treatment.