Microbiology 13 - Opportunistic viral infection

Question 1

What system is used to classify viruses?

Answer 1

Baltimore classification system

Question 2

What class of viruses form latent infections?

Answer 2

DNA viruses

Question 3

How is most viral serology performed?

Answer 3

Indirectc ELISA

Question 4

Recall 3 reasons for immunosuppression

Answer 4

1. Solid organ transplant
2. Human stem cell transplant (short term, or long term if they have significant GVHD)
3. HIV/AIDS

Question 5

Recall 4 types of immunosuppressing drugs

Answer 5

1. Steroids
2. Calcineurin inhibitors
3. Anti-proliferative agent (eg. Azothioprine/ mycophenolate)
4. Antibodies

Question 6

What is the most important opportunistic virus in transplant patients?

Answer 6

CMV

Question 7

What virus causes multifocal leukoencephalopathy?

Answer 7

JC virus

Question 8

What is a common re-activator of latent HSV?

Answer 8

Stressful situations

Question 9

What is HHV4?

Answer 9

EBV

Question 10

What is HHV8?

Answer 10

Kaposi’s sarcoma associated herpesvirus

Question 11

What drug would you give to someone who has CMV AND is immunosuppressed?

Answer 11

Valganciclovir

Question 12

For which hepatitis viruses are there vaccines?

Answer 12

Hep A and B

Question 13

Why is adenovirus particularly problematic in post-bone marrow transplant children?

Answer 13

You get disseminated disease

Question 14

What is the treatment for disseminated adenovirus?

Answer 14

Cidofavir

Question 15

In which patients does JC virus cause PML?

Answer 15

AIDS patients

Question 16

What two conditions can BK virus cause in the immunosuppressed?

Answer 16

• *Stem cell transplant:** Haemorrhagic cystitis
• *Renal transplant:** Nephropathy

If have a patient with haematuria and lots of clots, think about this

Question 17

What disease does parvovirus cause in a chronically immunosuppressed patient?

Answer 17

Anaemia

Question 18

In renal transplants, is risk of CMV transmission when the donor or recipient is positive?

Answer 18

Donor is pos as recipient has never seen CMV before

Question 19

In Human Stem Cell Transplants, is risk of CMV transmission when the donor or recipient is positive?

Answer 19

Donor is neg (recipient is pos) as patient with CMV has immune system replaced with one that is CMV-naive

Question 20

Describe the pattern of symptoms caused by varicella infection in the immunocompromised

Answer 20

Pneumonitis, encephalitis and hepatitis
In neonate: purpura fulminans

Question 21

What is the most common malignancy caused by EBV?

Answer 21

Post-transplant lymphoproliferative disorder

Question 22

What is the most common clinical syndrome caused by CMV infection in immunocompromised? HOw is this idff to immunocomptenet?

Answer 22

immunosuppressed: Retinitis
immjnocompetent: tends to be asymptomatic or can cause infectious mononucleosis

Question 23

What CMV prophylaxis is offered, and to whom?

Answer 23

Ganciclovir
Given to all transplant patients

Question 25

Recall which infections affect HIV patients?

Answer 25

Question 26

What is HHV3?

Answer 26

VZV

Question 27

Solid organ transplant vs stem cell transplant: viral infections

Answer 27

**Solid organ transplant:** - viral reactivation occurs \>1month after **Stem cell transplant:** - viral reactivation occurs within 1 month as there's extensive immunosuppression

Question 28

What are the 3 sources of infection following transplant?

Answer 28

Question 29

Are herpes viruses DNA or RNA viruses?

Answer 29

DNA viruses

Question 30

What is a defining feature of herpes viruses?

Answer 30

they have a tendency to reactivate in immunocompromised patients and persists for life in the host

Question 31

Where do VZV, EBV and CMV cause latent infection?

Answer 31

VZV: dorsal root ganglion EBV: B cells CMV: dendirtic cells and monocytes

Question 32

Which HHV's tend to reactivate in BM transplant patients?

Answer 32

HSV, HHV6 and HHV7

Question 34

HSV1 vs HSV 2

Answer 34

HSV1- oral/ mucocutaneous HSV2- genital

Question 35

Indications for HSV prophylaxis

Answer 35

* CD4 \<200 in HIV/AIDS * Bone marrow: * 1 month (until engraftment) * Solid organ: * 3-6 months prior to transplant * And if treated for rejection

Question 36

When does VZV present?

Answer 36

* Usually a late complication in post-transplant * Can be an early manifestation in HIV: * → indication for HIV testing particularly in young person

Question 37

How does VZV present in immunocmpmroised?

Answer 37

Really severe Multi-dermatomal Can disseminate → associated with high mortality

Question 38

What is PTLD?

Answer 38

post-transplant lympho-proliferative disorder ## Footnote Immunosuppression used in organ transplants → breakdown of immunosurveillance keeping B cells and EBV in check → polyclonal expansion of B cells → predisposes to lymphoma

Question 40

What is the pathological hallmark of CMV?:

Answer 40

Owl’s eye appearance on lung pneumocytes due to inclusion bodies

Question 41

How much immunosuppression is needed post-transplant in SOT vs HSCT?

Answer 41

* Solid Organ Transplant * requires lifelong immunosuppression * Haematological Transplant * intense immunosuppression * for a relatively short period of time

Question 42

Kaposi sarcoma histology

Answer 42

spindle cell proliferation neo-angiogenesis inflammation and oedema