infections in the immunocompromised

Question 1

What immunity is lacking in HSCT?

Answer 1

Initally both innate and adaptive
Innate recovers after 1 month
Adaptive is abnormal for years

Question 2

What immunity is lacking solid organ transplants?

Answer 2

Predominantly adaptive immunity
Dont have inital period of innate immune loss unlike HSCT
Adaptive immune defects persist as continue on long term immunosuppression

Question 3

Immune defect seen with chemo?

Answer 3

Innate immunity affected, neutrophils are commonly decreased

• infections with gram positives and gram negatives
• prolonged neutropenia can cause fungal infections

Question 4

Immune defect seen with TNF-alpha inhibitors?

Answer 4

TNF alpha is important for development of innate immune system - particulary involves organisms that are sequestered in granulomas (Tb, MAC, aspergillous)

Question 5

Immune defect in HIV?

Answer 5

Adaptive immunity

- loss of CD4 cells

Question 6

Features of norcardia infection?

Answer 6

Gram positive
High risk in those with impairment of adaptive immunity
Sites of infection: lung (multiple or single nodules), CNS (abscesses), cutaneous (mycetoma - painless nodule)
Treatment: Cotrimoxazole, carbapenums

Question 7

Features of disseminated of MAC?

Answer 7

Fever, night sweats, bone marrow suppression
organomegaly, diarrhoea, raised LFTs
Treat with macrolides + rifampicin

Question 8

What infections are seen in splenectomy patients and why?

Answer 8

Encapsulated organism
- strep pneumoniae
- haemophilis influenzae
- neisseria meningitidis
- klebsiella pneumonaie, salmonella
Absence of splenic macrophages which usually destroy opsonised bugs

Question 9

Features of CMV infection?

Answer 9

Highest risk period 1-4 months after transplant
Features:
- hepatitis
- GI ulceration
- meningoencephalitis/retinitis (only in HIV patients)
- pneumonitis (lower lobe infiltrates spreading upwards)
- prolonged fevers and flu like symptoms
- bone marrow suppression

Question 10

Treatment of CMV?

Answer 10

Gancylcovir (myelosuppression)
Foscarnet
Cidovofir

Question 11

How do you detect CMV in transplant patients?

Answer 11

Monitor CMV PCR weekly and treat when positive for 2 consecutive measurements

Question 12

What is EBV lymphoproliferative disease?

Answer 12

abnormal outgrowth of EBV infected cells
presents with fever and lymphadenopathy
pathology: B-cell hyperplasia
Treatment: Rituximab
Highest risk intestinal or multiorgan transplant

Question 13

What is oral hairy leukoplakia associated with?

Answer 13

Occurs in HIV patients with EBV

Treat with acyclovir

Question 14

What are the risks of VSV in immunocompromised?

Answer 14

VSV hepatitis - fatal
Shingles - lengthly risk, up to a year post transplant
- lesions last for longer and can get pneumonitis, meningioencephalitis from shingles

Question 15

Prophylaxis for vSV?

Answer 15

VSV if exposed

Aciclovir

Question 16

Complications of HSV in immunocompromised patients?

Answer 16

reactivate latent virus to cause encephalitis, heaptitis, pneumonitis, oesophagitis
Can prophylax with acyclovir

Question 17

Manifestations of HHV-6?

Answer 17

Limbic encehpalitis, pneumonitis and disseminated disease

Question 18

What are the manifestations of HHV-8 (KSHV)

Answer 18

Kaposis sarcoma
Primary effusion lymphoma
Multicentric castlemans disease

Question 19

Manifestations of candida?

Answer 19

Mucocutaneous candida - oral, vaginal, paronychia

Invasive disease with oesophageal infection, haematogenous seeding to brain, heart, kidneys, retina

Question 20

Clinical manifestations of aspergillous infection?

Answer 20

invasive pulmonary aspergillosis

disseminated aspergillous with haemorrhagic infarction, cerebral abscesses, cutaneous necrotic eschars and endocarditis

Question 21

Features of cryptococcal infection?

Answer 21

Subacute, headache, fever, lethargy
Focal neurology
Chronic meningitis with hydrocephalus
Diagnosed with crytpcoccal antigen test and indian ink stain

Question 22

Treatment of cryptococcus?

Answer 22

Amphotericin B + flucytosine, ongoing oral fluconazole after

Question 23

Features of PJP?

Answer 23

fever, non productive cough, SOB
HYPOXIA
Bilateral ground glass infiltrates more apparent on CT than CXR

Question 24

Treatment of PJP?

Answer 24

Cotrimoxazole

Question 25

What is strongyloides hyperinfection syndrome?

Answer 25

Helminth
Massive dissemination of larvae into lungs, heart, liver, CNS
Present with fever, haemoptysis, diarrhoea, vomitting
Treat with ivermectin

Question 26

Features of toxoplasmosis?

Answer 26

cerebral

• altered mental state
• fever
• headache
• focal neurology

Question 27

Findings on CT head?

Answer 27

Ring enhancing lesion/lesions

Question 28

Treatment of toxoplasmosis?

Answer 28

Treatment is sulphadiazine/pyrimethamine + folinic acid

Question 29

Features of cryptosporidium?

Answer 29

weight loss, diarrhoea, abdo pain

biliary involvement

Question 30

Treatment of cryptosporium?

Answer 30

Usual treatment for cryptosporidum - nitazoxamide - not effective in HIV patients
Need to treat with ART