infections in the immunocompromised Flashcards
What immunity is lacking in HSCT?
Initally both innate and adaptive
Innate recovers after 1 month
Adaptive is abnormal for years
What immunity is lacking solid organ transplants?
Predominantly adaptive immunity
Dont have inital period of innate immune loss unlike HSCT
Adaptive immune defects persist as continue on long term immunosuppression
Immune defect seen with chemo?
Innate immunity affected, neutrophils are commonly decreased
- infections with gram positives and gram negatives
- prolonged neutropenia can cause fungal infections
Immune defect seen with TNF-alpha inhibitors?
TNF alpha is important for development of innate immune system - particulary involves organisms that are sequestered in granulomas (Tb, MAC, aspergillous)
Immune defect in HIV?
Adaptive immunity
- loss of CD4 cells
Features of norcardia infection?
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
Features of disseminated of MAC?
Fever, night sweats, bone marrow suppression
organomegaly, diarrhoea, raised LFTs
Treat with macrolides + rifampicin
What infections are seen in splenectomy patients and why?
Encapsulated organism - strep pneumoniae - haemophilis influenzae - neisseria meningitidis - klebsiella pneumonaie, salmonella Absence of splenic macrophages which usually destroy opsonised bugs
Features of CMV infection?
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
Treatment of CMV?
Gancylcovir (myelosuppression)
Foscarnet
Cidovofir
How do you detect CMV in transplant patients?
Monitor CMV PCR weekly and treat when positive for 2 consecutive measurements
What is EBV lymphoproliferative disease?
abnormal outgrowth of EBV infected cells presents with fever and lymphadenopathy pathology: B-cell hyperplasia Treatment: Rituximab Highest risk intestinal or multiorgan transplant
What is oral hairy leukoplakia associated with?
Occurs in HIV patients with EBV
Treat with acyclovir
What are the risks of VSV in immunocompromised?
VSV hepatitis - fatal
Shingles - lengthly risk, up to a year post transplant
- lesions last for longer and can get pneumonitis, meningioencephalitis from shingles
Prophylaxis for vSV?
VSV if exposed
Aciclovir
Complications of HSV in immunocompromised patients?
reactivate latent virus to cause encephalitis, heaptitis, pneumonitis, oesophagitis
Can prophylax with acyclovir
Manifestations of HHV-6?
Limbic encehpalitis, pneumonitis and disseminated disease
What are the manifestations of HHV-8 (KSHV)
Kaposis sarcoma
Primary effusion lymphoma
Multicentric castlemans disease
Manifestations of candida?
Mucocutaneous candida - oral, vaginal, paronychia
Invasive disease with oesophageal infection, haematogenous seeding to brain, heart, kidneys, retina
Clinical manifestations of aspergillous infection?
invasive pulmonary aspergillosis
disseminated aspergillous with haemorrhagic infarction, cerebral abscesses, cutaneous necrotic eschars and endocarditis
Features of cryptococcal infection?
Subacute, headache, fever, lethargy
Focal neurology
Chronic meningitis with hydrocephalus
Diagnosed with crytpcoccal antigen test and indian ink stain
Treatment of cryptococcus?
Amphotericin B + flucytosine, ongoing oral fluconazole after
Features of PJP?
fever, non productive cough, SOB
HYPOXIA
Bilateral ground glass infiltrates more apparent on CT than CXR
Treatment of PJP?
Cotrimoxazole
