HIV Opportunistic Infections Flashcards
What causes PCP?
Pneumocystis jiroveci fungus
What are the features of a PCP infection?
Reduced sats on exertion History longer than three days High RR Dry cough, fever, chest pain Scanty sputum
How do you diagnose PCP?
CXR: diffuse B/L interstitial infiltrates. NAD in 10%
HRCT: groundglass
PCR or immunofluorescence on deep lung sample (induced with hypertonic saline)
Unlikely if on prophylaxis or CD4>200
How do you treat PCP?
21 days cotrimoxazole Then secondary prophylaxis
IV then PO when improving
Steroids if needing O2 on RA or high RR
Takes a while to improve
What are the guidelines for PCP prophylaxis?
Primary: if CD4<200 cotrim daily
Secondary: daily cotrim until CD4>200 for at least 3 months
What are the differential diagnoses for contrast enhancing CNS lesions in PLHIV?
Toxoplasmosis TB Lymphoma Fungal Abscess Mets/tumour
What are the differential diagnosis for diffuse/non focal MRI changes in PLHIV?
PML CMV encephalopathy HIV encephalopathy TB Cryptococcal meningitis Listeria meningitis
What is toxoplasmosis and how do you get infected with it?
A cat parasite, spread by the ingestion of cysts in raw meat or cat faeces
In HIV, infection is usually due to reactivation
How do you diagnose toxoplasmosis?
Focal CNS lesion ?multiple
CSF: high protein and lymphocytes, toxoplasmosis PCR (negative cannot be used to r/o Dx)
Toxo IgG- can rule out
Brain biopsy demonstrating parasites is the definite Dx
How do you treat toxoplasmosis?
Consider empirical Tx if >1 suggestive lesion, serology +ve and CD4<200
At least 6wks Tx
Sulfadiazine (or clindamycin), pyrimethamine and folate
Steroids if oedema or initial deterioration
What is the prophylaxis for toxo?
Secondary prophylaxis of cotrim daily until CD4>200
What are the features of primary CNS lymphoma?
EBV associated
More likely than toxo if solitary lesion, toxo -ve, lesion >4cm or no response to toxo Tx
How do you diagnose primary CNS lymphoma?
Biopsy
CSF cytology
+ve CSF EBV is supportive
How do you treat primary CNS lymphoma?
Median survival 4 months!
Palliative DXT and chemo
What are the pathogenic sub species of cryptococcus?
Cryptococcus neoformans var grubii
Cryptococcus neoformans var neoformans
What are the manifestations of cryptococcal disease?
Meningitis
Pulmonary disease- may have negative CrAg
Cutaneous
Bone and prostate
How would you diagnose cryptococcal meningitis?
CD4 <50
Severe HA, fever, confusion, focal neuro
CSF: high OP, high WCC and protein, low glucose, India ink +ve, CRAG +ve
BCs
High mortality due to RICP
What is the treatment for cryptococcal meningitis?
2wks liposomal amphotericin and flucytosine
8wks fluconazole
Monitor RICP: if OP>25 then daily LP to reduce and consider VP shunt
Secondary prophylaxis with fluconazole until CD4>100 for at least 3/12
What causes progressive multifocal leukoencephalopathy?
JC virus (Human polyomavirus 2) 70% adults are seropositive
What are the features of PML?
Progressive cognitive and neurological deficit
CSF: high protein and cells, PCR JV virus +ve
How do you treat PML?
Only Tx is ART
Median survival is 6 months
What is Mycobacterium Avium Complex?
Species of nonTB Mycobacterium
M avium is the most common cause of disseminated MAC disease in AIDS pts
What are the clinical manifestations of MAC?
CD4<50
Fever, weight loss, sweats, diarrhoea, lymphadenopathy, hepatosplenomegaly
Anaemia, hypoproteinaemia and deranged LFTs
How do you diagnose MAC?
Clinical history
Isolation of M.Avium from BCs, BM, LN, sputum
