HIV Flashcards
if a someone with HIV bites someone else, what management is needed?
REASSURANCE + WOUND CARE
the risk of HIV transmission through a human bite is negligible, especially when the bite results in minimal bleeding. Saliva contains enzymes that inhibit HIV replication, and transmission through saliva alone is exceptionally rare. PEP is not indicated.
How is HIV transmitted?
HIV is transmitted through blood, semen, vaginal fluids, rectal fluids, and breast milk.
what GI symptom is common in HIV pts?
Diarrhoea is common in patients with HIV. This may be due to the effects of the virus itself (HIV enteritis) or opportunistic infections
possible causes of diarrhoea in HIV?
Cryptosporidium + other protozoa (most common)
Cytomegalovirus
Mycobacterium avium intracellulare
Giardia
what is the most common cause of diarrhoea in HIV?
Cryptosporidium is the most common infective cause of diarrhoea in HIV patients. It is an intracellular protozoa and has an incubation period of 7 days.
how do you identify cyrptosporidium in HIV?
Presentation is very variable, ranging from mild to severe diarrhoea. A modified Ziehl-Neelsen stain (acid-fast stain) of the stool may reveal the characteristic red cysts of Cryptosporidium.
mx of cryptosporidium in HIV?
supportive therapy
*nitazoxanide is licensed in the US for immunocompetent patients
what is mycobacterium avium?
atypical mycobacteria seen with the CD4 count is below 50
typical features of mycobacterium avium in HIV?
Typical features include fever, sweats, abdominal pain and diarrhoea. There may be hepatomegaly and deranged LFTs. Diagnosis is made by blood cultures and bone marrow examination.
how do you mx mycobacterium avium in HIV?
rifabutin, ethambutol and clarithromycin
what is kaposis sarcoma?
how do you manage HIV?
Antiretroviral therapy (ART) involves a combination of at least three drugs, typically two nucleoside reverse transcriptase inhibitors (NRTI) and either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI).
when do you start ART in HIV?
as soon as they have been diagnosed with HIV
examples of entry inhibitors for HIV?
action?
maraviroc (binds to CCR5, preventing an interaction with gp41), enfuvirtide (binds to gp41, also known as a ‘fusion inhibitor’)
prevent HIV-1 from entering and infecting immune cells
examples of NRTI for HIV?
S/E?
examples: zidovudine (AZT), abacavir, emtricitabine, didanosine, lamivudine, stavudine, zalcitabine, tenofovir
general NRTI side-effects: peripheral neuropathy
tenofovir: used in BHIVAs two recommended regime NRTI. Adverse effects include renal impairment and ostesoporosis
zidovudine: anaemia, myopathy, black nails
didanosine: pancreatitis
examples of NNRTI in HIV?
s/e?
examples: nevirapine, efavirenz
side-effects: P450 enzyme interaction (nevirapine induces), rashes
examples of protease inhibitors for HIV?
s/e?
examples: indinavir, nelfinavir, ritonavir, saquinavir
side-effects: diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme inhibition
indinavir: renal stones, asymptomatic hyperbilirubinaemia
ritonavir: a potent inhibitor of the P450 system
examples of integrate inhibitors in HIV?
action?
block the action of integrase, a viral enzyme that inserts the viral genome into the DNA of the host cell
examples: raltegravir, elvitegravir, dolutegravir
focal neurological lesions in HIV?
Toxoplasmosis
Primary CNS lymphoma
TB
what is toxoplasmosis?
features, imaging, mx
what is primary CNS lymphoma>?
features, imaging, mx
what is this?
toxoplasmosis
what is this?
primary CNS lymphoma
how do you differentiate between tosxoplasmosis and CNS lymphoma?
how is TB seen in HIV?
much less common than toxoplasmosis or primary CNS lymphoma
CT: single enhancing lesion
general neurological disease in HIV?
encephalitis
cryptococcus
PML
AIDS dementia complex
what is encephalitis?
may be due to CMV or HIV itself
HSV encephalitis but is relatively rare in the context of HIV
CT: oedematous brain
what is cryptococccus?
features, ix, mx
what is PML?
features, ix, mx
what is AIDS dementia complex?
caused by HIV virus itself
symptoms: behavioural changes, motor impairment
CT: cortical and subcortical atrophy
what is oesophageal candidiasis in HIV?
Oesophageal candidiasis is the most common cause of oesophagitis in patients with HIV. It is generally seen in patients with a CD4 count of less than 100. Typical symptoms include dysphagia and odynophagia. Fluconazole and itraconazole are first-line treatments.
what opportunistic infections occur at CD4 count 200-500?
what opportunistic infections occur at CD4 count 100-200?
what opportunistic infections occur at CD4 count 50-100?
what opportunistic infections occur at CD4 count <50?
what are key features of HIV associated nephropathy?
massive proteinuria resulting in nephrotic syndrome
normal or large kidneys
focal segmental glomerulosclerosis with focal or global capillary collapse on renal biopsy
elevated urea and creatinine
normotension
what is HIV seroconversion?
HIV seroconversion is symptomatic in 60-80% of patients and typically presents as a glandular fever-type illness. Increased symptomatic severity is associated with poorer long-term prognosis. It typically occurs 3-12 weeks after infection
features of HIV seroconversion?
sore throat
lymphadenopathy
malaise, myalgia, arthralgia
diarrhoea
maculopapular rash
mouth ulcers
rarely meningoencephalitis
how do you diagnose HIV seroconversion?
HIV antibodies - usually consists of both a screening ELISA (Enzyme Linked Immuno-Sorbent Assay) test and a confirmatory Western Blot Assay. present at 3 months
p24 antigen - raised at 1 to 3/4 weeks after infection
testing for HIV in asymptomatic patients should be done at 4 weeks after possible exposure
after an initial negative result when testing for HIV in an asymptomatic patient, offer a repeat test at 12 weeks
what is used for HIV screening?
HIV antibody and HIV antigen
p24 antigen can be detected as early as 2-3 weeks after exposure
