HIV Flashcards
Discuss risk for transmission of HIV
The highest risk exposure is transfusion with HIV positive blood.
Other risk factors include
- exposure to serum with high viral load
- lack of male circumcision
- presence of ulvertive sexually transmitted infection.
Type of sex
1-30% transmission for receptive anal
0.1-10% for receptive vaginal and insertive anal intercourse
0.1-1% for insertive vaginal intercourse.
Discuss primary HIV infection
Primary infection with HIV often causes an acute self limited viral infection. The most common finding are mononucleosis like symptoms that consist of fever, pharyngeitis and lymphadenopathy.
This usualy occurs at the 2- 6 week period after transmission; During this time the virus is actively replicating and ABs to HIV have not been made
Large public health benifits to diagnosis at this stage. Patients with acute HIV infection transmit the infection disproporitionately - these patient often do no know that they are infected and thier viral load may be in the range of milions.
Illness usually last 2 wweek,s
Among other PCP, toxoplasmosis CMV and thrush may occur at this stage.
Diagnosis depends on having HIV as a differential for the non specific constelattion of syndrome. ABs are likley to be -ve and diagnosis is made on viral load titres
Describe Chronic HIV infection
After the primary infection there is generally a prolonged clinical latent period. In this stage aside form frequent generalised lymphadenotpathy many patient ahve little or no clinical manifestations of HIV infection.
The general onset of AIDS from seroconversion is 8-10 years. Certain patients are long term non -progresses and have remained free of symptoms without ART for more than 25 years.
Define AIDS
CD4 count below 200cell/ul or the presence of AIDS defining conditions. At this level immune dysfunction is severe and without ART survival is short.
Some conditions are so common in patients with ADIS that primary prophylaxis is indicated and is cost effective.
- PCP prophylaxis starts when CD4n counts are less than 200 - BACTRIM
- toxoplasmosis when CD4 counts less than 100 - BACTRIM
- mycobacterium avium if CD4 <50 - AZITHRO
List AIDS defining illness
- Candidiasis of bronchi, trachea or lungs or oesophagus
- Cryptococcus -extrapulmonary
- CMV disease (other than liver, spleen or nodes)
- CMV retinitis (with loss of vision)
- HSV bronchitis or oeophagitsi
- Burkitts lymphoma
- Kaposi sarcoma
- Mycobacterium avium
- TB
- PCP
- salmonella septicaemia
Discuss pulmonary manifestation of HIV/AIDS
Increase risk of PCP as CD4 count drops below 200
-increased risk of lung CA, emphysema, cryptogenic organizing penumonia, sarcoidosis, drug hypersensitivty, pirmary effusion lymphoma
Risk of TB increases with declining immune function - treatment of TB in patients with HIV is very complicated due to interaction between ART and TB drugs
DIscuss clinical features of PCP and treatment regime
Characterised by gradual onset of fever cough and progressive dyspnoea. The cough is generally non producitve although sputum load does not exclude as coinfection with bacterial pneumonia is common.
Some patietns especially those taking nonsystemic prophylaxis (areosolized pentamidine) may ahve extrapulmonary signs including hepatosplenomegaly, skin lesions and occular liesions.
Bloods - CD4 count under 200 and raised LDH
CXR - bilateral patchy alveolar or interstitial infiltrates.
CT: ground glass or cystic lesions.
DOuble strength bactrim is the preferred PCP prophylaxis
Discuss GIT manifestations of HIV
THose receiving ART may suffer treatment related adverse GIT events including pancreatitis, hepatic steatosis lactic acidosis and drug induce hepatotoxicity.
Oropharyngeal thrush is an extremely common opptunisitc organism seen in HIV
Oral hairy leukoplakia caused by EBV is also common manigested as raised white lesions on the side of the toungue.
Oeosphagitis particularly inthose with CD4 countsunder 100 caused by candida HSV and CMV and deep apthous ulcers.
Discuss CNS manifestations of HIV
Common problems include cryptococcal meningitis, toxoplasmosis primary central nervous system lymphoma and progressive multifocal leukencephaloapthy.
HIV itself is a neurotropic virus and patients with acute infection can present with aseptic meningitis with complaints of heaache and meningisms.
Cryptococcus neoformans is the most common cause of menigitis in patients with AIDS. Usually seen with profound immunosupression with CD4 counts under 100. LP shows high opening pressure realitvely normal WBC and CRAG (cryptococal antigen) - treated with amphortercin B then fluconazole
FOcal CNS lesions including toxoplasma and EBV related primary CNS lymphoma + burkitts
Discuss cutaneous manifestation of HIV
Any WHO criteria for stage 4 HIV disease
- Chronic herpes simplex virus ulcers
- extrapulmonary TB
- Kaposi’s sarcoma
- extrapulmonary cryptococcosis
- Disseminated mycosis
- Atypical disseminated leishmaniasis
- disseminated non TB mycobacterial infection
- extrapulmoanry cryptococcosis including menigitis
Facial mulluscum in an adult proximal subungal onchomycosis herpes zoster scarring oral hairy leukoplakia bacillary angiomatosis widespread dermatophytosis severe seborrheic dermatitis
Discuss management of HIV
ART has led to a dramatic reduction in morbidity and mortality from opportunisitic disease and non-AIDS conditions.
The goal of therapy is to suppress viral replication and reconstitute the immune system.
Antiretroviral target the major viral enzymes - reverse transcriptase, protease and integrase. ART involves the use fo three active drugs usually two NRTIs and another agent.
Unfortunatley side effects from ART are extremely common
-protease inhibitos - GIT side effect such as nausea and vomiting
- NRTI- are mitochondrial toxic and can cause pancreatitis and hepatitis
Other - hepatic necrosis, gilbert like syndrome and neurospychiatric problems
Discuss postexposure prophylaxis
Prior to PEP using ART rate of transmission via needle stick was approxiamatley 0.3% - much lower if PEP is used.
Initial response to an exposure is immediate cleansing of the exposed or injured site; soap and water can be used for intact skin and virucidal antispetic agents such as alchol based hand hegiene agents can be used for small punctures.
Preferred regimens for PEP mirror the treatment of HIV with a three drug combination therapy with a dual NRTI backpone plus an integrase strand transfer inhibotr
A commonly recommended regimen with a low toxicity provile and minimal drug interaction is tenofovir-emtricitabine (Truvada) along with the INSTI raltegravir
If the exposed person is to recieve PEP the goal is to initiate therapy within 1-2 hours after exposure - the efficacy of PEP greatly decreases after 24-36 hours. Follow-up HIV testing should occur at 6 weeks
3months and 6 months
PEP should still be given if patient presenting within 72 hours with potentional exposure to the virus
