HIV Flashcards
Describe HIV (3)
Human immunodeficiency virus.
Describes an RNA retrovirus that enters and destroys CD4 T-Helper cells.
Can progress to AIDS (Acquired immunodeficiency syndrome) which can result in immunocompromise and opportunistic infections
What type of cells does HIV attack?
CD4 T-helper cells
What is HIV seroconversion? (2)
Describes the time between exposure to a virus and when HIV antibodies become detectable in the blood.
Patients tend to develop flu-like symptoms in the first few weeks of infection (3-12 weeks).
Give 5 features of HIV seroconversion
Sore throat
Lymphadenopathy
Malaise, myalgia, arthralgia
Diarrhoea
Mouth ulcers
How is HIV transmitted? (3)
Unprotected anal, vaginal or oral sex
Mother to child during pregnancy, birth or breast feeding (vertical transmission)
Mucous membrane, blood or open wound exposure (i.e sharing needles, needle stick or blood splashed in eye)
Name 4 AIDS defining illnesses (opportunistic infections/illnesses associated with a low CD4 count)
Oral Thrush - Candida albicans
Shingles - Herpes zoster
Pneumonia - Pneumocystis jirovecii
Kaposi’s sarcoma - HHV-8
What test is used for HIV screening?
Fourth-Generation tests - HIV antibody and p24 antigen test
Can be detected as early as 2-3 weeks after exposure but results are more reliable after 45 days.
When should HIV testing be performed in asymptomatic patients? What is done if this test is negative? What is done if the test is positive?
4 weeks after possible exposure.
If negative, repeat test at 12 weeks.
If positive, repeat to confirm diagnosis
How does CD4 count relate to infection risk?
The lower the CD4 count, the higher the risk of opportunistic infections.
What is the normal CD4 range? What CD4 range puts patients at high risk of opportunistic infections?
Normal = 500-1200 cells/mm3
High risk of infections = <200 cells/mm3
What can be tested for to give an indication of viral load?
HIV RNA
Give 3 focal neurological lesions that HIV increases the risk of developing
Toxoplasmosis (most common)
Primary CNS Lymphoma - Epstein Barr virus
Tuberculosis
How would toxoplasmosis appear on a CT? What other test can be performed to distinguish from lymphoma?
Single or multiple ring enhancing lesion
Thallium SPECT negative
What is the treatment for a focal toxoplasmosis lesion in a patient with hiv?
Sulfadiazine and pyrimethamine
How may a toxoplasmosis lesion present? (3)
Headache, Confusion, Drowsiness
How may lymphoma present on CT? What other test can be used to distinguish from toxoplasmosis?
Single lesion with solid enhancement.
Thallium SPECT positive
How is CNS lymphoma associated with HIV managed?
Steroids + Methotrexate +/- radiotherapy
Give 2 generalised neurological conditions associated with HIV
Encephalitis (due to CMV or HIV)
Cryptococcus (most common fungal infection of CNS)
What treatment is offered to HIV patients?
Antiretroviral therapy (ART)
What type of test can establish the resistance of each HIV strain to different medications, to help guide treatment?
Genotypic resistance testing
When should ART be initiated in a patient with confirmed HIV?
As soon as they are diagnosed
What 5 classes of antiretroviral therapy are available?
Protease inhibitors (PI)
Integrase inhibitors (II)
Nucleoside reverse transcriptase inhibitors (NRTI)
Non-nucleoside reverse transcriptase inhibitors (NNRTI)
Entry inhibitors (EI)
What is the usual starting antiretroviral therapy regime?
Two NRTIs + either a PI or NNRTI
Name 2 Nucleoside reverse transcriptase inhibitors (NRTIs)
Tenofovir
Emtricitabine
Name 2 NNRTIs (non-nucleoside reverse transcriptase inhibitors)
Nevirapine
Efavirenz
Name 2 Protease inhibitors (PIs)
Indinavir
Nelfinavir
Name 3 side effects of protease inhibitors (indinavir/nelfinavir)
Diabetes
Hyperlipidaemia
Buffalo hump/central obesity
What prophylaxis is given to HIV patients? When is it given?
Prophylactic co-trimoxazole
To protect against pneymocystis jirovecii pneumonia
Given if CD4 count is <200
Give 3 additional management plans for HIV
Monitor lipids/give statin (HIV can increase risk CVD)
Annual cervical smears (HIV increases risk of HPV infection)
Vaccinations - Annual influenza, pneumococcal, HPV, Hep A/B
Name 2 vaccines that should be avoided in HIV patients, and why
BCG and Typhoid
As are live vaccines
How is HIV transmission prevented during pregnancy? (Use viral load load)
Under 50 - Normal vaginal delivery
Over 50 - Consider C-section
Over 400 - C-section
What is given as infusion during labour and delivery in a pregnant mother positive for HIV?
IV Zidovudine
What prophylaxis is given to babies born from HIV positive mothers? (2)
Low risk (mothers viral load <50) - Zidovudine for 2-4 weeks
High risk - Zidovudine, lamivudine and nevirapine for 4 weeks
Is it safe to breastfeed when HIV positive?
No. Breastfeeding should be avoided.
Breastfeeding can sometimes be attempted if viral load is undetectable but this needs to be closely monitored
What treatment can be offered after exposure, to reduce risk of transmission? When should it be offered?
Post-Exposure Prophylaxis (Emtricitabine/tenofovir + Raltegravir for 28 days)
Offered within 72 hours.
What renal condition can occur in HIV? What are 5 key features?
HIV associated nephropathy (HIVAN)
Features;
Massive proteinuria (nephrotic syndrome)
Normal/large kidneys
Focal segmental glomerulosclerosis
Elevated urea/creatinine
Normotension
