HIV and AIDS Flashcards
How is HIV spread?
Sexual transmission
Injection drug misuse
Blood products
Vertical transmission
Organ transplant
How is HIV tested?
Point of Care Testing (POC)
Blood sample from individuals finger
Takes 60 seconds
Standard test will confirm result
Describe the immunology of HIV
Infects and destroys cells of the immune system especially the T-Helper cells that are CD4+
CD4 receptors are non-exclusive to lymphocytes - present on surface of monocytes and macrophages, cells in brain and skin, and other sites
Describe the natural history of HIV
CD4 count declines and HIV viral load increases
Increasing risk of developing infections and tumours
Severity of illness is greater if CD4 count is lower
Most AIDS diagnosis occurs when CD4 <200
What are some symptoms of clinical stage 1 HIV?
Asymptomatic
Persistent generalised lymphadenopathy
What are some symptoms of clinical stage 2 HIV?
Weight loss
Minor mucocutaneous manifestations
Herpes zoster
Recurrent upper resp tract infections
What are some symptoms of clinical stage 3 HIV?
Weight loss
Unexplained chronic diarrhoea
Unexplained prolonged fever
Oral candidiasis
Oral hairy leucoplakia
Pulmonary tuberculosis
Severe bacterial infections
What are some symptoms of clinical stage 4 HIV?
HIV wasting syndrome
Pneumocystis pneumonia
Toxoplasmosis
Cryptococcosis
HSV
Progressive multifocal leukoencephalopathy
What is the difference between AIDS and HIV?
HIV - no symptoms
AIDS - certain infections and tumours which develop to a weakness in immune system
If AIDS then put on antivirals
What are some AIDS defining conditions?
Tuberculosis
Pneumocystis
Toxoplasmosis
Kaposi’s sarcoma
Cervical cancer
Persistent cryptosporidiosis
What is the progression of HIV?
Acute infection - seroconversion
Asymptomatic
HIV related illnesses
AIDS defining illness
Death
Describe primary HIV/ seroconversion
Approx. 30-60% of patients have seroconversion illness when HIV antibodies first develop
Abrupt onset after 2-4 weeks after exposure
Self limiting 1-2 weeks
Symptoms non-specific
What are the symptoms of primary HIV?
Flu-like illness, fever, malaise, lethargy, pharyngitis, lymphadenopathy and toxic exanthema
Looks like glandular fever but no EBV serology
Describe pneumocystis jiroveci pneumonia
Commonest late stage AIDS infection
Opportunistic infection
CD4 cell count usually less than 200
Classification is dry cough and increasing breathlessness over several weeks
What investigations are used for pneumocystis jiroveci pneumonia?
Chest X-ray
Induced sputum or bronchoscopy for PCR
What is the treatment for pneumocystis jiroveci pneumonia?
Cotrimoxazole
Pentamidine
Prophylaxis until CD4 is under 200
Describe antiviral therapy for HIV
Different classes of drugs acting on different stages of HIV lifecycles
Combination antiviral therapy means 3 drugs of at least 2 groups
Adherence need to be over 90%
Where does the antiviral treatment act?
Reverse transcription inhibitors
Integrase inhibitor
Protease inhibitors
When should antiviral therapy start?
All patients at diagnosis regardless of CD4 count and viral load
If CD4 less than 350 then risk of symptoms without treatment
If CD4 under 200 then need to start as soon as possible
Any pregnant women before 3rd trimester
When is combination therapy adjusted?
If viral load is not adequately suppressed after 4-6 weeks
What is the current life expectancy for HIV and AIDS?
If CD4 under 100 - 52%
If 100-200 - 62%
If over 200 - 70% +
How long does treatment last?
Life long
May need to changed but always need to on some form of antiviral medication
Why do treatments fail?
Poor adherence levels to viral mutation and resistance
Incomplete suppression - inadequate potency, drug levels, adherence and pre-existing resistance
What are some antiviral drugs used?
Nucleoside inhibitors
Non-nucleoside reverse transcription inhibitors
Protease inhibitors
Integrase inhibitors
What are some side effects of nucleoside reverse transcriptase inhibitors?
Marrow toxicity, neuropathy and lipodystrophy
What are some side effects of non-nucleoside reverse transcriptase inhibitors?
Skin rashes, hypersensitivity, drug interactions and neuropsychiatric effects
What are the side effects of protease inhibitors?
Drug interactions, diarrhoea, lipodystrophy and hyperlipidaemia
What are the side effects of integrase inhibitors?
Rashes and disturbed sleep
What is the treatment for lipodystrophy?
Change drugs
Cosmetic - facelift, liposuction and fillers
What are some challenges of HIV care?
Osteoporosis, cognitive impairment, malignancy, cerebrovascular disease, renal disease, ischaemic heart disease and DM
What is used for prevention of HIV?
Behaviour change and condoms
Circumcision
Treatment as prevention
Pre-exposure prophylaxis
Post-exposure prophylaxis for sexual exposure
