HIV CASE STUDY Flashcards
WHAT IS HIV?
A retrovirus that attacks the immune system, specifically CD4+ T cells, which play a crucial role in immune defence.
TRANSMISSION AND PROGRESSION OF HIV:
Through unprotected sexual contact, blood transfusion, sharing needles and mother to child during childbirth.
If left untreated it can progress to AIDS, characterised by sever immune deficiency and increased susceptibility to opportunistic infections.
STAGES OF HIV:
- acute HIV infection after exposure: occurs after 2-4 weeks of exposure
symptoms: fever, sore throat, swollen lymph nodes, rash and mouth ulcers - chronic HIV infection: virus remains in the body at lower levels, no significant symptoms, but ongoing viral replication, this stage can last for years if ART is not taken
- AIDS: CD4 count drops below 200 cells/ul, increased vulnerability to opportunistic infections, without ART, AIDS can occur 10-12 years after initial infection
HOW IS HIV DIAGNOSED:
- HIV antigen/antibody test: detects antibodies or the HIV p24 antigen.
- viral load test: measures the amount of virus in the blood
- CD4 count: measure the immune function by counting CD4+ T cells
Rapid HIV test: provide quick results, used in clinical settings.
5 TYPES OF HIV TREATMENT:
- ART (Antiretroviral therapy): involves a combination of drugs that prevent viral replication, a typical regime includes 3 or more medication from at least 2 different classes.
- NNRTIs (non-nucleoside reverse transcriptase inhibitors): block reverse transcriptase
- PIs (Protease inhibitors): block viral protease, preventing maturation of virus particles
- INSIs (integrate strand transfer inhibitors): block the integrase enzyme, preventing viral DNA from integrating into the host genome
- entry inhibitors: block HIV from entering the CD4 cells
WHAT ARE THE KEY LAB VALUES IN IDENTIFYING HIV ?
- CD4+ T cells count: a low CD4+ T cell count indicates a risk of developing opportunistic effects
- viral load (measure of the amount of HIV in the blood): high viral load = uncontrolled HIV
- low Hb: consequence of HIV or ART drugs e.g. zidovudine
- Complete blood count: leukopenia (low blood cell indicative of immunosuppression)
lymphocytopenia (low lymphocyte count , common in advanced HIV) - Immunoglobulin levels: low IgG, IgA, IgM, indicate weakened immune response due to HIV
WHAT ARE OPPORTUNISTIC INFECTIONS IN HIV ?
- They occur when the immune system is too weakened by HIV to control infections that are not usually harmful
5 TYPES OF OPPORTUNISTIC INFECTIONS
- Pneumocystis jiroveci pneumonia (PCP):
- Candidiasis (oral and esophageal)
- tuberculosis (TB)
- Toxoplasmosis
- Cytomegalovirus (CMV)
- Cryptococcal Meningites
Pneumocytsis Jirovecii pneumonia (PJP)
A fungal infection of the lungs seen when CD4 count is <200. Patients present with dry cough, fever, and hypoxia. Diagnosis is by staining of respiratory samples, and treatment is with co-trimoxazole. Prophylaxis is recommended for high-risk patients.
Tuberculosis:
Caused by Mycobacterium tuberculosis, TB can occur at any CD4 level but becomes more disseminated and atypical with lower counts. Symptoms include chronic cough, night sweats, and weight loss. Treatment involves multiple antibiotics over at least 6 months.
Toxoplasmosis
A protozoal infection caused by Toxoplasma gondii, typically affecting the brain in immunocompromised individuals. CD4 <100 is a major risk factor. Presents with seizures, confusion, and focal neurological deficits. Treated with pyrimethamine, sulfadiazine, and folinic acid.
Cytomegalovirus (CMV)
A viral infection causing retinitis, colitis, or encephalitis, particularly in patients with CD4 <50. CMV retinitis can lead to blindness. Diagnosis involves PCR or ophthalmological exam, and treatment includes ganciclovir or valganciclovir.
Cryptococcal Meningitis
Caused by Cryptococcus neoformans, this fungal infection affects the central nervous system, especially when CD4 <100. Symptoms include headache, fever, and altered mental status. Diagnosis is via CSF analysis, and treatment includes amphotericin B and fluconazole.
ART Adherence strategies:
Adherence to antiretroviral therapy (ART) is critical for achieving viral suppression, improving immune function, and preventing resistance.
- Patient Education and Counselling:
Educating patients about the importance of adherence, how ART works, and the consequences of missed doses empowers them to take ownership of their treatment. - Addressing Side Effects:
Managing side effects through medication adjustments or supportive treatment can reduce drop-out due to discomfort or fear of adverse effects. - Regular Follow-up and Monitoring:
Frequent clinic visits help reinforce the importance of adherence and allow early detection of non-compliance, enabling timely interventions.
