Summary
Highlights
HIV (Human Immunodeficiency Virus) attacks the body's immune system, specifically CD4 positive cells like helper T cells, macrophages, monocytes, and dendritic cells. Helper T cells are vital for fighting infection, but HIV hijacks and kills them, leading to opportunistic infections (OIs) when their count drops. AIDS (Acquired Immunodeficiency Syndrome) is the final stage of HIV. There is no cure for AIDS, but Antiretroviral Therapy (ART) can improve CD4 counts and extend life. As of late 2020, 37.7 million people were living with HIV globally.
HIV transmission depends on the viral load, type of contact, and the immune system of the exposed person. It is transmitted through blood, semen, vaginal fluid, and breast milk, entering the bloodstream via injury or mucous membranes. High-risk activities include unprotected sexual contact, sharing needles, contaminated blood transfusions, needle stick injuries, and mother-to-child transmission during pregnancy, birth, or breastfeeding. HIV is not transmitted through casual contact like hugging, closed-mouth kissing, sweat, tears, or insect bites.
HIV, a retrovirus, cannot multiply without a host cell. It targets CD4+ cells, especially helper T cells, which are crucial for adaptive immunity. The virus attaches to the CD4 receptor using its gp120 glycoprotein, fuses with the cell, and injects its contents (RNA and enzymes like reverse transcriptase, integrase, and protease). Reverse transcriptase converts viral RNA into double-stranded DNA, which integrase then inserts into the host cell's DNA. The cell then replicates viral components, which assemble and bud off, mature with the help of protease, and then kill the host cell, repeating the cycle. Understanding this cycle is vital for comprehending how ART works.
HIV infection progresses through three stages: acute, chronic, and AIDS. The acute stage (2-4 weeks post-infection) involves flu-like symptoms and a high viral load, making transmission easy. Testing may yield false negatives if performed too early due to the window period for seroconversion. The chronic stage is often asymptomatic with a lower viral load, but the virus is still active. CD4 counts are typically 200-500 cells/mm³. Progression to AIDS occurs when the viral load increases, symptoms reappear, and opportunistic infections develop. AIDS is diagnosed with a CD4 count below 200 cells/mm³ or the presence of OIs. Without medication, survival in the AIDS stage is short.
Patients with advanced HIV are prone to various opportunistic infections: Cancerous (Kaposi's sarcoma), Viral (Cytomegalovirus, Epstein-Barr virus causing oral hairy leukoplakia, Herpes Simplex Virus), Bacterial (Mycobacterium tuberculosis, Salmonella septicemia, Mycobacterium avium complex, Streptococcus pneumoniae), Fungal (Candidiasis, Coccidioidomycosis, Cryptococcosis, Histoplasmosis, Pneumocystis Pneumonia), and Protozoal (Toxoplasmosis, Cryptosporidiosis, Cystoisosporiasis).
To prevent opportunistic infections, HIV-positive patients should drink treated water, eat fully cooked and pasteurized foods, avoid high-risk sexual and drug activities, keep vaccinations (like pneumovax) up to date, limit exposure to animal feces (especially from birds or cats), and consistently take their ART medications to maintain a strong immune system.
Nurses play a critical role in screening patients for HIV risk, educating them about the disease, and monitoring their treatment. Screening involves asking about sexual behavior, drug use, and history of blood transfusions. The CDC recommends yearly testing for high-risk individuals and at least one test between ages 13-64. Nurses also educate about PrEP (pre-exposure prophylaxis) for those at high risk but HIV-negative, and PEP (post-exposure prophylaxis) for emergency post-exposure situations. For HIV-positive individuals, education focuses on preventing transmission, sexual health, safe practices, and managing pregnancy to prevent mother-to-child transmission through ART.
ART aims to limit viral replication by interfering with the HIV life cycle, decreasing viral load (ideally within six months) and increasing CD4 levels (above 500) to prevent OIs. ART involves a combination of three medications from at least two drug classes. These classes target different stages of the HIV life cycle: attachment inhibitors (e.g., trogarzo, reucovia), entry inhibitors (e.g., maravaroc, infuvertide), non-nucleoside reverse transcriptase inhibitors (e.g., dravarine), nucleoside/nucleotide reverse transcriptase inhibitors (e.g., abacavir), integrase inhibitors (e.g., raltegravir), and protease inhibitors (e.g., atazanavir). Adherence to the medication regimen is crucial to prevent drug resistance and maintain treatment effectiveness. Nurses must assess patient adherence, financial accessibility, and potential drug interactions, especially with herbal remedies like St. John's Wort.