HIV Flashcards
Estimated # of HIV infections each year
56000
Most likely source of human infection was from _______
nonhuman primates
HIV
retrovirus. RNA virus. Cannot replicate unless it is in a living cell. It infects human cells that have CD4+ receptors on their surfaces, including lymphocytes, monocytes/macrophages, astrocytes, and oligodendrocytes. Immune dysfunction is caused predominantly by destruction of CD4+ T cells (T helper cells).
Major concern of the immune suppression in HIV
Development of opportunistic diseases
Specific conditions allowing transmission of HIV
Contact with infected blood, semen, vaginal secretions, and breast milk
When can an HIV infected individual transmit HIV to others?
Within a few days of becoming infection. The ability to transmit it is lifelong.
Blood transfusions as a source of HIV infection
They are not a significant source. Each unit of donated blood is tested. Only recipients who had a blood transfusion before 1985 are at significant risk for infection via the blood supply.
It is possible for a contaminated unit of blood to test negative for HIV if the donor has not yet formed antibodies to the virus at the time of donation.
Clinical manifestations of acute HIV infection
HIV-specific antibodies are produced and a mononucleosis-like syndrome of fever, lymphadenopathy, pharyngitis, headache, malaise, nausea, and/or a diffuse rash may occur.
When do symptoms generally occur with acute HIV infection?
2 to 4 weeks after initial infection and last for 1 to 2 weeks. During this time a high viral load is noted and CD4+ T cell counts fall temporarily but quickly return to baseline. Often mistaken for a bad case of the flu.
When does HIV antibody test become positive?
Median delay of 2 months after infection before antibodies can be detected.
Clinical manifestations of early chronic HIV infection
The median interval between untreated HIV infection and a diagnosis of AIDS is about 11 years. During this time, CD4+ lymphocyte count remains about 500 cells/uL, and the viral load in the blood is low. This is referred to as the asymptomatic phase, but fatigue, headache, low-grade fever, night sweats, persistent generalized lymphadenopathy (PGL), and other symptoms often occur.
Clinical manifestations of intermediate chronic HIV infection
When the CD4+ T cell count drops below 200 to 500 cells/uL, and the viral load increases, HIV advanced to a more active stage. Symptoms include persistent fever, frequent drenching night sweats, chronic diarrhea, headaches, and fatigue. Other problems include localized infections, lymphadenopathy, and nervous system manifestations.
Clinical manifestations of late chronic HIV infection
AIDS diagnosis cannot be made until one of the following criteria is established: CD4+ cell count <200/uL, opportunistic infection developed, opportunistic cancer (Kaposi sarcoma, etc), wasting syndrome (loss of 10% or more of ideal body mass), or development of AIDS dementia complex
Tests to diagnose HIV
Highly sensitive enzyme immunoassay detects serum antibodies that bind to HIV antigens,
Western blot (WB) or immunofluorescence assay (IFA) more specifically confirms HIV if a repeat EIA indicates the blood is HIV antibody positive,
Rapid HIV-antibody testing provides highly accurate screening results within 20 minutes. Positive results are then confirmed by WB or IFA.
Progression of HIV infection
CD4+ T cell count and viral load monitor the progression of the infection
White blood cell (WBC) count, red blood cell (RBC) count, and platelets decrease with progression of HIV
Treatment focus of HIV infection
(1) monitoring the disease progression and immune function, (2) initiating and monitoring antiretroviral therapy (ART), (3) preventing, detecting, and treating opportunistic diseases, (4) managing symptoms, (5) preventing or decreasing the complications of treatment, and (6) preventing further transmission of HIV
Antibody assay diagnostic test
Measures the immune system’s response from exposure to a specific antigen. Depends on antibody formation, but a pt’s serum may not have detectable levels of antibody during the initial stage of infection. Approximately 90% of the population forms antibodies in response to HIV within 3 weeks to 3 months after exposure, although this period can be as long as 6 months.
When can antibody testing be performed on an infant to check for HIV?
At 18 months when it becomes reliable.
Enzyme-Linked Immunosorbent Assay (ELISA) test
Highly specific test that is close to 99.6% sensitive for HIV-1 antibodies. False-positive tests may occur from recent flu or hep B vaccines, in multiparous women, after multiple blood transfusions, or with multiple myeloma, alcoholic hepatitis, or biliary cirrhosis.
Western Blot test
Positive ELISA test is confirmed by this test. It tests for antibodies to four major HIV antigens, two of which must be present for a positive result.
Viral load test
It is measured periodically in HIV-positive persons to assess their disease progression and to monitor the effectiveness of antiretroviral therapy. Therapy is aimed at reducing plasma HIV RNA levels to below the limit of detection by assay.
What does it mean when HIV RNA levels are suppressed below the level of detection?
HIV infection has not been eliminated, nor has viral replication been halted completely. It means that HIV levels have been reduced to such a degree that they cannot be measured by present methods.
CD4 cell count test
Measures the extent of immune damage that has occurred, and monitors the immunologic benefits of antiretroviral therapy. They are obtained on all newly diagnosed pts to establish a baseline and every 3 to 4 months thereafter if counts are above 350/mm3 and the pt is asymptomatic and not receiving drug therapy. Once drug therapy is initiated, counts are monitored every 2 to 4 weeks initially and then every 3 to 4 months if the pt stabilizes.
CD4 cell counts in conjunction with viral load
Predicts the possibility of disease progression, determines when to start antiretroviral therapy, and monitors the effectiveness of treatment. Pts with plasma HIV RNA levels less than 7000 copies/mL and CD4 counts of greater than 350 have less than 2% likelihood of progressing to AIDS within 3 years without treatment. Those with viral loads greater than 55,000 and CD4 counts less than 200 have an 85% chance of progressing to AIDS within 3 years.
Goal of HIV nursing management
Pt will adhere to drug regimens; promote a healthy lifestyle that includes avoiding exposure to additional sexual and blood-borne diseases; protect others from HIV; maintain or develop healthy and supportive relationships; maintain activities and productivity; explore spiritual issues; come to terms with issues related to disease, disability, and death; and cope with the frequent symptoms caused by HIV and its treatments.
Mainstay of HIV treatment
A highly active antiretroviral therapy “cocktail”. a protease inhibitor and two reverse transcriptase inhibitors.
Goals of drug therapy in HIV infection
Decrease viral load, maintain or raise CD4+ T cell counts, and delay the development of HIV-related symptoms and opportunistic diseases.
Prophylactic interventions to prevent opportunistic diseases
Pneumococcal, influenza, and hep B vaccines, trimethoprim-sulfamethoxazole inhalation for Pneumocystis jiroveci and toxoplasma, and rifabutin (Mycobutin) for Mycobacterium avium complex.
Wasting syndrome
In AIDS pts, especially late in the disease. Involuntary weight loss in excess of 10% to 15% of normal baseline weight. High-calorie, high-protein diet encouraged.
Nurses duty to warn
Clinicians may be required to report to the state partners of HIV-infected persons, even if the pt refuses to report the partner,
Clinicians may be required to disclose to third parties a high risk for future HIV transmission from pts known to be infected.
