HIV/AIDS Flashcards
Pathophysiology of HIV
- HIV destroys the body’s ability to fight infection.
- The virus infects cells that have the CD4 antigen. Once inside the cell, the virus sheds its protein coat and uses reverse transcriptase to convert the viral RNA to DNA. The viral DNA is then integrated into host cell DNA and duplicated during normal processes of cell division. The virus may remain latent or become activated to produce new RNA and to form virions. The virus then buds from the cell surface, disrupting the cell membrane and leading to destruction of the host cell.
Human Immunodeficiency Virus
A retrovirus (meaning that it carries its genetic information in RNA) that is transmitted by direct contact with infected blood and body fluids.
Virions
Virus able to grow and reproduce outside a host
Seroconversion
Antibodies are produced against the viral proteins. These antibodies usually are detectable 6 weeks - 6 months after the initial infection.
Children can acquire HIV by Vertical transmission:
Perinatal transmission- transplacentally or during delivery
- transmission can occur during birth from blood, amniotic fluid, and exposure to genital tract secretions and after birth from breast milk.
- Risk is significantly reduced when mothers receive Retrovir, AZT during pregnancy, and when deliveries are by cesarean section at 38 weeks gestation before rupture of membranes, and babies are given therapy after birth.
HIV is present in:
- Blood
- Semen
- Vaginal and Cervical secretions
- cerebrospinal fluid
- Breast milk
- Saliva
Etiology of HIV
- Men make up majority of cases
- Women account for 26%
- Higher incidence in African Americans and Hispanics
Risk Factors for HIV
Primarily behavioral
- Behavior- unprotected anal intercourse, injection drug use, heterosexual intercourse
- Hemophilia and blood transfusions- Those in the window period 6 weeks- 6 months are able to transmit HIV to others even though they do not yet test positive
- Health Care as an occupation
- Poverty- less access to preventive health care& education, increased illiteracy, less likely to have internet as a health tool
- Pregnancy and Breast feeding- smoking, illicit drug use, genital tract infections, and unprotected sexual intercourse
- Older Age- declining immune system, belief that they cannot be affected. fail to use condoms in non-child bearing years
Clinical Manifestations of HIV
Range from no symptoms at all to severe immunodeficiency with multiple opportunistic infections and cancers.
- Most develop acute, mononucleosis- type illness within days to weeks after contracting the virus.
a. Fever, sore throat, arthralgias, myalgias, headache, Rash, Nausea vomiting, abdominal cramping, and lymphadenopathy. - Many attribute this initial manifestations to a common viral illness such as influenza.
- After acute illness, clients enter a long-lasting asymptomatic period, which can last from 8-10 years.
- Some develop persistent generalized lymphadenopathy (enlargement of 2 or more lymph nodes for more than 3 months)
- Client then experiences: General malaise, fatigue, low-grade fever, night sweats, involuntary weight loss, dry skin, rashes, diarrhea, oral lesions
- Development of advanced HIV occurs around 10-11 years after initial infection
Classification System for HIV Infection
CD4 Counts
(1) = 500/mm3
(2) = 200-400/mm3
(3) = <200/mm3
Classification System for HIV Infection
Category A
- Asymptomatic HIV infection
- Persistent generalized lymphadenopathy
- Acute HIV infection w/ illness or history of acute HIV infection
Classification System for HIV Infection
Category B
- Symptomatic
- Candidiasis, oral thrush
- cervical dysplasia/ cervical carcinoma in situ
- Fever, diarrhea exceeding 1 month
- Hairy leukoplakia
- Herpes zoster involving at least 2 distinct episodes
- Peripheral neuropathy & Pelvic inflammatory disease
Classification System for HIV Infection
Category C
AIDS-Indicator Categories
- Candidiasis of bronchi, trachea, lungs, or esophagus
- Kaposi’s sarcoma
- Cryptococcosis
- HIV encephalopathy
Antiretroviral Therapies
stop or suppress activity of retrovirus, preventing further weakening of the immune system and thereby minimizing opportunistic infections
Pneumocystis carinii pneumonia (PCP)
- An opportunistic infection that is not pathogenic in those with intact immune systems
- CD4 count is < 200/mm3
- most commonly in those who are undiagnosed, have a late HIV infection, or fail to take prophylactic antibiotics.
- S/S fever, cough, dyspnea, tachypnea, & tachycardia
- Cause of death in 20% of clients w/ AIDS
AIDS Dementia complex
- Most common cause of mental status change for clients with HIV infection.
- results from direct effect of the virus on the brain and impacts cognitive, motor,and behavioral functioning. Fluctuating memory loss, confusion, difficult concentrating, lethargy, and diminished motor speed are typical manifestations.
- clients become apathetic, losing interest in work, social and recreational activities.
Toxoplasmosis
Toxoplasmosis and non-Hodgkin’s lymphoma are space-occupying lesions that may cause headache, altered mental status, and neurologic deficits.
Opportunistic Infections
- most common manifestations of AIDS and often occur simultaneously
- Risk is predictable by T4 or CD4 cell count.
- Normal CD4 is > 1000/mm3.
- When CD4 falls below 500/mm3 immunodeficiency s/s develop
- When CD4 is less than 200/mm3 opportunistic infections & cancers are likely.
Tuberculosis
- active TB results from reactivation of a previous infection, or a new primary disease facilitated by impaired immune function
- Rapid progression, diffuse pulmonary infiltrates, and disseminated disease occur more commonly in clients with AIDs
Candidiasis
- opportunistic fungal infection
- usually manifests as oral thrush or esophagitis
- Often is 1st indication of progression to AIDS
- Esophagitis-> difficulty swallowing, substernal pain or burning
- In women vaginal candidiasis is frequent and often recurrent
Mycobacterium Avium complex
- Typically occurs late in course of disease, when CD4 cell counts are less than 50/mm3
- More common in women than men
- caused by organisms found in food, water, and soil
- Major cause of “wasting syndrome”
- S/S: chills, fever, weakness, night sweats, abd pain, diarrhea, weight loss
CDC classification of AIDS currently includes 4 Cancers:
- Kaposi’s Sarcoma
- Two lymphomas: non-Hodgkin’s & Primary lymphoma of the brain
- invasive cervical carcinoma
Kaposi’s Sarcoma
- Often the presenting symptom of AIDS
- Most common cancer associated with the disease
- virus called KS-associated herpes virus aka human herpesvirus 8
- Survival time after diagnosis is 18 months
- A tumor of the endothelial cells lining small blood vessels, KP presents as vascular macules, papules, or violet lesions affecting the skin and viscera.
Lymphomas
- Malignancies of the lymphoid tissue, including lymphocytes, lymph nodes, and lymphoid organs, such as the spleen and bone marrow.
- CNS is usual site for lymphoma, but also found in bone marrow, GI tract, liver, skin, and mucous membranes.
- headache & change in mental status- early s/s
Cervical Cancer
- Of women infected with HIV 40% have cervical dysplasia
- tends to be aggressive
- women with concurrent HIV infection and cervical cancer usually die of cervical cancer not AIDS
- Recommended women with HIV have Pap smears ever 6 months
Goals of care for HIV
- Early identification of the infection
- Promoting health maintenance activities to prolong the asymptomatic period
- Prevention of opportunistic infections
- Treatment of disease complications, such as cancers
- Providing emotional and psychosocial support
HIV Test Trends:
False positive HIV test results are more likely in settings where the tested population prevalence is lower than in settings where the tested population prevalence is higher.
Rapid Diagnostic Tests
- Enzyme-linked immunosorbent assay (ELISA)
- Western blot antibody testing
- HIV viral load tests
- CBC- anemia, leukopenia, thrombocytopenia
- CD4 count
Enzyme-linked immunosorbent assay (ELISA)
- most widely used
- tests for HIV antibodies not the virus itself, client may be negative early in course of infection, before detectable antibodies have developed.
- 99.5 sensitivity when preformed 13 weeks after infection
- Initial (+) is always tested repeatedly and confirmed using a different method, usually Western Blot
Western blot antibody testing:
- more reliable than ELISA, more time consuming, and expensive
- when combined with ELISA a specificity of 99.9%
- Client’s serum is mixed with HIV proteins to detect a reaction. If antibodies are present a detectable antigen-antibody response will occur
HIV viral load tests:
- Measure amount of actively replicating HIV
- levels correlate with disease progression
- levels greater than 5,000-10,000 indicated need for treatment
CBC
- to detect anemia, leukopenia, and thrombocytopenia often present in HIV infection
CD4 Cell count:
- most widely used test to monitor progress of disease and to guide therapy
- correlates closely with immunodeficiency disorders seen in clients with AIDS
- AIDS is defined not only by presence of opportunistic infections and other diseases but also by HIV seropositive status and CD4 count less than 200/mm3
- Recommended every 3-6 months for HIV clients
Other Diagnostics:
- Blood culture for HIV- most specific, expensive, cumbersome
- Immune-complex-dissociated p24 assay- test for p24 (HIV) antigen in the blod
- TB skin testing
- MRI of brain
- Pap smears every 6 months
Pediatric Testing:
- ELISA and Western Blot cannot distinguish between maternal and infant antibodies. May take up to 18 months for infected infants to form their own antibodies to HIV.
- Testing By HIV DNA polymerase chain reaction (PCR) is the preferred test.
- Test at 1-2 months then again at 2-4 months, considered infected if 2 separate samples are positive
Highly active antiretroviral therapy (HAART)
- uses a minimum of 3 antiretroviral agents
- generally includes: zidovudine (Retrovir, AZT), an NRTI, plus a second NRTI, such as didanosine or lamivudine, combined with a nonnucleoside reverse transcriptase inhibitor (NNRTI), such as nevirapine, or a protease inhibitor (PI) such as indinavir, ritonavir, or saquinavir
4 classes of drugs used in antiretroviral treatment:
- Nucleoside Reverse Transcriptase Inhibitors (NRTIs)
- Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs)
- Protease Inhibitor (PI)
- Entry Inhibitors
HAART combines 3 out of 4 to reduce the incidence of drug resistance.
Nucleoside Reverse Transcriptase Inhibitors (NRTIs)
- inhibit action of viral reverse transcriptase, a retroviral enzyme that catalyzes the substrates for conversion and copying of viral RNA to DNA sequences
- Zidovudine (AZT)-1st antiretroviral agent approved for use with HIV infection. often is given to clients with a CD4 <500/mm3 because it slows progression to severe disease
Protease Inhibitors
- bond chemically with protease to block the function of the enzyme and result in the production of immature, noninfectious viral particles
- PIs may inhibit metabolism of other meds, and cause them to circulate longer.
- elevated cholesterol, triglycerides, insulin resistance, and diabetes, changes in body fat composition.
- Saquinavir (Invirase), Ritonavir (Norvir),
Nonnucleoside Reverse Transcriptase Inhibitors (NNRTIs)
- Nevirapine
- high incidence of cross resistance to NRTIs
- risk of liver toxicity and Stevens-Johnson syndrome
Entry Inhibitors
- efuvirtide (Fuzeon)
2. prevent HIV from entering target cells by binding to protein envelope that surrounds the virus.
Vaccines for HIV clients
- Pneumococcal, influenza, Hep. B,
- Persons w/ positive PPD and negative chest x-ray are given prophylactic isoniazid
- CD4 <100/mm3= prophylactic for MAC
Complementary Therapies
- warnings against use of garlic supplements w/HIV meds
2. St. John’s wort also contraindicated for clients receiving antiretroviral therapy.
Nursing Diagnosis for HIV
- Ineffective coping
- Impaired Skin Integrity
- Imbalanced nutrition: less than body requirements
- Risk for deficient fluid volume
- risk for infection
- anxiety
- fear
- deficient knowledge
Safe Sex practices:
- Use latex condoms
2. nonoxynol-9 a spermicide, may cause genital ulcers
Cleaning paraphernalia
use a fresh solution of houshold bleach and water 1:10 ratio
