Immunity Class 4 - Fall 2024 PDF

Immunity Exemplars: Human Immunodeficiency Virus (HIV) / Acquired Immune Deficiency Syndrome (AIDS) Fall 2024 Rebecca Jones MN, RN, GNC(C), LC History of HIV HIV infection in humans came from a type of chimpanzee in Central Africa – Studies show that HIV may have jumped from chimpanzees to...

Immunity Exemplars: Human Immunodeficiency Virus (HIV) / Acquired Immune Deficiency Syndrome (AIDS) Fall 2024 Rebecca Jones MN, RN, GNC(C), LC History of HIV HIV infection in humans came from a type of chimpanzee in Central Africa – Studies show that HIV may have jumped from chimpanzees to humans as far back as the late 1800s Likely passed on to humans when humans hunted these chimpanzees for meat and came in contact with their infected blood Over decades, HIV slowly spread across Africa and later into other parts of the world The HIV epidemic in Canada and the United States began in the early 1980s In 1981, public health officials documented presence of new disease known as acquired immune deficiency syndrome (AIDS) In 1985, the causative agent, HIV, was identified and AIDS was determined to be the end stage of HIV History of HIV Antibody test was developed Routes of transmission were determined 1987 à medication therapy to treat the infection became available 1994 more advances made à laboratory tests to assess viral load, combination mediation therapy, ability to test for antiretroviral resistance, treatment to decrease risk of transmitting infection from mother to baby, pre-exposure prophylaxis in high risk individuals, and using treatment as prevention However… Although great progress has been made, the HIV epidemic is not over Significance of the Problem In 2018, 62,050 individuals living with HIV in Canada – Numbers continue to increase due to ongoing transmission and increased longevity Major mode of transmission is through heterosexual sex, and women and children bear a large part of the burden of illness HIV infection remains a disease of marginalized individual 2024 Global AIDS Update Fewer people acquired HIV in 2023 than at any point since the late 1980s* Almost 31 million people were receiving lifesaving antiretroviral therapy in 2023, a public health success that has reduced the numbers of AIDS-related deaths to their lowest level since the peak in 2004. Globally, about 39% fewer people acquired HIV in 2023 compared with 2010 Nonetheless, an estimated 1.3 million people acquired HIV in 2023 https://crossroads.unaids.org/ Why is monitoring important? UNAIDS’ modelling suggests that achieving these targets by 2020 will enable the world to eliminate the AIDS epidemic by 2030 HIV à AIDS HIV – a virus that attacks our own immune system – Attacks our immune system so destructively that it puts you into a state of immune system failure – Unable to fight off even basic infections – Immuneless state HIV increases risk of infections that a healthy immune system could easily fend off If we don’t treat HIV à AIDS Excellent Overview of HIV/AIDS Transmission HIV – a fragile virus Transmitted only through contact with body fluids – Blood, semen, rectal fluids, vaginal secretions, and breast milk Modes of transmission: – Sex with an infected partner (most common) – MSM highest risk population (20x more likely in North America) – Exposure to HIV infected blood – Needle use – Blood transfusion – Occupational exposure – Perinatally at the time of delivery – Breastfeeding Transmission HIV-infected individuals can transmit HIV to others within a few days after becoming infected After that, the ability to transmit HIV is lifelong Sexual Transmission Most common form of transmission* Sexual activity involves contact with semen, vaginal secretions, blood (or a combination of all), which all have lymphocytes that may contain HIV During any form of sexual intercourse, the person who is receiving the semen has the greater risk (although vice versa also possible) Sexual activities that cause trauma = increase risk of transmission Genital lesions from STIs present = increase risk of transmission Pathophysiology of HIV What type of virus is HIV? T-lymphocytes – important CD4 protein – important in the progression of HIV à AIDS Cells with CD4+ receptor sites are infected the most Completely alters how our immune system functions Pathophysiology of HIV Single stranded RNA retrovirus injects into T-helper cell Uses reverse transcriptase (HIV RNA is changed to HIV DNA) HIV DNA enters nucleus using an enzyme called integrase, becoming a permanent part of the cell’s genetic structure/our cell’s new DNA Makes copies creating “viral load” Viral load = amount of HIV in blood stream The more HIV in blood, the more CD4+ cells affected (destroyed) Don’t only lose affected CD4+ cells, cells nearby destruct as well – When exposed to something requiring immune response (e.g. infection) immune cells transcribe and translate new HIV viruses Pathophysiology of HIV Immune problems start when CD4+ T-cell counts drop to below ______ cells/mcL. – What is the normal range? Allows for opportunistic diseases Opportunistic diseases are the main cause of disease, disability & death in HIV infection Clinical Manifestations Stage 1 – Acute Infection Person gets infected with HIV – gets into the WBCs ++ fast Hijacks our helper T-cells and many new HIV cells form The more HIV = the more CD4 cells that get attacked Self-destruct – destroys CD4 cells and other immune cells nearby Transmission is more likely when viral load is high – A huge viral load early on in the infection à easier to pass the infection onto someone else Clinical Manifestations Stage 1 – Acute Infection S&S: – Flu-like symptoms – Fever, swollen lymph glands, sore throat, headache, malaise, nausea, muscle and joint pain, diarrhea, open sores in mouth, or a diffuse rash – These symptoms are called acute retroviral syndrome and occur about 1–3 weeks after infection. Lasts for 1–2 weeks Body will start to get a handle on things, viral load will decrease as CD4 cells have a chance to recover Development of HIV-specific antibodies occurs (seroconversion) Clinical Manifestations Stage 2 - Early Chronic Infection Latency period/Chronic HIV When the viral load and CD4 count start to even out – HIV is still destroying CD4+ T cells but thymus and bone marrow are able to produce enough CD4+ T cells to replace destroyed cells Body has developed antibodies against HIV Generally asymptomatic or very minimal symptoms – often called “asymptomatic stage” Most patients are not aware of infected status, but they are *still infectious* Prolonged period (years) of low viral load Median timeline between untreated HIV and AIDS is 10 years Clinical Manifestations Stage 2 – Intermediate Chronic Infection CD4+ T cell count less than 500 cells/mcL but > 200 cells/mcL Viral load is rising HIV advances to more active stage Symptoms from earlier stages may worsen – May have persistent fever, frequent drenching night sweats, chronic diarrhea, recurrent headaches, and fatigue May have localized infections, lymphadenopathy, nervous system manifestations Most common infection with this phase is oropharyngeal candidiasis Intermediate chronic symptoms Oropharyngeal candidiasis (thrush) Shingles Oral hairy leukoplakia Persistent vaginal candida infections Herpes Bacterial infections Kaposi’s sarcoma (KS) Oropharyngeal Candidiasis Kaposi’s Sarcoma Oral Hairy Leukoplakia Clinical Manifestations Late Chronic Infection or AIDS Immune system severely compromised As disease progresses, T cell count decreases and viral load increase No functional immune system = AIDS Great risk for opportunistic disease Significant weight loss à increased energy use + decreased absorption of food Possible malignancies, wasting, and dementia Diagnosis of AIDS A diagnosis of AIDS cannot be made until the HIV infected person meets definition criteria 2 criteria need to be met: Do we know what they are? AIDS-Defining Illness It is the serious complications of these infections that cause the death of the person Organisms that don’t occur in functioning immune system can cause severe, debilitating, disseminated and life-threatening infections during advanced stage chronic HIV infection Several opportunistic diseases may occur at the same time, further compounding the difficulties of diagnosis and treatment Common example – Fungal Pneumonia, pneumocystis pneumonia, cryptococcus pneumonia, candidiasis of the esophagus, Kaposi sarcoma tumor/lesions Advances in HIV treatment have led to decreases in opportunistic diseases because successful treatment maintains a functioning immune system Diagnosing HIV Diagnosing HIV can be a real challenge Not really able to diagnose based on symptoms Feels like “really bad flu”, “feeling run down” This is why we require blood tests to be done that look for HIV antibodies or pieces of HIV in blood Diagnostics Detecting HIV antibodies in the blood Don’t forget it can take 1 month (or longer) to make HIV antibodies and two months (or longer) to be able to detect them This creates a window period where an infected individual will not test HIV antibody positive* Blood test: HIV antigen test – Looks for pieces of HIV virus in blood – These tests are referred to as ELISA (Enzyme Linked Immunosorbent Assay) tests Diagnostics If ELISA is positive, we do more testing – If ELISA is negative – 99.9% chance no – First, we repeat HIV at that time – Certain things such as lupus and – Review this individual’s risk history, syphillis can (rarely) cause positive tests particularly past several weeks. If high risk, recommend repeat labs at If still positive, a Western Blot or 3 weeks, 6 weeks & 6 months Immunofluorescence assay is done – Western Blot – Looks for presence of specific proteins on viral envelope – Immunofluorescence assay (IFA)- Detects HIV antibodies using a special fluorescent dye Diagnostics ELISA is positive x 2 + WB or IFA positive = HIV positive ELISA is positive + WB or IFA negative = looks at other causes for + ELISA – Review thorough history /risk assessment and 3 month history of high risk activities. – Not high risk – repeat testing 3 months – High risk activities – repeat at 1, 2 & 6 months Diagnostics Rapid Testing also available – Swab inside mouth or finger prick – Look for antibodies of p24 protein – Results in 20 mins – Less accuracy – Good at true negative but may miss positives Lab Monitoring Progression monitored by CD4+ T-cell counts Viral load – Helps determine: – When to initiate therapy? – Efficacy of therapy – Whether clinical goals are being met Abnormal blood tests common – Neutropenia (often seen), thrombocytopenia, and anemia – Altered liver function tests – May be caused by disease processes or drug therapy Look for co-infection – E.g. Hepatitis B or C Interprofessional Care Focuses on: – Monitoring HIV disease progression and immune function – Initiating and monitoring ART – Preventing the development of opportunistic diseases – Detecting and treating opportunistic diseases – Managing symptoms – Preventing or decreasing the complications of treatment – Providing comprehensive psychosocial and spiritual care Ongoing assessment and supportive health care provider–patient interactions are essential* Interprofessional Care Initial Visit – Gather baseline data – Complete history & physical – Immunization history – Psychosocial evaluations – Identify barriers to optimal care – What are some examples? Education – What would we educate on? – Considerations? How should this information be given? Medication Therapy Main goals 1. Decrease viral load 2. Maintain or raise CD4+ counts 3. Delay HIV-related symptoms and opportunistic infections 4. Prevent transmission HIV cannot be cured, but ART can decrease viral replication and delay progression of disease in most patients When taken consistently and correctly, ART can reduce viral loads by 90- 99%, which makes adherence to treatment regimens extremely important Antiretroviral Therapy Treatment – helps individuals live longer and healthier Six types of medication used in combination – typical treatment regimen include 2 or 3 of these regimens simultaneously Using a combination of medications à slow HIV replication and help immune system recover and fight off other infections Can stop people from getting really sick Can reduce levels of HIV to almost undetectable levels resulting in very low transmission rates (viral load is low!) Antiretroviral Therapy ART – Key Points Treatment should be started immediately upon diagnosis, regardless of CD4+ T-cell counts The most effective strategy à simultaneous initiation of at least 3 effective antiretroviral medications from at least 2 different medication classes in optimum schedules and full dosages Infected women should receive optimal ART even if pregnant HIV-infected persons with viral loads above detectable limits should be considered infectious and should avoid behaviors associated with transmission of HIV and other infectious pathogens Recommendations for starting therapy in infected patients have become much more simple in recent years. Treatment is now recommended for everyone, regardless of CD4 count, viral load, or pregnancy status ART Therapy Treatment protocols reduce viral load 90-99% but not without issue Many clients unable to use combination therapy because of: – Expense – Side effects – Treatment regimen – Dietary changes Currently medications are in pill form in Canada and require being taken at least once daily Long acting injectable options are becoming available Medication Therapy for Opportunistic Infections Management of HIV is complicated by the many opportunistic diseases that can develop as the immune system deteriorates Prophylactic medication given to prevent these opportunistic infections from occurring – E.g. Varicella Zoster, influenza, Hep A, Hep B, pneumococcal vaccines Post Exposure Prophylaxis (PEP) Intended for HIV Negative person who thinks they may have been exposed to HIV within the past 72 hours. Combination of three HIV medication that need to be taken daily x 4 weeks Medication taken to prevent getting HIV Reduces risk of getting HIV from sex by about 99% Reduces risk of getting HIV from IV drug use by at least 74% Must be started within 72 hours of exposure Nursing Management - Assessment To help in assessing risk, ask four basic questions 1. Received blood transfusion or clotting factors before 1985? 2. Shared needles, syringes, or other injection equipment with another person? 3. Sexually active? 4. History of sexually transmitted infection (STI)? A positive response to any of these questions requires a more in-depth exploration of the specified risk factor* Assessment Ongoing assessments required over time as circumstance changes A complete history and thorough systems review can help identify and address problems in a timely manner Early recognition and treatment can decrease the progression of HIV infection and prevent new infections Subjective and objective data that should be obtained - Table 17.15 (Lewis) Nursing Diagnosis See Table 17.16 for comprehensive list – can we think of any? Consider the following when thinking about applicable nursing diagnoses…dependent on many variables: – Stage – Is disease prevention the issue? – Are there concerns related to ongoing infection? – Is the patient terminal? – Presence of specific etiological problems – Respiratory distress – Depression – Wasting – Social factors – Issues related to self-esteem – Sexuality – Family interactions – Finances Planning Challenges for the client – many related to behavior change – Nurses can be instrumental here* Main goals: – Keep viral load low – Maintain immune function – Improve quality of life – Reduce potential for transmission (think about client’s individual risk factors) – Prevent opportunistic disease and new infections – Reduce disability – Prevent reinfection Implementation Interventions can assist patient to: – Adhere to medication regimens – Promote healthy lifestyle à maintain productivity – Prevent opportunistic diseases – Protect others – Have supportive relationships – Explore spirituality – Cope with symptoms and treatments – Come to terms with issues related to death and disability Individualized and change as new treatment protocols are developed and/or as HIV disease progresses Implementation HIV is a highly variable chronic disease. Primary prevention and health promotion are the most effective health care strategies Nursing interventions at every stage of HIV disease can be instrumental in improving the quality and quantity of the patient’s life See Table 17.17 (Lewis) Health Promotion Major goals: prevention of disease and early detection HIV is preventable à education and behavior change are most effective prevention tools Safer, healthier, and less risky behaviors These techniques can be divided into: 1. Safe activities (those that eliminate risk) 2. Risk-reducing activities (those that decrease, but do not totally eliminate, risk) Most new HIV infections were transmitted by individuals who were not aware that they were infected Prevention of HIV Decreasing risks: Sexual intercourse – Abstinence – Use of barriers – Anal & vaginal sex carry highest risk of transmission – Anal sex 10-20x higher risk – Receptive anal sex – highest risk for transmission – Only single layer of epithelial cells vs. layers in vagina and penis – Male condoms up to 100% effective in preventing HIV when used correctly – Female condoms Prevention of HIV Decreasing risks: Substance use – Do not use illegal or illicit substances – Do not share equipment – Do not have sexual intercourse under the influence of any impairing substance Prevention of HIV Decreasing risks: Perinatal transmission – Prevent HIV in women – Appropriately medicate HIV-infected pregnant women – Medication zidovudine decreases risk of passing HIV to child – If HIV-infected pregnant women are appropriately treated during pregnancy, the rate of perinatal transmission can be decreased from 25% to less than 1% – ART has significantly decreased the risk for infants born to HIV-infected women, and more of these women are now considering becoming mothers Prevention of HIV Decreasing risks: Work – Adhere to precautions and safety measures to avoid exposure – Postexposure prophylaxis with combination ART HIV Testing and Counseling Testing is the only sure method to determine infection – Negative results: opportunity for prevention education – Positive results: treatment and education to protect sexual and substance use partners All testing should be accompanied by pretest and post-test education as mandated by the WHO The goals are to normalize the test, decrease stigma related to HIV testing, find hidden cases, get infected individuals into care, and prevent new cases of infection Acute Intervention Early intervention promotes health and limits or delays disability Initial response to positive HIV test – Similar to any life-threatening, chronic illness – Ranges from immediate acceptance to grief, denial, and suicidal thoughts Empowerment ART Therapy – Multi-medication therapy can reduce viral load and disease progression – Many factors contribute to problems with adherence to treatment, a dangerous situation because of the high risk of developing drug resistance ART Therapy - Interventions Interventions include education about: – Advantages and disadvantages of new treatments – Dangers of poor adherence to therapeutic regimens – How and when to take each medication – Medication interactions to avoid – Adverse effects that must be reported to the health care provider When to start therapy? – All people with HIV should receive treatment regardless of their CD4+ T-cell count – Assess patient readiness – Treatment should be initiated at the time of diagnosis – Decreasing viral load leads to better health outcomes and less risk of transmission – Individualized decision Health Promotion Disease progression can be delayed by promoting a healthy immune system – Nutritional support – Moderation or elimination of alcohol – Adequate rest and activity – Stress reduction – Avoidance of exposure to new infections – Mental health counselling – Support groups and community activities Acute Exacerbations Recurring problems of infection, cancer, physical weakness, and psychosocial/economic issues affect the ability to cope Nursing care becomes more complex as the patient’s immune system deteriorates and new problems arise to compound existing difficulties When opportunistic diseases or difficult adverse effects of treatment develop, symptom management, education, and emotional support are necessary The best way to prevent opportunistic disease is to provide adequate treatment for the underlying HIV infection End of Life Care Focus: – Keeping the patient comfortable – Promoting emotional and spiritual acceptance of finite nature of life – Helping significant others deal with loss