NUR302 - Ch. 37: Management of Patients With HIV Infection and AIDS

As part of HAART therapy, a client is prescribed a non-nucleoside reverse transcriptase inhibitor (NNRTI). Which of the following would be an example of a drug from this class? Select all that apply.

- Delavirdine - Efavirenz Examples of NNRTIs are delavirdine and efavirenz. Abacavir and stavudine are nucleoside reverse transcriptase inhibitors (NRTIs). Amprenavir is a protease inhibitor.

The development of a positive HIV antibody test following initial infection generally occurs in which timeframe?

4 weeks Development of a positive HIV antibody test generally occurs within 4 weeks and with few exceptions by 6 months.

When do most perinatal HIV infections occur?

After exposure during delivery Mother-to-child transmission of HIV-1 may occur in utero or through breastfeeding, but most perinatal infections are thought to occur after exposure during delivery.

A patient with AIDS informs the nurse of difficulty eating and swallowing, and shows the nurse white patches in the mouth. What problem related to AIDS does the nurse understand the patient has developed?

Candidiasis Candidiasis, a fungal infection, occurs in almost all patients with AIDS and immune depression (Durham & Lashley, 2010). Oral candidiasis is characterized by creamy-white patches in the oral cavity and, if left untreated, can progress to involve the esophagus and stomach. Associated signs and symptoms include difficult and painful swallowing and retrosternal pain.

Which microorganism is known to cause retinitis in people with HIV/AIDS?

Cytomegalovirus Cytomegalovirus is a species-specific herpes virus. C. neoformans is a fungus that causes an opportunistic infection in clients with HIV/AIDS. M. avium is an acid-fast bacillus that commonly causes a respiratory illness. P. carinii is an organism that is thought to be protozoan, but believed to be a fungus based on its structure.

When assisting the client to interpret a negative HIV test result, the nurse informs the client that the results mean that

the body has not produced antibodies to the AIDS virus. A negative test result indicates that antibodies to the AIDS virus are not present in the blood at the time the blood sample for the test is drawn. A negative test result should be interpreted as demonstrating that if infected, the body has not produced antibodies (which takes from 3 weeks to 6 months or longer). Therefore, subsequent testing of an at-risk client must be encouraged. The test result does not mean that the client is immune to the virus, nor does it mean that the client is not infected. It just means that the body may not have produced antibodies yet. When antibodies to the AIDS virus are detected in the blood, the test is interpreted as positive.

A client who is HIV+ has been diagnosed with Pneumocystis pneumonia caused by P. jiroveci. What medication will the client take for the treatment of this infection?

trimethoprim-sulfamethoxazole To prevent and treat Pneumocystis pneumonia, trimethoprim-sulfamethoxazole (Bactrim, Septra) is prescribed. The other medications are antifungals and used to treat candidiasis.

A client is considering beginning sexual relations and wants to know the best way to be protected from a sexually transmitted infection and HIV. What is the best response by the nurse?

"Using a condom (latex) and spermicidal jelly is one of the most effective ways to decrease the risk of transmission of an STI and HIV." Using a condom is one of the most effective ways to reduce the risk of HIV infection. Condoms are available for both men and women. A diaphragm would not be the most effective way because there is no protection for the penis or vagina. A lamb skin condom is not effective to prevent the transmission of HIV. Douching after intercourse is not an effective method to avoid transmission and does not offer protection from secretions that are already present.

A client who has AIDS reports having diarrhea after every meal, and wants to know what can be done to stop this symptom. What should the nurse advise?

Avoid fibrous foods, lactose, fat, and caffeine. Diarrhea may subside when the client avoids fibrous foods, lactose, fat, and caffeine. Although eating may seem to cause diarrhea, the client must understand that limiting the intake of food to control diarrhea only exacerbates wasting. The client will tolerate a low-fat, high-carbohydrate, and soft or liquid diet better than large, high-fat meals. The client should be advised to avoid large doses of iron and zinc because they can impair the functioning of the immune system.

Which of the following are antidepressants used in the treatment of AIDS? Select all that apply.

- Tofranil - Norpramin - Prozac Antidepressants such as Tofranil, Norpramin, and Prozac may be used, because these medications also alleviate the fatigue and lethargy that are associated with depression. Megace is an appetite stimulant. Mycelex is used for esophageal or oral candidiasis.

When assisting the patient to interpret a negative HIV test result, the nurse informs the patient that the results mean which of the following?

Antibodies to HIV are not present in his blood. A negative test result indicates that antibodies to HIV are not present in the blood at the time the blood sample for the test is drawn. A negative test result should be interpreted as demonstrating that if infected, the body has not produced antibodies (which take from 3 weeks to 6 months or longer). Therefore, subsequent testing of an at-risk patient must be encouraged. The test result does not mean that the patient is immune to the virus, nor does it mean that the patient is not infected. It just means that the body may not have produced antibodies yet. When antibodies to HIV are detected in the blood, the test is interpreted as positive.

A home care nurse is visiting a client with AIDS at home. During the visit, the nurse observes the caregiver providing care. Which of the following would alert the nurse to the need for additional teaching for the caregiver?

Caregiver cleans the client's anal area without wearing gloves To prevent the risk of HIV transmission, standard precautions should be used. Cleaning the client's anal area without wearing gloves indicates that the nurse needs to reinstruct the caregiver in measures related to standard precautions. Handwashing before and after client care, disposing of sharps in a puncture-resistant container, and cleaning up spills with a dilute bleach solution are appropriate measures.

Which condition is an early manifestation of HIV encephalopathy?

Headache Early manifestations of HIV encephalopathy include headache, memory deficits, difficulty concentrating, progressive confusion, psychomotor slowing, apathy, and ataxia. Later stages include hyperreflexia, a vacant stare, and hallucinations.

When assisting the client to interpret a negative HIV test result, what does the nurse tell the client that this result means?

The body has not produced antibodies to the AIDS virus. A negative test result indicates that antibodies to the AIDS virus are not present in the blood at the time the blood sample for the test is drawn. A negative test result should be interpreted as demonstrating that, if infected, the body has not produced antibodies (which takes from 3 weeks to 6 months or longer). Therefore, subsequent testing of an at-risk client must be encouraged. The test result does not mean that the client is immune to the virus, nor does it mean that the client is not infected. It just means that the body may not have produced antibodies yet. When antibodies to the AIDS virus are detected in the blood, the test is interpreted as positive.

A client asks a nurse, "What can I use to decrease my risk of exposure to HIV?" Which of the following would the nurse include as effective in reducing the risk of HIV exposure? Select all that apply.

- Sexual abstinence - Latex male condoms - Polyurethane female condoms - Dental dams Based on the evidence, abstinence is the most effective means of reducing the risk of HIV transmission. Additionally, consistent and current use of latex male condoms or polyurethane female condoms are effective in decreasing the risk of HIV transmission. Lambskin condoms do not protect against HIV infection. Dental dams should be used to reduce the risk of HIV exposure during oral contact with the vagina or rectum.

A client with AIDS has become forgetful with a limited attention span, decreased ability to concentrate, and delusional thinking. What condition is represented by these symptoms?

AIDS dementia complex (ADC) ADC, a neurologic condition, causes the degeneration of the brain, especially in areas that affect mood, cognition, and motor functions. Such clients exhibit forgetfulness, limited attention span, decreased ability to concentrate, and delusional thinking. DSP is characterized by abnormal sensations, such as burning and numbness in the feet and later in the hands. Candidiasis is a yeast infection that may develop in the oral, pharyngeal, esophageal, or vaginal cavities or in the folds of the skin. CMV infects the choroid and retinal layers of the eye, leading to blindness, and can also cause ulcers in the esophagus, colitis, diarrhea, pneumonia, and encephalitis.

A patient with HIV develops a nonproductive cough, shortness of breath, a fever of 101°F and an O2 saturation of 92%. What infection caused by Pneumocystis jiroveci does the nurse know could occur with this patient?

Pneumocystis pneumonia The most common life-threatening infection in those living with AIDS is Pneumocystis pneumonia (PCP), caused by P. jiroveci (formerly P. carinii) (Durham & Lashley, 2010). Without prophylactic therapy (discussed later), most people infected with HIV will develop PCP. The clinical presentation of PCP in HIV infection is generally less acute than in people who are immunosuppressed as a result of other conditions. Patients with HIV infection initially develop nonspecific signs and symptoms, such as nonproductive cough, fever, chills, shortness of breath, dyspnea, and occasionally chest pain. Arterial oxygen concentrations in patients who are breathing room air may be mildly decreased, indicating minimal hypoxemia.

Which statement reflects treatment of HIV infection?

Treatment of HIV infection for an individual client is based on the client's clinical condition, CD4 T cell count, and HIV RNA (viral load). Although specific therapies vary, treatment of HIV infection for an individual client is based on three factors: the patient's clinical condition, CD4 T cell count, and HIV RNA (viral load). Treatment should be offered to all clients with the primary infection (acute HIV syndrome). In general, treatment should be offered to clients with fewer than 350 CD4+ T cells/mm or plasma HIV RNA levels exceeding 55,000 copies/mL (RT-PCR assay).

Which diagnostic test measures HIV RNA in the plasma?

Viral load A viral load test measures the quantity of HIV RNA in the blood. Enzyme immunoassay (EIA) is a blood test that can determine the presence of antibodies to HIV in the blood or saliva; it is also referred to as an enzyme-linked immunosorbant assay (ELISA). A Western blotting assay is a blood test that identifies antibodies to HIV and is used to confirm the results of an EIA (ELISA) test.

What test will the nurse assess to determine the client's response to antiretroviral therapy?

Viral load Viral load should be measured at baseline and on a regular basis thereafter because viral load is the most important indicator of response to ART. The other tests are not used in this way.

During assessment of a patient with Kaposi's sarcoma, the nurse knows to look for the initial sign of:

Deep purple cutaneous lesions. Localized cutaneous lesions may be the first manifestation of this HIV-related malignancy, which appears in 90% of patients as immune function deteriorates. Other symptoms develop over time as the lesions increase in size and spread to other locations.

The nurse is performing an admission assessment on a patient with AIDS. When assessing the patient's gastrointestinal (GI) system what is most likely to be the priority nursing diagnosis?

Diarrhea Diarrhea is a problem in 50% to 90% of all AIDS patients. In patients with AIDS, the effects of diarrhea can be devastating in terms of profound weight loss, fluid and electrolyte imbalances, perianal skin excoriation, weakness, and the inability to perform self-care activities. Although the patient may experience bowel incontinence related to the diarrhea, the priority GI-related nursing diagnosis for more than 50% of patients with AIDS is diarrhea.

A client is suspected of having an immune system disorder. The physician wants to perform a diagnostic test to confirm the diagnosis. What test might the physician order?

Enzyme-linked immunosorbent assay Explanation: T-cell and B-cell assays (or counts) and the enzyme-linked immunosorbent assay may be performed. A C-cell assay and plasmapherisis are distractors for this question. A complete chemistry panel is not a diagnostic test for an immune system disorder.

Kaposi sarcoma (KS) is diagnosed through

biopsy. KS is diagnosed through biopsy of the suspected lesions. Visual assessment will not confirm a diagnosis. A computed tomography scan will not assist in determining skin cell changes. Skin scraping is a procedure to collect cells, not to evaluate cells.

The lower the client's viral load,

the longer the survival time. The lower the client's viral load, the longer the time to AIDS diagnosis and the longer the survival time. The key goal of antiretrovial therapy is to achieve and maintain durable viral suppression.

A client receiving antiretroviral therapy reports "not urinating enough." What is the nurse's best action?

Assess blood urea nitrogen and creatinine. Adverse effects associated with antiretroviral therapy include potential nephrotoxicity. Assessing blood urean nitrogen and creatinine for clients who have decreased urination is appropriate. The other answers will not assist the nurse in determining the client's problem, which should be assessed before intervention are administered.

When learning about HIV/AIDS, the student should be able to differentiate the two subtypes of virus by which characteristic?

HIV-1 is more prevalent than HIV-2 subtypes Two HIV subtypes have been identified: HIV-1 and HIV-2. HIV-1 mutates easily and frequently, producing multiple substrains that are identified by letters from A through O. HIV-2 is less transmittable, and the interval between initial infection with HIV-2 and development of AIDS is longer. HIV-1 is more prevalent in the United States and in the rest of the world. Western Africa is the primary site of infection with HIV-2. There is no cure for HIV/AIDS; hence, no cure rate. The virus is thought to be a mutation of a simian virus. Transmission of the virus is not a characteristic.

A client with AIDS is experiencing pain secondary to Kaposi's sarcoma. The nurse would most likely expect the client to describe the pain as which of the following?

Sharp, throbbing pressure The pain associated with Kaposi's sarcoma is typically described as sharp, throbbing pressure and heaviness. Pain related to peripheral neuropathy frequently is described as burning, numbness, and "pins and needles." Dull, cramping pain and crushing widespread pressure are not associated with Kaposi's sarcoma.

A nurse is teaching high school students about transmission of the human immunodeficiency virus (HIV). Which comment by a student warrants clarification by the nurse?

"I won't donate blood because I don't want to get AIDS." HIV is transmitted through infected blood, semen, and certain other body fluids. Although a transfusion with infected blood may cause HIV infection in the recipient, a person can't become infected by donating blood. The other options reflect accurate understanding of HIV transmission.

Postexposure prophylaxis (PEP) medications should be started within __________ after exposure, but no longer than __________, to offer any benefit. It must be taken for __________.

1 hour; 72 hours; 4 weeks Prophylaxis needs to start immediately after exposure. After 72 hours, no benefit is offered because of the rapid increases in viral load upon initial infection.

A patient is infected with HIV after sharing needles with another intravenous (IV) drug abuser. Upon infection with HIV, the immune system responds by making antibodies against the virus, usually within how many weeks after infection?

3 to 12 weeks When a person is infected with HIV, the immune system responds by producing antibodies against the virus, usually within 3 to 12 weeks after infection.

A client who is HIV positive is receiving highly active antiretroviral therapy (HAART) that includes a protease inhibitor (PI). The client comes to the clinic for a follow-up visit. Assessment reveals lipoatrophy of the face and arms. The client states, "I'm thinking the side effects of the drug are worse than the disease. Look what's happening to me." The nurse would most likely identify which nursing diagnosis as the priority?

Disturbed body image related to loss of fat in the face and arms The client is experiencing lipoatrophy, which results in a localized loss of subcutaneous fat in the face (manifested as sinking of the cheeks, eyes, and temples), arms, legs, and buttocks. These changes as well as his statement about the side effects of the drug being worse than the disease indicate that he is concerned about how he appears to others. Therefore, the nursing diagnosis of disturbed body image would be the priority. Deficient knowledge, risk for infection, and risk for impaired liver function may be applicable; however, they are not concerns at this time.

Nursing students are reviewing the pathophysiology of human immunodeficiency virus (HIV). They demonstrate understanding of the information when they state which of the following as containing the genetic viral material?

Ribonucleic acid (RNA) HIV is a retrovirus that carries its genetic material in the form of RNA rather than DNA. HIV consists of a viral core containing the viral RNA, surrounded by an envelope consisting of protruding glycoproteins.

A client who is HIV positive is experiencing severe diarrhea. Which laboratory test result would the nurse expect to find?

Hypokalemia Electrolyte imbalances such as decreased sodium, potassium, calcium, magnesium, and chloride typically result from profuse diarrhea. A urine specific gravity of 1.010 would indicate dilute urine. The client with severe diarrhea most likely would be dehydrated, leading to a high urine specific gravity. Proteinuria may suggest renal dysfunction and would not be associated with severe diarrhea unless the client was developing renal failure.

You are caring for a client who has a diagnosis of HIV. Part of this client's teaching plan is educating the client about his or her medications. What is essential for the nurse to include in the teaching of this client regarding medications?

Side effects of drug therapy Describing the side effects of drug therapy is essential, with the admonition to refrain from discontinuing any of the prescribed drugs without first consulting the prescribing physician. Although the client may want to know how the drugs work in general, the specific action of each antiretroviral drug is not essential information. Teaching about condoms and vaccinations may be appropriate, but these topics are not directly related to the client's HIV medications.

A patient in the clinic states, "My boyfriend told me he went to the clinic and was treated for gonorrhea." While testing for the sexually transmitted infection (STI), what else should be done for this patient?

Inform the patient that it would be beneficial to test for HIV. HIV screening is recommended for all persons who seek evaluation and treatment for STIs. HIV testing must be voluntary and free of coercion. Patients must not be tested without their knowledge. HIV screening after notifying the patient that an HIV test will be performed (unless the patient declines) is recommended in all health care settings. Specific signed consent for HIV testing should not be required. In most settings, general informed consent for medical care is considered sufficient.

A protease inhibitor, an antiretroviral agent that can be taken without regard to meals is:

Lexiva. The advantage and appeal of Lexiva is its ability to be taken without food. However, it does have gastrointestinal side effects, and it causes a skin rash in 19% of patients.

Which option should the nurse encourage to replace fluid and electrolyte losses in a client with AIDS?

Liquids The nurse should encourage clients with AIDS to consume liquids in order to help replace fluid and electrolyte losses. Gluten and sucrose may increase the complication of malabsorption. Large doses of iron and zinc should be avoided because they can impair immune function.

The nurse teaches the client that reducing the viral load will have what effect?

Longer survival The lower the client's viral load, the longer the survival time and the longer the time to AIDS diagnosis.

HIV is harbored within which type of cell?

Lymphocyte Because HIV is harbored within lymphocytes, a type of white blood cell, any exposure to infected blood results in significant risk of infection. HIV infection is not harbored in platelets, erythrocytes, or nerve cells.

The nurse administers an injection to a client with AIDS. When finished, the nurse attempts to recap the needle and sustains a needlestick to the finger. What is the priority action by the nurse?

Report the incident to the supervisor. Because post exposure protocols can reduce the risk of HIV infection if initiated promptly, nurses must immediately report any needlestick or sharp injury to a supervisor. Obtaining counseling will occur after all other procedures are adhered to. The lab will draw blood from the client if required for documentation and other blood transmitted disorders.

A client with AIDS is admitted to the hospital with severe diarrhea and dehydration. The physician suspects an infection with Cryptosporidium. What type of specimen should be collected to confirm this diagnosis?

Stool specimen for ova and parasites A stool specimen for ova and parasites will give a definitive diagnosis. The organism is spread by the fecal-oral route from contaminated water, food, or human or animal waste. Those infected can lose from 10 to 20 L of fluid per day. Losing this magnitude of fluid quickly leads to dehydration and electrolyte imbalances.

A client that is HIV+ has been diagnosed with Pneumocystis pneumonia caused by P. jiroveci. What medication does the nurse expect that the client will take for the treatment of this infection?

Trimethoprim-sulfamethoxazole To prevent and treat Pneumocystis pneumonia, trimethoprim-sulfamethoxazole (Bactrim, Septra) is prescribed. The other medications are antifungals and used to treat candidiasis.

A nurse is implementing appropriate infection control precautions for a client who is positive for human immunodeficiency virus (HIV). The nurse demonstrates a need for a review of transmission routes by identifying which body fluid as a means of transmission?

Urine HIV is transmitted in body fluids that contain free virions and infected CD4+ T cells. These fluids include blood, seminal fluid, vaginal secretions, amniotic fluid, and breast milk. Urine is not a body fluid responsible for HIV transmission.

A client is to have a hip replacement in 3 months and does not want a blood transfusion from random donors. What option can the nurse discuss with the client?

Bank autologous blood. Signing the refusal form does not give the client any information about the options that are available and place the client at risk. Banking autologous blood that is self-donated is the safest option for the client. Directed donor blood may be no safer than blood collected from public donors. Those who support this belief say that directed donors may not reveal their high-risk behaviors that put the potential recipient at risk for blood-borne pathogens such as HIV.

A hospital educator is reiterating the importance of Standard Precautions to a group of nursing students who will soon begin a clinical rotation on the unit. Which of the following statements best describes the application of Standard Precautions?

Standard Precautions should be applied to patients regardless of diagnosis or presumed infectious status. Standard Precautions incorporate the major features of Universal Precautions (designed to reduce the risk of transmission of bloodborne pathogens) and Body Substance Isolation (designed to reduce the risk of transmission of pathogens from moist body substances); they are applied to all patients in health care facilities regardless of their diagnosis or presumed infectious status.

An older adult widowed woman informs the nurse that she notices vaginal dryness now that she has become sexually active again. She is not using barrier protection because it makes the dryness worse. What education should the nurse provide to the patient?

Vaginal dryness is common in postmenopausal women, and there are creams that can be used, but she should use a latex condom. Other than abstinence, consistent and correct use of condoms (Chart 37-3) is the only effective method to decrease the risk of sexual transmission of HIV infection. When latex male condoms are used consistently and correctly during vaginal or anal intercourse, they are highly effective in preventing the sexual transmission of HIV (CDC, 2011d). Nonlatex condoms made of natural materials such as lambskin are available for people with latex allergy but will not protect against HIV infection.

The nurse practitioner reviews laboratory results requested to track HIV. Which of the following is a laboratory test that measures HIV RNA levels and is the best predictor of HIV disease progression?

Viral load The viral load test quantifies the plasma HIV RNA levels and response to treatment of the HIV infection. It also confirms a positive EIA result and detects HIV in high-risk seronegative individuals before antibodies are measurable.

Which assessment finding(s) are likely to cause noncompliance with antiretroviral treatment? Select all that apply.

Active substance abuse Psychosocial barriers such as depression and other mental illnesses, neurocognitive impairment, low health literacy, low levels of social support, stressful life events, high levels of alcohol consumption and active substance use, homelessness, poverty, nondisclosure of HIV serostatus, denial, stigma, and inconsistent access to medications affect adherence to ART. Past substance abuse has not been implicated as a factor for noncompliance with antiretroviral treatment.

A client suspected of having HIV has blood drawn for a screening test. What is the first test generally run to see if a client is, indeed, HIV positive?

ELISA The enzyme-linked immunosorbent assay (ELISA) test, an initial HIV screening test, is positive when there are sufficient HIV antibodies; it also is positive when there are antibodies from other infectious diseases. If the ELISA is positive twice then the Western Blot test is run. A CBC and a Schick test are not screening tests for HIV.

A client is administered foscarnet to treat a case of CMV retinitis. Which adverse effect should the nurse closely monitor in the client?

Electrolyte imbalances Alterations in renal function, fever, nausea, electrolyte imbalances, and diarrhea are the most common adverse effects of foscarnet and should be closely monitored. The drug does not cause hypotension. On the other hand, peripheral neuropathy is an adverse effect of administering drugs such as didanosine and zalcitabine. Anemia is an adverse effect of administering zidovudine.

Which of the following is the first barrier method that can be controlled by the woman?

Female condom The female condom has the distinction of being the first barrier method that can be controlled by the woman. The IUD may increase the risk for HIV transmission through an inflammatory foreign body response. The female condom is as effective in preventing pregnancy as other barrier methods, such as the diaphragm and the male condom. Birth control pills are not a barrier method.

A client with AIDS is brought to the clinic by their family. The family tells the nurse the client has become forgetful, with a limited attention span, decreased ability to concentrate, and delusional thinking. What condition is represented by these symptoms?

HIV encephalopathy HIV encephalopathy, also called AIDS dementia complex or ADC, is a neurologic condition that causes the degeneration of the brain, especially in areas that affect mood, cognition, and motor functions. Such clients exhibit forgetfulness, limited attention span, decreased ability to concentrate, and delusional thinking. DSP is characterized by abnormal sensations, such as burning and numbness in the feet and later in the hands. Candidiasis is a yeast infection that may develop in the oral, pharyngeal, esophageal, or vaginal cavities or in the folds of the skin. CMV infects the choroid and retinal layers of the eye, leading to blindness, and can also cause ulcers in the esophagus, colitis, diarrhea, pneumonia, and encephalitis.

When preparing a client with acquired immunodeficiency syndrome (AIDS) for discharge to home, the nurse should be sure to include which instruction?

"Avoid sharing such articles as toothbrushes and razors." The human immunodeficiency virus (HIV), which causes AIDS, is most concentrated in the blood. For this reason, the client shouldn't share personal articles that may be blood-contaminated, such as toothbrushes and razors, with other family members. HIV isn't transmitted by bathing or by eating from plates, utensils, or serving dishes used by a person with AIDS.

The nurse is discussing sexual activity with a patient recently diagnosed with HIV. The patient states, "As long as I have sex with another person who is already infected, I will be okay." What is the best response by the nurse?

"You should avoid having unprotected sex with a person who is HIV positive because you can increase the severity of the infection in both you and your partner." Patients, families, and friends are educated about the routes of transmission of HIV. The nurse discusses precautions the patient can use to avoid transmitting HIV sexually or through sharing of body fluids, especially blood.

The nurse is talking with a group of teens about transmission of human immunodeficiency virus (HIV). What body fluids does the nurse inform them will transmit the virus? Select all that apply.

- semen - breast milk - blood - vaginal secretions There are only four known body fluids through which HIV is transmitted: blood, semen, vaginal secretions, and breast milk. HIV may be present in saliva, tears, and conjunctival secretions, but transmission of HIV through these fluids has not been implicated. HIV is not found in urine, stool, vomit, or sweat.

The nursing instructor is talking about HIV/AIDS with their pre-nursing pathophysiology class. The instructor explains to the class that the virus that causes HIV/AIDS is called a retrovirus. What characteristics of this retrovirus would the instructor talk with the class about?

HIV-1 and HIV-2 subtypes Two HIV subtypes have been identified: HIV-1 and HIV-2. HIV-1 mutates easily and frequently, producing multiple substrains that are identified by letters from A through O. HIV-2 is less transmittable, and the interval between initial infection with HIV-2 and development of AIDS is longer. HIV-1 is more prevalent in the United States and in the rest of the world. Western Africa is the primary site of infection with HIV-2. There is no cure for HIV/AIDS hence, no cure rate. The virus is thought to be a mutation of a simian virus. Transmission of the virus is not a characteristic.

A client with AIDS is exhibiting shortness of breath, cough, and fever. The nurse most likely would suspect infection with which of the following?

Pneumocystis jiroveci Although mycobacterium, legionella, and cytomegalovirus may cause the signs and symptoms described, the most common infection in people with AIDS is pneumocystitis pneumonia caused by pneumocystis jiroveci. It is the most common opportunistic infection associated with AIDS.

A client is beginning highly active antiretroviral therapy (HAART). The client demonstrates an understanding of the need for follow up when he schedules a return visit for viral load testing at which time?

6 weeks Viral load tests are measured immediately before initiating antiretroviral therapy and then again in 2 to 8 weeks. In most clients, adherence to a regimen of potent antiretroviral agents should result in a large decrease in the viral load by 2 to 8 weeks. Therefore, a return visit at 6 weeks would be in this time frame. By 16 to 20 weeks, the viral load should continue to decline, dropping below detectable levels.

A healthcare worker has been exposed to the blood of an HIV-positive client and is awaiting the results of an HIV test. In the meantime, what precautions must the healthcare worker take to prevent the spread of infection?

Follow the same sexual precautions as someone who has been diagnosed with AIDS. The healthcare worker will be tested for HIV at regular intervals and treated with antiretrovirals depending on the results of the tests or the potential for infection. While awaiting the results, the healthcare worker should follow the same sexual precautions as someone who has been diagnosed with AIDS. The healthcare worker should not limit interactions with either non-HIV-infected or HIV-infected people. In addition, the healthcare worker should not quit and be admitted to a hospital for treatment. Treatment, if required, can begin if the result of the test is positive.

Which of the following indicates that a client with HIV has developed AIDS?

Herpes simplex ulcer persisting for 2 months A diagnosis of AIDS cannot be made until the person with HIV meets case criteria established by the Centers for Disease Control and Prevention. The immune system becomes compromised. The CD4 T-cell count drops below 200 cells and develops one of the opportunistic diseases, such as Pneumocystis carinii pneumonia, candidiasis, cytomegalovirus, or herpes simplex.

A patient had unprotected sex with an HIV-infected person and arrives in the clinic requesting HIV testing. Results determine a negative HIV antibody test and an increased viral load. What stage does the nurse determine the patient is in?

Primary infection The period from infection with HIV to the development of HIV-specific antibodies is known as primary infection, or stage 1. Initially, there is a period during which those who are HIV positive test negative on the HIV antibody blood test, although they are infected and highly infectious, because their viral loads are very high.

A client has been diagnosed with HIV and has been placed on antiretroviral therapy. What does the nurse inform the client will be required for determining the progression of the disease as well as guiding drug therapy?

Viral load and T4-cell counts will be performed every 2 to 3 months. Viral load testing is used to guide drug therapy and follow the progression of the disease. Viral load tests and T4-cell counts may be performed every 2 to 3 months once it is determined that a person is HIV positive. The medication should be adhered to and not discontinued. There is no cure for the disease at this time. Antiretroviral therapy is not generally changed or added to without reason or lack of response. The Western blot is used for confirmation of the presence of the HIV virus.

A client with suspected HIV has had two positive enzyme-linked immunosorbent assay tests. What diagnostic test would be run next?

Western Blot The enzyme-linked immunosorbent assay (ELISA) test, an initial HIV screening test, is positive when there are sufficient HIV antibodies; it also is positive when there are antibodies from other infectious diseases. The test is repeated if results are positive. If results of a second ELISA test are positive, the Western blot is performed. A positive result on Western blot confirms the diagnosis; however, false-positive and false-negative results on both tests are possible. A polymerase chain reaction gives the viral load of the client. The T4/T8 ratio determines the status of T lymphocytes.

The term used to define the amount of virus in the body after the initial immune response subsides is

viral set point. The amount of virus in the body after the initial immune response subsides is referred to as the viral set point, which results in an equilibrium between HIV levels and the immune response that may be elicited. During the primary infection period, the window period occurs because a person is infected with HIV but negative on the HIV antibody blood test. The period from infection with HIV to the development of antibodies to HIV is known as the primary infection stage. The amount of virus in circulation and the number of infected cells equals the rate of viral clearance.

A nurse works in an employee health department of a hospital. She was asked to treat a staff nurse who was exposed to blood from a patient with an HIV infection. The nurse practitioner instituted a PEP protocol that includes which of the following actions? Select all that apply.

- Continue HIV medications for 4 weeks postexposure. - Initiate postexposure testing after 4 weeks. - Finish postexposure testing at 6 months. Refer to Box 37-4 in the text

A client is prescribed didanosine (Videx) as part of his highly active antiretroviral therapy (HAART). Which instruction would the nurse emphasize with this client?

"Be sure to take this drug about 1/2 hour before or 2 hours after you eat." Didanosine should be taken 30 to 60 minutes before or 2 hours after meals. Other antiretroviral agents, such as abacavir, emtricitabine, or lamivudine can be taken without regard to meals. High-fat meals should be avoided when taking amprenavir. Atazanavir should be taken with food and not with antacids.

A patient develops gastrointestinal bleeding from a gastric ulcer and requires blood transfusions. The patient states to the nurse, "I am not going to have a transfusion because I don't want to get AIDS." What is the best response by the nurse?

"I understand your concern. The blood is screened very carefully for different viruses as well as HIV." Blood and blood products can transmit HIV to recipients. However, the risk associated with transfusions has been virtually eliminated as a result of voluntary self-deferral, completion of a detailed health history, extensive testing, heat treatment of clotting factor concentrates, and more effective virus inactivation methods. Donated blood is tested for antibodies to HIV-1, human immunodeficiency virus type 2 (HIV-2), and p24 antigen; in addition, since 1999, nucleic acid amplification testing (NAT) has been performed.

The nurse is instructing a male client about safer sexual behaviors. Which client statement indicates a need for additional instruction?

"I will apply baby oil to lubricate the condom." The client should use only water-soluble lubricant, such as K-Y jelly or glycerin. Baby oil can cause the condom to break. The client should use a new condom for each sexual activity and hold onto the condom so that it does not come off when pulling out. Manual-anal intercourse should be avoided.

The nurse receives a phone call at the clinic from the family of a patient with AIDS. They state that the patient started "acting funny" after complaining of headache, tiredness, and a stiff neck. Checking the temperature resulted in a fever of 103.2°F. What should the nurse inform the family member?

"The patient may have cryptococcal meningitis and will need to be evaluated by the physician." A fungal infection, Cryptococcus neoformans is another common opportunistic infection among patients with AIDS, and it causes neurologic disease. Cryptococcal meningitis is characterized by symptoms such as fever, headache, malaise, stiff neck, nausea, vomiting, mental status changes, and seizures.

A patient with HIV has been on antiretroviral therapy (ART) for 6 months. The patient comes to the clinic with home medications and the nurse observes that there are too many pills in the container. What does the nurse know about the factors associated with nonadherence to ART? (Select all that apply.)

- Active substance abuse - Depression - Lack of social support Factors associated with nonadherence include active substance abuse, depression, and lack of social support.

Which of the following are modes of transmission for HIV? Select all that apply.

- Blood - Seminal fluid - Vaginal secretions - Amniotic fluid HIV-1 is transmitted in body fluids containing HIV CD4+ T lymphocytes. These fluids include blood, seminal fluid, vaginal secretions, amniotic fluid, and breast milk. HIV is not transmitted by casual contact.

Which characteristics have been implicated as factors for noncompliance with antiretroviral treatment?

Active substance abuse Factors associated with nonadherence include active substance abuse, depression, and lack of social support, as well as neurocognitive impairment, low health literacy, stressful life events, high levels of alcohol consumption, homelessness, poverty, nondisclosure of HIV serostatus, denial, stigma, and inconsistent access to medications. Past substance abuse has not been implicated as a factor for noncompliance with antiretroviral treatment.

What intervention is a priority when treating a client with HIV/AIDS?

Assessing fluid and electrolyte balance Fluid and electrolyte deficits are a priority in monitoring clients with HIV/AIDS, and assessment of fluid loss and electrolyte imbalance is essential. Skin integrity should be monitored but is a lower priority. Neurologic and psychological status should also be monitored, but this is not as high a priority as fluid and electrolyte imbalance.

The nurse identifies a nursing diagnosis of ineffective airway clearance related to pneumocystis pneumonia and increased bronchial secretions for a client with AIDS. Which of the following would be appropriate for the nurse to include in the client's plan of care?

Assist with chest physiotherapy every 2 to 4 hours. The nurse should include interventions such as assisting with and/or performing chest physiotherapy every 2 to 4 hours to prevent stasis of secretions, assist the client to attain the semi- or high Fowler's position to facilitate breathing and airway clearance, allow for frequent rest periods to prevent excessive fatigue, and maintain a fluid intake of at least 3 liters per day unless contraindicated.

A nurse is preparing an in-service presentation about human immunodeficiency virus (HIV) for a group of new graduate nurses. As part of the presentation, the nurse is planning to describe the events that occur once HIV enters the host cell. Which of the following would the nurse describe as the first step?

Attachment Once HIV enters the host cell, attachment occurs in which the glycoproteins of HIV bind with the host's uninfected CD4+ receptor and chemokine coreceptors. This is followed by uncoating, in which HIV's viral core is emptied into the CD4+ T cell. Cleavage and budding occur as the last steps.

A client has discussed therapy for his HIV-positive status. What does the nurse understand is the goal of antiretroviral therapy?

Bring the viral load to a virtually undetectable level The goal of antiretroviral therapy is to bring the viral load to a virtually undetectable level. This level is no more than 500 or 50 copies, depending on the sensitivity of the selected viral load test. It is not possible to reverse the status to a negative, and it cannot eliminate the risk of AIDS but can help with prolonging the asymptomatic stage of HIV. Antiretroviral therapy does not treat mycobacterium avium complex.

Which is usually the most important consideration in the decision to initiate antiretroviral therapy?

CD4+ counts The most important consideration in decisions to initiate antiretroviral therapy is CD4+ counts.

A client with AIDS comes to the clinic reporting difficulty swallowing. He says, "It hurts so much when I swallow." Inspection reveals creamy white patches in the client's mouth. Which of the following would the nurse suspect?

Candidiasis The client's complaints and physical examination suggest oral candidiasis. Wasting syndrome involves involuntary weight loss greater than 10% of the client's baseline body weight and either chronic diarrhea for more than 10 days or chronic weakness and documented intermittent or constant fever in the absence of any concurrent illness that could explain these findings. Cryptococcus neoformans is a fungal infection that affects the neurologic system. Clostridium difficile is a common cause of chronic diarrhea in clients with AIDS.

The nurse practitioner who is monitoring the patient's progression of HIV is aware that the most debilitating gastrointestinal condition found in up to 90% of all AIDS patients is:

Chronic diarrhea. Chronic diarrhea is believed related to the direct effect of HIV on cells lining the intestine. Although all gastrointestinal manifestations of AIDS can be debilitating, the most devastating is chronic diarrhea. It can cause profound weight loss and severe fluid and electrolyte imbalances.

Other than abstinence, what is the only proven method of decreasing the risk of sexual transmission of HIV infection?

Consistent and correct use of condoms Other than abstinence, consistent and correct use of condoms is the only method proven to decrease the risk for sexual transmission of HIV infection. Vaginal lubricants, birth control pills, and spermicides are not proven means of decreasing the risk for sexual transmission of HIV infection.

There are many ethical issues in the care of clients with HIV or HIV/AIDS. What is an ethical issue healthcare providers deal with when caring for clients with HIV/AIDS?

Disclosure of the client's condition Despite HIV-specific confidentiality laws, clients infected with AIDS fear that disclosure of their condition will affect employment, health insurance coverage, and even housing. Since healthcare providers do not share a client's diagnosis with a support group, option A is incorrect. Caring for a client with an infectious terminal illness that can be transmitted to other people is a concern for healthcare providers but it is not an ethical issue.

Which blood test confirms the presence of antibodies to HIV?

Enzyme-linked immunosorbent assay (ELISA) ELISA and Western blotting identify and confirm the presence of antibodies to HIV. ESR is an indicator of the presence of inflammation in the body. The p24 antigen test is a blood test that measures viral core protein. Reverse transcriptase is not a blood test. Rather, it is an enzyme that transforms single-stranded RNA into double-stranded DNA.

A client is admitted with a tentative diagnosis of acquired immunodeficiency syndrome (AIDS). He undergoes biopsies of facial lesions. The preliminary report indicates Kaposi's sarcoma. Which action by the nurse is most appropriate?

Explore the client's feelings about his facial disfigurement. The nurse should help the client explore his feelings about his facial disfigurement because facial lesions can contribute to decreased self-esteem and an altered body image. Discussing AIDS with a client whose diagnosis isn't final may be inappropriate and doesn't provide emotional support. Pretending not to notice visible lesions ignores the client's concerns. The physician, not the nurse, should inform the client of the biopsy results.

A nurse is working in a support group for clients with acquired immunodeficiency syndrome (AIDS). Which point is most important for the nurse to stress?

Following safer-sex practices It's essential for clients with AIDS to follow safer-sex practices to prevent transmission of the human immunodeficiency virus. Although it's helpful if clients with AIDS avoid using recreational drugs and alcohol, it's more important that I.V. drug users use clean needles and dispose of used needles for purposes of avoiding transmission. Whether the client with AIDS chooses to tell anyone about the diagnosis is his decision; there is no legal obligation to do so.

The nurse is reviewing the medical record of a client who is positive for human immunodeficiency virus (HIV). The nurse notes that the client is classified as HIV asymptomatic based on which CD4+ T lymphocyte count?

Greater than 500/mm3 A client is classified as HIV asymptomatic when the CD4+ T lymphocyte count is greater than 500/mm3. A person is considered HIV symptomatic when the CD4+ count is 200 to 499/mm3. A person is considered to have aquired immunodeficiency syndrome (AIDS) when the CD4+ count is less than 200/mm3.

A woman infected with HIV comes into the clinic. What symptoms may be the focus of a medical complaint in women infected with HIV?

Gynecologic problems In women with HIV, gynecologic problems, such as abnormal results of Papanicolaou tests, genital warts, pelvic inflammatory disease, and persistent vaginitis may be the focus of a majority of complaints. Acute retroviral syndrome (viremia) may be the chief complaint in one third to more than one half of those infected, not necessarily women. Its manifestations include rashes, muscle and joint pain, and weight loss.

Which of the following is the most common HIV-related malignancy?

Kaposi's sarcoma Kaposi's sarcoma is the most common HIV-related malignancy and involves the endothelial layer of blood and lymphatic vessels. Kaposi's sarcoma, certain types of B-cell lymphomas, and invasive cervical carcinoma are included in the CDC classification of AIDS-related malignancies.

The nurse advises a patient who has received a negative test result from his HIV antibody test that he:

May be infected but antibodies are not currently present. A negative test result indicates that antibodies to HIV are not present in the blood at the time of the testing. This means either the patient has not been infected or, if infected, that the body has not yet produced antibodies. Refer to Box 37-5 in the text.

A client comes in to get an EIA test done because the physician suspects AIDS. Which nursing action is essential before an EIA test is performed?

Obtaining a general consent for medical care from the client Separate written consent for HIV testing should not be required; general consent for medical care should be considered sufficient to encompass consent for HIV testing. Western blotting is performed if the results of the EIA test are positive. A polymerase chain reaction test, which measures viral loads, is used if diagnosis is confirmed as positive.

The nurse completes a history and physical assessment on a patient with AIDS who was admitted to the hospital with respiratory complications. The nurse knows to assess for the most common infection in persons with AIDS (80% occurrence). This is:

Pneumocystis pneumonia. Pneumocystic pneumonia (PCP) is one of the first and most common opportunistic infections associated with AIDS. It may be present despite the absence of crackles. If untreated, PCP progresses to cause significant pulmonary impairment and respiratory failure.

Which stage of HIV infection is indicated when the results are more than 500 CD4+ lymphocytes/mm?

Primary infection A result between 500 and 1500 CD4+ T lymphocytes/mm3 indicates CDC stage 1.

The period from infection with HIV to the development of antibodies to HIV is known as which of the following?

Primary infection Primary infection is the period from the infection with HIV to the development of antibodies to HIV. The viral load test measures plasma HIV RNA levels. Viral set point is the balance between the amount of HIV in the body and the immune response. Anergy is the absence of an immune response.

A client taking abacavir has developed fever and rash. What is the priority nursing action?

Report to the health care provider. Fever and a rash could be indicative of a hypersensitivity reaction. Hypersensitivity reactions are also known as anaphylactic reactions and often involve skin rashes, fever, and bronchopulmonary issues such as bronchial constriction. The health care provider should be notified immediately and the medication stopped. Interventions need to be taken to assure that the client's airway is not compromised. Administering acetaminophen and documentation and treating the rash are not the priority and would be completed after the client is stabilized.

A client with HIV will be started on a medication regimen of three medications. What drug will the nurse instruct the client about?

Reverse transcriptase inhibitors Reverse transcriptase inhibitors are drugs that interfere with the virus' ability to make a genetic blueprint. A protease inhibitor is a drug that inhibits the ability of virus particles to leave the host cell. The integrase inhibitors are a class of drug that prevents the incorporation of viral DNA into the host cell's DNA. Hydroxyurea is a drug that is used as an adjunct therapy that tries to halt the progression of AIDS.

A client in a late stage of acquired immunodeficiency syndrome (AIDS) shows signs of AIDS-related dementia. Which nursing diagnosis takes highest priority?

Risk for injury In a client with AIDS, central nervous system (CNS) deterioration can lead to AIDS-related dementia. This type of dementia impairs cognition and judgment, placing the client at risk for injury. Although Bathing or hygiene self-care deficit and Complicated grieving may be relevant in AIDS, these diagnoses don't take precedence in a client with AIDS-related dementia. Because CNS deterioration results from infection, Ineffective cerebral tissue perfusion isn't applicable.

A new nursing graduate is working at the hospital in the medical-surgical unit. The preceptor observes the nurse emptying a patient's wound drain without gloves on. What important information should the preceptor share with the new graduate about standard precautions?

Standard precautions should be used with all patients to reduce the risk of transmission of bloodborne pathogens. Standard precautions are designed to reduce the risk of transmission of bloodborne pathogens and of pathogens from moist body substances. Standard precautions are used when working with all patients in all health care settings, regardless of their diagnosis or presumed infectious status (Siegel, Rhinehart, Jackson, et al., 2007).

A client taking fosamprenavir reports "getting fat." What is the nurse's best action?

Teach the client about medication side effects. The client needs to be aware of the potential for fat redistribution. Exercise, diet, and counseling will not change the outcome of this side effect.

The nurse is gathering data from laboratory studies for a client who has HIV. The clients T4-cell count is 200/mm3, and the client has been diagnosed with Pneumocystis pneumonia. What does this indicate to the nurse?

The client has converted from HIV infection to AIDS. AIDS is the end stage of HIV infection. Certain events establish the conversion of HIV infection to AIDS: a markedly decreased T4 cell count from a normal level of 800 to 200/mm3 and the development of certain cancers and opportunistic infections. The client does not have advanced HIV; they meet the criteria for the development of AIDS. The T4-cell count is not decreasing due to an infection.

A client on antiretroviral drug therapy is discussing with the nurse that sometimes he "forgets to take his meds for a few days." What should the nurse inform the client can occur when the medications are not taken as prescribed?

The client is risking the development of drug resistance and drug failure. Clients who neglect to take antiretroviral drugs as prescribed risk development of drug resistance. When drug levels are not adequately maintained, viral replication and mutations increase. Noncompliant clients are one cause of antiretroviral drug therapy. Funding will not cease for noncompliance. The medications are not all available in IV form.

A 16-year-old client suspected of having HIV/AIDS asks the nurse what causes AIDS. What should the nurse say?

The human immunodeficiency virus A pathogen known as the human immunodeficiency virus (HIV) causes AIDS. HIV/AIDS is not caused by either the streptococcal or the staphylococcal bacteria; it is also not caused by the Epstein-Barr virus.

Which term defines the balance between the amount of HIV in the body and the immune response?

Viral set point The viral set point is the amount of virus in the body after the initial immune response subsides is referred to as the viral set point, which results in an equilibrium between HIV levels and the immune response that may be elicited. During the primary infection period, the window period occurs because a person is infected with HIV but negative on the HIV antibody blood test. The period from infection with HIV to the development of antibodies to HIV is known as the primary infection stage. The amount of virus in circulation and the number of infected cells equals the rate of viral clearance.

A client has undergone diagnostic testing for human immunodeficiency virus (HIV) using the enzyme immunoassay (EIA) test. The results are positive and the nurse prepares the client for additional testing to confirm seropositivity. The nurse would prepare the client for which test?

Western blot assay A positive EIA test indicates seropositivity. To confirm this, a Western blot assay would be done. The OraSure test uses saliva to perform an EIA test. The p24 antigen test and nucleic acid sequence-based amplification test are used to test viral load and evaluate response to treatment. However, the reverse transcriptase-polymerase chain reaction (RT-PCR) and nucleic acid sequence-based tests have replaced the p24 antigen test. The RT-PCR tests may be used to confirm a positive EIA result.

A client with suspected exposure to HIV has been tested with the enzyme-linked immunosorbent assay (ELISA) with positive results twice. The next step for the nurse to explain to the client for confirmation of the diagnosis is to perform a:

Western blot test for confirmation of diagnosis. The enzyme-linked immunosorbent assay (ELISA) test, an initial HIV screening test, is positive when there are sufficient HIV antibodies; it also is positive when there are antibodies from other infectious diseases. The test is repeated if results are positive. If results of a second ELISA test are positive, the Western blot is performed. The p24 antigen test and the polymerase chain reaction test determine the viral load, and the T4-cell count is not used for diagnostic confirmation of the presence of HIV in the blood.

A nurse is collecting objective data for a client with AIDS. The nurse observes white plaques in the client's oral cavity, on the tongue, and buccal mucosa. What does this finding indicate?

candidiasis Candidiasis is a yeast infection caused by the Candida albicans microorganisms. It may develop in the oral, pharyngeal, esophageal, or vaginal cavities or in folds of the skin. It is often called thrush when located in the mouth. Inspection of the mouth, throat, or vagina reveals areas of white plaque that may bleed when mobilized with a cotton-tipped swab. Kaposi's sarcoma is a purple lesion and is an opportunistic cancer. Hairy leukoplakia is also an indication of oral cancer. Coccidiomycosis causes diarrhea in the immunosuppressed client.

A client with cytomegalovirus (CMV) infection reports difficulty seeing. The physician determines that the client is developing CMV retinitis. What medication does the nurse anticipate the client will receive for this?

foscarnet The drug foscarnet is used to treat CMV retinitis and is given by controlled IV infusion. Alterations in renal function, fever, nausea, anemia, numbness in the extremities, and diarrhea are the most common adverse effects. Zidovudine is used in antiretroviral therapy to prevent the conversion of HIV to AIDS. Azithromycin is an antibiotic and not used to treat CMV retinitis.

A female client comes to the clinic and tells the nurse, "I think I have another vaginal infection and I also have some wartlike lesions on my vagina. This is happening quite often." What should the nurse consult with the physician regarding?

testing the client for the presence of HIV Abnormal results of Papanicolaou tests, genital warts, pelvic inflammatory disease, and persistent vaginitis may correlate with HIV infection. Wearing cotton underwear can help with the prevention of candidiasis but does not address the recurrent vaginal infection that may not be caused by a fungus. Abstaining from sexual intercourse does not address the recurrent vaginal infection. A medicated douche can alter the normal flora of the vaginal wall.

The balance between the amount of HIV in the body and the immune response is the

viral set point. The amount of virus in the body after the initial immune response subsides is referred to as the viral set point, which results in an equilibrium between HIV levels and the immune response that may be elicited. A viral load test measures the quantity of HIV RNA in the blood. The window period is the time from infection with HIV until seroconversion detected on HIV antibody test. Anergy is the loss or weakening of the body's immunity to an irritating agent or antigen.