AIDS Infections and Malignancies
Human immunodeficiency virus (HIV) infection is an acquired infection that causes severe immune dysfunction. HIV infection causes the person to be unusually susceptible to other life-threatening infections and malignancies. HIV is caused by a retrovirus that in its most serious form, results in acquired immunodeficiency syndrome (AIDS).
HIV integrates itself into CD4 cells, eventually causing cell death. Since CD4 cells play major roles in regulating immune function, their destruction results in serious impairment of the immune system.
HIV infection manifests in 3 stages: primary HIV infection, chronic asymptomatic disease, and AIDS.
The primary (acute) phase is characterized by symptoms similar to the flu or mononucleosis, such as fever, sore throat, fatigue, nausea/vomiting, headache, rash, or lymphadenopathy. These symptoms generally occur within 2-4 weeks after HIV exposure and last 2-10 weeks. During this time, the virus is replicating rapidly, and there is a corresponding rapid rise in serum HIV RNA copies, a decrease in CD4 cell numbers (as the CD4 cells are being destroyed by the HIV), and a large increase in HIV-specific CD8 cell numbers.
Following the primary phase, there may be a period of latency lasting several months to 10 or more years. The patient may be completely asymptomatic or only have mild symptoms; however, HIV replication continues and they remain infectious. Eventually, the immune system is largely damaged and the rate of viral reproduction increases.
As viral reproduction continues and more CD4 cells are destroyed, the immune system is further compromised. When the viral load and immunodeficiency reach significant levels, serious opportunistic infections occur, and the illness is termed AIDS. AIDS is the end stage of HIV infection and without treatment, death will occur in 3 to 5 years.
Opportunistic infections are pathogens that take the opportunity to produce disease when the immune system is weak. Most symptoms associated with AIDS are from opportunistic infections and can affect every organ and body system. Pulmonary infection is usually the first symptom of AIDS and is a constant threat. Other signs and symptoms are many, including chills and fever, malaise, fatigue and lethargy, night sweats, dry or productive cough, dyspnea, confusion, headache, enlarged lymph nodes, stiff neck, progressing edema, seizures, skin rash, and oral lesions.
Numerous GI problems are associated with opportunistic infections and antiretroviral therapy, including difficulty eating or swallowing, abdominal discomfort, diarrhea, and weight loss – which commonly leads to loss of lean muscle mass.
Many opportunistic infections affect the CNS, including encephalitis, meningitis, and peripheral neuropathy, possibly causing loss of cognitive and motor function.
The eyes are vulnerable to CMV (cytomegalovirus), resulting in blurred vision, decreased acuity, and eventually total blindness unless early and aggressive treatment is started.
Effects on the hematologic system are seen as thrombocytopenia (deficiency of platelets), anemia (deficiency of RBCs), and neutropenia (deficiency of neutrophils, a type of WBC).
Opportunistic infections can also affect the heart by producing myocarditis (inflammation of the heart muscle) or pericarditis (inflammation of the pericardium).
Though not as common, endocrine glands can also be infiltrated with HIV, with the adrenal gland most commonly affected.
Musculoskeletal symptoms are common and may be mild or severe. Joint pain is often seen with acute infection or may result from drug therapy. Muscle pain or weakness may result from decreased appetite and loss of muscle mass.
Fluid, electrolyte, and acid-base imbalances occur from a variety of causes, including acute kidney failure and kidney disease or damage.
AIDS related infections are called opportunistic because the organisms causing infection are not ordinarily pathogenic to a healthy immune system. Opportunistic infections can be caused by viruses, bacteria, fungus, and even parasites. Patients with HIV or AIDS have severely compromised immune systems, so these organisms thrive, multiply, and produce disease. As CD4 cell counts fall below 400 cells per cubic mm, signs and symptoms of immunodeficiency occur; and when CD4 counts fall below 200/cubic mm, more than one opportunistic infection is experienced.
Let’s take a look at some bacterial infections common to AIDS.
Occurring in up to 50% of AIDS patients, Mycobacterium avium complex (MAC) is the most commonly seen bacterial infection, with high concentrations of organisms in the environment—including water, food, soil, and animals. Symptoms of MAC include high fever, night sweats, loss of appetite, diarrhea, weight loss, weakness, and fatigue.
Mycobacterium tuberculosis is another common bacterial infection. This respiratory disease spreads easily in closed-in places, such as shelters and jails. Symptoms include fever, coughing, night sweats, loss of appetite, weight loss, and fatigue. A multidrug regimen of TB medications is given to patients with HIV and active TB.
Other common bacterial infections include recurrent bacterial pneumonia and salmonella.
Fungal infections are a common problem with AIDS patients. The most common fungal diseases include the following:
Pneumocystis pneumonia (PCP) is the most common severe opportunistic infection among AIDS patients and is caused by the fungus Pneumocystis jirovecii. PCP is classified as a fungal pneumonia but does not respond to antifungal treatment. Antibiotics are primarily recommended, with corticosteroids also used in severe cases. It is generally confined to the lungs, but without treatment, it leads to respiratory insufficiency and death.
Candidiasis (thrush), which is a yeast infection usually found in the mouth, GI tract, vagina, and skin.
Cryptococcosis is a fungal infection that usually manifests as meningitis. The organism is found in pigeon droppings, remains viable for 2 years, and can be contracted from nesting places, soil, fruit, and fruit juices. Cryptococcosis primarily affects the central nervous system and lungs, but can also affect the skin, mouth, bones, liver, and kidneys. Pulmonary infection is usually asymptomatic but may cause dyspnea, cough, or chest discomfort. CNS findings include fever, headache, dizziness, blurred vision, memory changes, irritability, N/V, fatigue, convulsions, and death if not treated in a timely manner.
Histoplasmosis is a lung infection caused by fungal spores found in soil and in droppings of bats and birds. It may manifest as an acute pulmonary infection, but more often as disseminated disease, which is most often fatal if not treated aggressively with antifungal therapy. Patients with histoplasmosis and CD4 counts below 200 cells/cubic mm, should avoid activities that increase risk for infection, such as cleaning chicken coops, cleaning or remodeling old buildings, or exploring caves.
Protozoal infections are caused by a variety of organisms, many of which are parasitic.
Cryptosporidium is a parasite commonly encountered in patients with AIDS. It is found in a variety of animal species and is transmitted animal to human, as well as person-to-person, and waterborne transmission. Cryptosporidium is extremely pathogenic to immunocompromised patients. It affects the entire GI tract, causing fever, N/V, abdominal pain and cramping, and severe watery diarrhea. Death can occur from electrolyte imbalances, malnutrition, and dehydration. There are no specific drug regimens to treat cryptosporidium, interventions include nutrition and fluid replacement with antidiarrheal medications.
Toxoplasma gondii is a protozoan that is transmitted in humans through ingestion of meats or vegetables containing oocysts. Animals can also be infected, but cats are the definitive hosts. Toxoplasma infection does not usually cause significant illness in a healthy person, but in an immunocompromised AIDS patient, it is a major cause of encephalitis. The infection may be localized with mild symptoms similar to those of mononucleosis, or it may be disseminated, which is serious and includes symptoms such as headache, confusion or delirium, fever, encephalitis, vomiting, hemiparesis, seizures, and loss of vision. Antibiotics are given, and the HIV-infected patient will receive suppressive drug therapy for the remainder of their lives. Patients should avoid sources of infection by washing hands after handling raw meat, avoid ingesting raw or undercooked meat, wash raw fruits and vegetables before eating, avoid contact with soil, and avoid changing cat litter.
Cytomegalovirus (CMV) and herpes simplex virus (HSV) types 1 and 2 are viruses that can significantly affect AIDS patients. CMV is found in blood, saliva, breast milk, cervical secretions, semen, urine, and feces. It usually doesn’t cause symptoms in a person with an intact immune system, but in the HIV patient, symptoms include inflammatory reactions in the lungs, GI tract, liver, CNS, and eyes. CMV is a significant cause of blindness in the HIV patient. Antiviral drugs are given to treat the infection.
HSV type 1 is transmitted by oral and respiratory secretions, affecting the skin and mucous membranes, producing painful lesions.
HSV type 2 is transmitted by sexual contact, producing similar lesions but in the perineal area. When the infection spreads, it affects the brain, liver, and lungs, producing seizures, deafness, blindness, and death. Acyclovir is an effective antiviral to treat HSV.
Patients with HIV infection have a much higher risk of acquiring certain types of cancer compared to uninfected patients. Due to their weakened immune system, the body’s ability to fight infections that may lead to cancer is reduced. There are three cancers known as ‘AIDS-defining malignancies’ which mark the point at which an HIV infection has progressed to AIDS – these include Kaposi sarcoma, non-Hodgkin’s lymphoma, and cervical cancer. Other common malignancies in HIV patients include liver, anal, and lung cancer, and Hodgkin lymphoma.
There are some cancers that the HIV patient is not at increased risk for, including breast, colorectal, prostate, and many other common cancers. Thus, general screening guidelines should be followed as with all other patients.
To treat the opportunistic infections, patients may be given several antibiotics over extended periods, which simultaneously increase the occurrence of side effects and resistance to the antibiotics.
Highly active antiretroviral therapy (HAART) is the most effective means of preventing opportunistic infections in AIDS patients. It also reduces the incidence of Kaposi sarcoma and non-Hodgkin lymphoma in HIV patients. The standard treatment uses a combination of at least 3 drugs that suppress HIV replication in the body, therefore allowing some restoration of immune function. The goal of treatment is to prevent infection or reduce its severity, restore or preserve immune function, improve quality of life, and reduce mortality. However, the drug regimen is potent and compliance is difficult for patients, often due to the numerous side effects, drug toxicity, possible drug resistance, and cost or availability of therapy. HAART therapy must be taken every day for the rest of the patient’s life in order to help minimize drug resistance.
Before starting therapy, the nurse must assess the patient’s knowledge of HIV infection and transmission. The patient must understand HAART therapy and potential adverse reactions.
Once therapy is started, continue to teach the patient about opportunistic infections and complications. Counsel the patient to avoid substance abuse and unsafe sexual practices. Emphasize the importance of continuing their prescribed drug regimens and to report any adverse reactions experienced.
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