HIV: Opportunistic Infections Diagnosis

  • Diagnosis

    Opportunistic infections are infections that occur if you have a weakened immune system. Your immune system, when healthy, protects you from infections. People with human immunodeficiency virus (HIV) have weakened immune systems that are unable to fight certain infections. People with weakened immune systems can even get infections from organisms that don’t usually cause diseases in health people. HIV attacks specific cells in your immune system known as helper T cells. These white blood cells, also known as CD4 (or CD4+) cells, help to keep infection at bay. Having HIV reduces the numbers of these helpful cells in your body, and makes it harder for your immune system to fight off disease.

    HIV-related opportunistic infections can be caused by a wide variety of disease-causing microorganisms (pathogens). You can get an opportunistic infection from almost anywhere in the environment (for example, soil or water), from certain unwashed raw foods, from contact with animal feces, and in rare cases, from other people. You can also become sick if you carry certain dormant pathogens that reactivate as your immune system fails. If your immune system is particularly weak, you may want to avoid places such as daycare centers, dormitories, hospitals, or other places where germs may be common, or where the high concentration of people increases your likelihood of picking up an infection.

    Your symptoms will depend on the pathogen involved, the site of your infection, and the health of your immune system Table 01. HIV-related infections may affect any part of your body. Some opportunistic infections may also cause symptoms that spread through several areas of your body. In general, the healthier your immune system, the less severe the disease. For example, tuberculosis is usually confined to the lungs in people whose immune systems are still rather strong. As the immune system weakens, tuberculosis may spread outside the lungs to other areas of the body.

    Table 1.  Symptoms of Opportunistic Infections Associated with HIV

    Disease Symptoms
    Pneumonia Fever, fatigue, weight loss, cough, difficulty breathing, night sweats.
    Encephalitis Altered mental states, focal paralysis, seizures, severe headaches, fever.
    Gastroenteritis Diarrhea, abdominal cramping, nausea, vomiting, fatigue, gas, weight loss, loss of appetite, constipation, dehydration.
    Tuberculosis Cough, coughing up blood, weight loss, night sweats, fatigue, fever, swollen glands. May spread to central nervous system, gastrointestinal tract, or skeleton.
    Disseminated infection Fever, night sweats, fatigue, weight loss, diarrhea, anemia, abdominal pain, weakness, dizziness, nausea, enlarged glands, enlarged liver and spleen.
    Meningitis Headaches, stiffness in the neck, malaise, fever, nausea, fatigue, loss of appetite, altered mental status.
    Oral yeast infections White patches on the gums, tongue, or lining of the mouth; loss of appetite.
    Vaginal yeast infections Vaginal burning, itching, and discharge.
    Histoplasmosis Fever, weight loss, skin lesions, difficulty breathing, anemia, enlarged glands.
    CMV retinitis Vision loss, seeing ?floaters? or flashing lights.
    Enterocolitis Diarrhea, weight loss, abdominal pain.
    Encephalitis Headache, fever, focal paralysis, confusion, seizures.
    Pneumonitis Cough, difficulty breathing, fever, chest pain.
    Herpes simplex virus Painful blisters, ulcers, and/or itching on the lips, anus, or genitals.
    Shingles Itching, burning, painful blisters with that erupt in a discrete band on the skin, fever, muscle pain, malaise, rash.
    Kaposi's sarcoma Purple or deep-red skin lesions, most commonly on the face, genitals, extremities, and in the mouth; can also involve internal organs.
    Genital warts Warts on the genitals or anus.
    Anogenital neoplasia Cervical or anal cancer.
    Oral ?hairy? leukoplakia Painless white lesions (lines or plaques) on the sides of the tongue and insides of the cheeks.
    Nervous system tumor Confusion, slowness, personality changes, seizures.

    Your risk of developing opportunistic infections depends on the health of your immune system Table 02. The health of your immune system is measured by the number of a certain kind of white blood cell (CD4 cells) per microliter (µL) of blood.  The fewer CD4 cells you have, the more likely you are to get sick. Certain diseases are likely to occur at different levels of CD4 counts. For example, tuberculosis and oral thrush occur even in people whose immune systems are relatively healthy (CD4 counts >200/µL), while other infections usually don't appear until late in the course of HIV disease (CD4 counts <50/µL).

    Table 2.  Opportunistic Infections and CD4 T Cell Count in HIV Disease

    CD4 Count Disease
    200-500/?L Pneumonia (usually caused by bacteria)
    Tuberculosis in the lungs
    Oral or vaginal yeast infections
    Shingles (viral skin infection)
    Oral hairy leukoplakia
    Kaposi's sarcoma
    100-200/?L All of the above plus:
    Pneumonia due to Pneumocystis carinii (PCP)
    Chronic diarrhea
    50-100/?L All of the above, plus:
    Encephalitis (usually due to toxoplasmosis)
    Esophagitis due to yeast or viruses
    Meningitis (usually due to cryptococcus)
    Tuberculosis outside the lungs
    Chronic herpes simplex virus (HSV infection
    Primary brain? lymphoma
    <50/?L All of the above, plus:
    Widespread infection due to Mycobacterium avium complex
    Retinitis, diarrhea, encephalitis due to cytomegalovirus

    Engaging in unsafe sexual practices increases your risk of exposure to pathogens that cause HIV-related opportunistic infections.

    Having unprotected sex (sex without condoms) increases your risk of getting sexually transmitted diseases. In addition, engaging in sexual practices where your mouth comes in contact with your partner’s anus increases your risk of acquiring certain gastrointestinal and liver infections.

    Sharing needles or intravenous drugs puts you at serious risk of exposure to and infection with hepatitis B, hepatitis C, additional strains of HIV, and other blood-borne pathogens.

    During your first appointment, your clinician will ask you questions about your medical history. When you first seek treatment for HIV or an HIV-related opportunistic infection, your clinician will ask you questions to estimate when you were infected with the virus, and to identify other factors that may affect the progression of your disease.

    You doctor will ask you questions to identify any:

    • Symptoms related to HIV infection
    • Current medications you are taking and any allergies to medications
    • Past history of tuberculosis, hepatitis, or sexually transmitted diseases
    • HIV risk factors (e.g., sexual history, intravenous drug use)
    • Previous treatment with antiretrovirals
    • Previous immunizations
    • History of alcohol, tobacco, and illicit substance use
    • Current and previous exposure history—this will include a residence and travel history (within and outside the U.S.), occupational and recreational exposures to certain pathogens, pet ownership, hobbies (e.g. gardening), TB exposure, etc.

    Your clinician will then perform a full physical examination. Your doctor will examine several organs and systems of your body that may show symptoms of HIV-related opportunistic infections, including your skin, mouth, lymph nodes, genitals, lungs, and nervous system. Women should undergo a gynecologic exam with a Pap smear.

    Your doctor will order blood and other laboratory tests. Two different types of tests are used detect how far your HIV infection has progressed, and to estimate the health of your immune system. The first test counts the number of CD4 cells in your blood, the cells of the immune system that are infected and killed by HIV. CD4 cells play a critical role in fighting off infection and disease, and their numbers decline throughout the course of HIV infection. When your CD4 count becomes very low, your risk for opportunistic infection increases. Uninfected people have a CD4 count of about 1,000. If you have a CD4 count under 200, you have AIDS. Serious opportunistic infections can occur if your CD4 counts drops below 200.

    The second type of blood test measures the amount of HIV in your blood.  This test helps determine how fast your disease will progress.  It also helps your doctor determine when to begin or change your drug therapy, and can help to monitor how well a particular drug or drug combination is working. Your doctor may run specific tests to determine whether you have or have had particular infections including tuberculosis, cytomegalovirus, and hepatitis.  These tests may be blood tests, formal eye exams, or x-rays.

    There are three ways to prevent HIV-related opportunistic infections: 1) prevent yourself from being exposed to pathogens; 2) prevent the disease from developing if you have been exposed to a pathogen; and 3) prevent the disease from recurring if you have already had an episode. When possible, preventing yourself from being exposed to the pathogens that cause opportunistic infections is the best way to prevent disease.  However, many of the pathogens that cause infections are so widespread in the environment that there is no practical way to avoid contact with them.  In fact, if you are already infected with a common pathogen, prevention will consist of keeping the disease from reactivating.   This method involves using appropriate antimicrobial drugs when your CD4 count reaches a certain level. In people who have already developed opportunistic infections, the same or similar drugs that were used to treat the infection are often used to prevent a recurrence.

    Consistent and proper use of condoms during sex can reduce your risk of exposure to sexually transmitted pathogens. Latex and polyurethane condoms provide an impenetrable barrier against viruses and bacteria. Condoms should only be used before their expiration date, and when no obvious signs of defects or damage are visible. They should be worn before any sexual contact is made with the penis, and each condom should be used only once. Only water-based lubricants should be used with condoms. Petroleum jelly, vegetable oil, or other oil-based lubricants can damage the condom and cause it to tear.

    Injection drug users can reduce their risk of getting infections by not reusing or sharing needles. Using contaminated syringes and needles is one of the most common ways people become infected with HIV. It is also associated with a high risk of acquiring hepatitis B, C, and other bloodborne pathogens. People who continue to use intravenous drugs can reduce their risk of exposure to blood-borne pathogens by:

    • Not reusing or sharing needles, syringes, or drug preparation equipment
    • Using sterile water to prepare drugs
    • Using new or disinfected containers to prepare drugs
    • Using a sterile injection technique

    Avoid certain environmental or occupational exposures to reduce your risk of contracting pathogens that cause opportunistic infections. Child care providers, healthcare workers, and people who work with animals work in an environment where they are likely to come in contact with certain pathogens that can cause more severe or prolonged infections in people with compromised immune systems. It may not be appropriate for you to work in one of these situations or, if you do, you should strictly adhere to universal precautions (health care workers) and good hygienic practices (hand washing, gloves).

    Handle and prepare your food properly to reduce your risk of exposure to food- and water-borne pathogens. Raw or undercooked meat, unpasteurized dairy products, foods containing raw or undercooked eggs, and raw fruits and vegetables may carry intestinal pathogens. Water from lakes, rivers, pools, and other recreational sources may carry other pathogens. Thoroughly washing and cooking all foods, as well as thoroughly washing and disinfecting your hands, knives, cutting boards, and counters during food preparation can reduce your risk of exposure to these pathogens. You should also avoid swallowing water directly from lakes, streams, and swimming pools. In addition, avoid swimming in water that may be contaminated (for example, in swimming pools used by young children).

    Get immunized against certain bacterial and viral infections. The immunizations you should get depend on the health of your immune system and your previous exposure to bacteria and viruses. Examples of some possible vaccines include the pneumococcal vaccine, hepatitis A vaccine, hepatitis B, and the influenza vaccine. The pneumococcal vaccine is recommended for all people with HIV. Hepatitis A vaccine is recommended for anyone with a hepatitis C infection and for men who have sex with other men. Hepatitis B vaccine is recommended for people with hepatits C, and for people who are at increased risk for hepatitis B, such as healthcare workers and intravenous drug users.

    Your doctor may prescribe drugs to prevent infections based on your CD4 count, your risk of being exposed to pathogens, and your history of previous infections. Your doctor may also prescribe drugs to prevent an infection from recurring. If your CD4 count returns to normal as a result of HIV drug treatment, you may no longer need drugs to prevent other infections.

  • Prevention and Screening

    There are three ways to prevent HIV-related opportunistic infections: 1) prevent yourself from being exposed to pathogens; 2) prevent the disease from developing if you have been exposed to a pathogen; and 3) prevent the disease from recurring if you have already had an episode. When possible, preventing yourself from being exposed to the pathogens that cause opportunistic infections is the best way to prevent disease.  However, many of the pathogens that cause infections are so widespread in the environment that there is no practical way to avoid contact with them.  In fact, if you are already infected with a common pathogen, prevention will consist of keeping the disease from reactivating.   This method involves using appropriate antimicrobial drugs when your CD4 count reaches a certain level. In people who have already developed opportunistic infections, the same or similar drugs that were used to treat the infection are often used to prevent a recurrence.

    Consistent and proper use of condoms during sex can reduce your risk of exposure to sexually transmitted pathogens. Latex and polyurethane condoms provide an impenetrable barrier against viruses and bacteria. Condoms should only be used before their expiration date, and when no obvious signs of defects or damage are visible. They should be worn before any sexual contact is made with the penis, and each condom should be used only once. Only water-based lubricants should be used with condoms. Petroleum jelly, vegetable oil, or other oil-based lubricants can damage the condom and cause it to tear.

    Injection drug users can reduce their risk of getting infections by not reusing or sharing needles. Using contaminated syringes and needles is one of the most common ways people become infected with HIV. It is also associated with a high risk of acquiring hepatitis B, C, and other bloodborne pathogens. People who continue to use intravenous drugs can reduce their risk of exposure to blood-borne pathogens by:

    • Not reusing or sharing needles, syringes, or drug preparation equipment
    • Using sterile water to prepare drugs
    • Using new or disinfected containers to prepare drugs
    • Using a sterile injection technique

    Avoid certain environmental or occupational exposures to reduce your risk of contracting pathogens that cause opportunistic infections. Child care providers, healthcare workers, and people who work with animals work in an environment where they are likely to come in contact with certain pathogens that can cause more severe or prolonged infections in people with compromised immune systems. It may not be appropriate for you to work in one of these situations or, if you do, you should strictly adhere to universal precautions (health care workers) and good hygienic practices (hand washing, gloves).

    Handle and prepare your food properly to reduce your risk of exposure to food- and water-borne pathogens. Raw or undercooked meat, unpasteurized dairy products, foods containing raw or undercooked eggs, and raw fruits and vegetables may carry intestinal pathogens. Water from lakes, rivers, pools, and other recreational sources may carry other pathogens. Thoroughly washing and cooking all foods, as well as thoroughly washing and disinfecting your hands, knives, cutting boards, and counters during food preparation can reduce your risk of exposure to these pathogens. You should also avoid swallowing water directly from lakes, streams, and swimming pools. In addition, avoid swimming in water that may be contaminated (for example, in swimming pools used by young children).

    Get immunized against certain bacterial and viral infections. The immunizations you should get depend on the health of your immune system and your previous exposure to bacteria and viruses. Examples of some possible vaccines include the pneumococcal vaccine, hepatitis A vaccine, hepatitis B, and the influenza vaccine. The pneumococcal vaccine is recommended for all people with HIV. Hepatitis A vaccine is recommended for anyone with a hepatitis C infection and for men who have sex with other men. Hepatitis B vaccine is recommended for people with hepatits C, and for people who are at increased risk for hepatitis B, such as healthcare workers and intravenous drug users.

    Your doctor may prescribe drugs to prevent infections based on your CD4 count, your risk of being exposed to pathogens, and your history of previous infections. Your doctor may also prescribe drugs to prevent an infection from recurring. If your CD4 count returns to normal as a result of HIV drug treatment, you may no longer need drugs to prevent other infections.

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