AIDS-defining clinical condition

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AIDS-defining clinical conditions (also known as AIDS-defining illnesses or AIDS-defining diseases) is the list of diseases published by the Centers for Disease Control and Prevention (CDC) that are associated with AIDS and used worldwide as a guideline for AIDS diagnosis. CDC exclusively uses the term AIDS-defining clinical conditions, but the other terms remain in common use.

Contents

This list governs the US government's classification of HIV disease. This is to allow the government to handle epidemic statistics and define who receives US government assistance. However, considerable variation exists in the relative risk of death following different AIDS-defining clinical conditions.[ further explanation needed ]

Definition

According to the CDC definition, a patient has AIDS if they are infected with HIV and have either:[ citation needed ]

A patient presenting one of the above conditions but with laboratory evidence against HIV infection is not normally considered to have AIDS, but an AIDS diagnosis may be given if the patient has had Pneumocystis jirovecii pneumonia, and has not:[ citation needed ]

Defining illnesses

2008 definition

Are the following:[ citation needed ]

  1. Candidiasis of bronchi, trachea, or lungs
  2. Candidiasis esophageal
  3. Coccidioidomycosis, disseminated or extrapulmonary
  4. Cryptococcosis, extrapulmonary
  5. Cryptosporidiosis, chronic intestinal for longer than 1 month
  6. Cytomegalovirus disease (other than liver, spleen or lymph nodes)
  7. Cytomegalovirus retinitis (with loss of vision)
  8. Encephalopathy (HIV-related)
  9. Herpes simplex : chronic ulcer(s) (for more than 1 month); or bronchitis, pneumonitis, or esophagitis
  10. Histoplasmosis, disseminated or extrapulmonary
  11. Isosporiasis, chronic intestinal (for more than 1 month)
  12. Kaposi's sarcoma
  13. Lymphoma, Burkitt's
  14. Lymphoma, immunoblastic (or equivalent term)
  15. Lymphoma, primary, of brain
  16. Mycobacterium avium complex or Mycobacterium kansasii , disseminated or extrapulmonary
  17. Mycobacterium , other species, disseminated or extrapulmonary
  18. Mycobacterium tuberculosis , any site (extrapulmonary)
  19. Pneumocystis jirovecii pneumonia (formerly Pneumocystis carinii)
  20. Progressive multifocal leukoencephalopathy
  21. Salmonella sepsis (recurrent)
  22. Toxoplasmosis of the brain
  23. Tuberculosis, disseminated
  24. Wasting syndrome due to HIV

Added in 1993

  1. Cervical cancer (invasive)
  2. Mycobacterium tuberculosis , any site (pulmonary)
  3. Pneumonia (recurrent)

Children < 13 years

Additional conditions are included for children younger than 13: [1]

History

In 1993, the CDC added pulmonary tuberculosis, recurrent pneumonia and invasive cervical cancer [2] to the list of clinical conditions in the AIDS surveillance case definition published in 1987 [3] and expanded the AIDS surveillance case definition to include all HIV-infected persons with CD4+ T-lymphocyte counts of fewer than 200 cells/μL or a CD4+ percentage of less than 14. Outside the US, however, diagnosis with a listed opportunistic infection is still required.[ citation needed ]

It has been suggested that other conditions (such as penicilliosis) should be included in other countries. [4]

Common Defining Conditions

Kaposi's Sarcoma

Kaposi's Sarcoma (KS) is an extremely common disease that arises in AIDS patients and HIV-infected individuals. The condition is characterized by large purple lesions on the skin and mouth. KS presents itself differently for everyone affected by it, and its symptoms and progression varies from person to person as well. [5] There are four different populations that are at risk for KS, all of which are caused by infection with human herpesvirus 8. In the United States, almost every case of Kaposi's Sarcoma is indirectly caused by HIV infection. The disease is the most common among male homosexuals, presumably because human herpesvirus 8 exists with the most prevalence within this population.

The remaining types of KS are known as Classic (Mediterranean), Endemic (African), and Transplant-related Kaposi's Sarcoma. Classic KS is common in regions of the Middle East, where herpesvirus 8 is fairly prevalent. KS occurrences in these regions are mainly found in older men, which is thought to be due to the natural decline of the immune system's strength when we age. Endemic KS presents itself the same way, but is a result of many people in certain regions of Africa being infected with human herpesvirus 8. In contrast to older men being affected in Classical infections, Endemic KS mainly affects young children, as the virus is transferred from mother to child via saliva. The final type of KS, transplant-related, is theoretically capable of manifesting in anyone. Transplant patients must take very strong immunosuppressant drugs to ensure that the body does not reject their new heart, liver, etc. However, a consequence of this is, of course, that their immune system becomes quite weak, and therefore very susceptible to infections. In a similar manner to how HIV contributes to KS, transplant patients are also at high risk for it, especially if the transplant was performed in a country where human herpesvirus 8 is endemic. [6] In recent years, however, incidences of Kaposi's sarcoma in the United States have dwindled so much that physicians today often fail to consider it as a possibility when making diagnoses.

Toxoplasmosis

In the central nervous system, the most common AIDS-defining condition is toxoplasmosis. Caused by the parasite Toxoplasma gondii, toxoplasmosis in HIV-infected patients mainly presents as encephalitis, or inflammation of the brain, but can take other forms as well, such as inflammation of the retinas or lungs. Toxoplasma, like most parasites, carries out its infection in distinct stages of life. Strangely enough, while many tissues can harbor the parasite, it is only capable of reproducing sexually in cats. [7] Cats are carriers of the oocyst- the infective form of Toxoplasma Gondii. Once these oocysts have entered a human, they can differentiate into their next stage of life, the tachyzoite. These cells can invade our own, rapidly divide by means of binary fission, lose our cells, and travel throughout our bodies. As a result of the immune response that this invasion causes, the tachyzoites become dormant, forming cysts called bradyzoites that are commonly found in the brain and skeletal muscle. In immunocompromised patients, such as those with HIV, the infection becomes much more deadly, as without a consistent or strong enough immune response following bradyzoite formation, tachyzoites can escape from the cysts, facilitating further systemic infection and inflammation. [8] In physiologically typical individuals, the infection will generally be taken care of by the immune system, rarely causing any actual illness. In fact, it is estimated that in some areas of the world, more than sixty percent of people have been exposed to the Toxoplasma parasite in their lifetime. HIV patients, on the other hand, often suffer from intense pain, difficulty seeing and breathing, or partial blindness due to toxoplasmosis as a result of an insufficient immune response. [9]

Related Research Articles

The Duesberg hypothesis is the claim that AIDS is not caused by HIV, but instead that AIDS is caused by noninfectious factors such as recreational and pharmaceutical drug use and that HIV is merely a harmless passenger virus. The hypothesis was popularized by Peter Duesberg, a professor of biology at University of California, Berkeley, from whom the hypothesis gets its name. The scientific consensus is that the Duesberg hypothesis is incorrect and that HIV is the cause of AIDS. The most prominent supporters of the hypothesis are Duesberg himself, biochemist and vitamin proponent David Rasnick, and journalist Celia Farber. The scientific community generally contends that Duesberg's arguments in favor of the hypothesis are the result of cherry-picking predominantly outdated scientific data and selectively ignoring evidence that demonstrates HIV's role in causing AIDS.

<span class="mw-page-title-main">Toxoplasmosis</span> Protozoan parasitic disease

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii, an apicomplexan. Infections with toxoplasmosis are associated with a variety of neuropsychiatric and behavioral conditions. Occasionally, people may have a few weeks or months of mild, flu-like illness such as muscle aches and tender lymph nodes. In a small number of people, eye problems may develop. In those with a weak immune system, severe symptoms such as seizures and poor coordination may occur. If a woman becomes infected during pregnancy, a condition known as congenital toxoplasmosis may affect the child.

The spread of HIV/AIDS has affected millions of people worldwide; AIDS is considered a pandemic. The World Health Organization (WHO) estimated that in 2016 there were 36.7 million people worldwide living with HIV/AIDS, with 1.8 million new HIV infections per year and 1 million deaths due to AIDS. Misconceptions about HIV and AIDS arise from several different sources, from simple ignorance and misunderstandings about scientific knowledge regarding HIV infections and the cause of AIDS to misinformation propagated by individuals and groups with ideological stances that deny a causative relationship between HIV infection and the development of AIDS. Below is a list and explanations of some common misconceptions and their rebuttals.

<span class="mw-page-title-main">Cryptococcosis</span> Potentially fatal fungal disease

Cryptococcosis is a potentially fatal fungal infection of mainly the lungs, presenting as a pneumonia, and brain, where it appears as a meningitis. Cough, difficulty breathing, chest pain and fever are seen when the lungs are infected. When the brain is infected, symptoms include headache, fever, neck pain, nausea and vomiting, light sensitivity and confusion or changes in behavior. It can also affect other parts of the body including skin, where it may appear as several fluid-filled nodules with dead tissue.

<span class="mw-page-title-main">Kaposi's sarcoma-associated herpesvirus</span> Species of virus

Kaposi's sarcoma-associated herpesvirus (KSHV) is the ninth known human herpesvirus; its formal name according to the International Committee on Taxonomy of Viruses (ICTV) is Human gammaherpesvirus 8, or HHV-8 in short. Like other herpesviruses, its informal names are used interchangeably with its formal ICTV name. This virus causes Kaposi's sarcoma, a cancer commonly occurring in AIDS patients, as well as primary effusion lymphoma, HHV-8-associated multicentric Castleman's disease and KSHV inflammatory cytokine syndrome. It is one of seven currently known human cancer viruses, or oncoviruses. Even after many years since the discovery of KSHV/HHV8, there is no known cure for KSHV associated tumorigenesis.

This is a list of AIDS-related topics, many of which were originally taken from the public domain U.S. Department of Health Glossary of HIV/AIDS-Related Terms, 4th Edition.

This is a timeline of HIV/AIDS, including cases before 1980.

<span class="mw-page-title-main">Opportunistic infection</span> Infection caused by pathogens that take advantage of an opportunity not normally available

An opportunistic infection is an infection caused by pathogens that take advantage of an opportunity not normally available. These opportunities can stem from a variety of sources, such as a weakened immune system, an altered microbiome, or breached integumentary barriers. Many of these pathogens do not necessarily cause disease in a healthy host that has a non-compromised immune system, and can, in some cases, act as commensals until the balance of the immune system is disrupted. Opportunistic infections can also be attributed to pathogens which cause mild illness in healthy individuals but lead to more serious illness when given the opportunity to take advantage of an immunocompromised host.

WHO Disease Staging System for HIV Infection and Disease in Adults and Adolescents was first produced in 1990 by the World Health Organization and updated in September 2005. It is an approach for use in resource limited settings and is widely used in Africa and Asia and has been a useful research tool in studies of progression to symptomatic HIV disease.

The current staging system for HIV infection in children was developed in 2005 and builds upon the staging system in place since 1987. A child is defined as someone under the age of 15. This staging system also requires the presence of HIV infection: HIV antibody for children aged 18 months or more; virological or p24 antigen positive test if aged under 18 months.

The CDC Classification System for HIV Infection is the medical classification system used by the United States Centers for Disease Control and Prevention (CDC) to classify HIV disease and infection. The system is used to allow the government to handle epidemic statistics and define who receives US government assistance.

Immune reconstitution inflammatory syndrome (IRIS) is a condition seen in some cases of HIV/AIDS or immunosuppression, in which the immune system begins to recover, but then responds to a previously acquired opportunistic infection with an overwhelming inflammatory response that paradoxically makes the symptoms of infection worse.

<span class="mw-page-title-main">Primary effusion lymphoma</span> Medical condition

Primary effusion lymphoma (PEL) is classified as a diffuse large B cell lymphoma. It is a rare malignancy of plasmablastic cells that occurs in individuals that are infected with the Kaposi's sarcoma-associated herpesvirus. Plasmablasts are immature plasma cells, i.e. lymphocytes of the B-cell type that have differentiated into plasmablasts but because of their malignant nature do not differentiate into mature plasma cells but rather proliferate excessively and thereby cause life-threatening disease. In PEL, the proliferating plasmablastoid cells commonly accumulate within body cavities to produce effusions, primarily in the pleural, pericardial, or peritoneal cavities, without forming a contiguous tumor mass. In rare cases of these cavitary forms of PEL, the effusions develop in joints, the epidural space surrounding the brain and spinal cord, and underneath the capsule which forms around breast implants. Less frequently, individuals present with extracavitary primary effusion lymphomas, i.e., solid tumor masses not accompanied by effusions. The extracavitary tumors may develop in lymph nodes, bone, bone marrow, the gastrointestinal tract, skin, spleen, liver, lungs, central nervous system, testes, paranasal sinuses, muscle, and, rarely, inside the vasculature and sinuses of lymph nodes. As their disease progresses, however, individuals with the classical effusion-form of PEL may develop extracavitary tumors and individuals with extracavitary PEL may develop cavitary effusions.

<span class="mw-page-title-main">Patrick S. Moore</span> Irish and American virologist and epidemiologist

Patrick S. Moore is an American virologist and epidemiologist who co-discovered together with his wife, Yuan Chang, two different human viruses causing the AIDS-related cancer Kaposi's sarcoma and the skin cancer Merkel cell carcinoma. Moore and Chang have discovered two of the seven known human viruses causing cancer. The couple met while in medical school together and were married in 1989 while they pursued fellowships at different universities.

<span class="mw-page-title-main">HIV/AIDS</span> Spectrum of conditions caused by HIV infection

HIV is a retrovirus that attacks the immune system. It can be managed with treatment. Without treatment it can lead to a spectrum of conditions including AIDS.

<span class="mw-page-title-main">Idiopathic CD4+ lymphocytopenia</span> Medical condition

Idiopathic CD4+ lymphocytopenia (ICL) is a rare medical syndrome in which the body has too few CD4+ T lymphocytes, which are a kind of white blood cell. ICL is sometimes characterized as "HIV-negative AIDS", though, in fact, its clinical presentation differs somewhat from that seen with HIV/AIDS. People with ICL have a weakened immune system and are susceptible to opportunistic infections, although the rate of infections is lower than in people with AIDS.

<i>Pneumocystis</i> pneumonia Medical condition

Pneumocystis pneumonia (PCP), also known as Pneumocystis jirovecii pneumonia (PJP), is a form of pneumonia that is caused by the yeast-like fungus Pneumocystis jirovecii.

<span class="mw-page-title-main">Kaposi's sarcoma</span> Cancer of the skin, integumentary lymph nodes, or other organs

Kaposi's sarcoma (KS) is a type of cancer that can form masses in the skin, in lymph nodes, in the mouth, or in other organs. The skin lesions are usually painless, purple and may be flat or raised. Lesions can occur singly, multiply in a limited area, or may be widespread. Depending on the sub-type of disease and level of immune suppression, KS may worsen either gradually or quickly. Except for Classical KS where there is generally no immune suppression, KS is caused by a combination of immune suppression and infection by Human herpesvirus 8.

<span class="mw-page-title-main">Signs and symptoms of HIV/AIDS</span>

The stages of HIV infection are acute infection, latency, and AIDS. Acute infection lasts for several weeks and may include symptoms such as fever, swollen lymph nodes, inflammation of the throat, rash, muscle pain, malaise, and mouth and esophageal sores. The latency stage involves few or no symptoms and can last anywhere from two weeks to twenty years or more, depending on the individual. AIDS, the final stage of HIV infection, is defined by low CD4+ T cell counts, various opportunistic infections, cancers, and other conditions.

<span class="mw-page-title-main">Plasmablastic lymphoma</span> Type of large B-cell lymphoma

Plasmablastic lymphoma (PBL) is a type of large B-cell lymphoma recognized by the World Health Organization (WHO) in 2017 as belonging to a subgroup of lymphomas termed lymphoid neoplasms with plasmablastic differentiation. The other lymphoid neoplasms within this subgroup are: plasmablastic plasma cell lymphoma ; primary effusion lymphoma that is Kaposi's sarcoma-associated herpesvirus positive or Kaposi's sarcoma-associated Herpesvirus negative; anaplastic lymphoma kinase-positive large B-cell lymphoma; and human herpesvirus 8-positive diffuse large B-cell lymphoma, not otherwise specified. All of these lymphomas are malignancies of plasmablasts, i.e. B-cells that have differentiated into plasmablasts but because of their malignant nature: fail to differentiate further into mature plasma cells; proliferate excessively; and accumulate in and injure various tissues and organs.

References

  1. Schneider E, Whitmore S, Glynn KM, Dominguez K, Mitsch A, McKenna MT (December 2008). "Revised surveillance case definitions for HIV infection among adults, adolescents, and children aged <18 months and for HIV infection and AIDS among children aged 18 months to <13 years--United States, 2008". MMWR Recomm Rep. 57 (RR-10): 1–12. PMID   19052530.
  2. "1993 revised classification system for HIV infection and expanded surveillance case definition for AIDS among adolescents and adults". MMWR. Recommendations and Reports : Morbidity and Mortality Weekly Report. Recommendations and Reports. 41 (RR-17): 1–19. 18 December 1992. PMID   1361652.
  3. Centers for Disease Control (CDC) (August 1987). "Revision of the CDC surveillance case definition for acquired immunodeficiency syndrome. Council of State and Territorial Epidemiologists; AIDS Program, Center for Infectious Diseases" (PDF). MMWR Morb. Mortal. Wkly. Rep. 36 (Suppl 1): 1S–15S. PMID   3039334.
  4. Lee N (April 2008). "Penicilliosis: an AIDS-defining disease in Asia". Hong Kong Med J. 14 (2): 88–9. PMID   18382013.
  5. Dezube, Bruce J. (October 1996). "Clinical Presentation and Natural History of Aids-Related Kaposi's Sarcoma". Hematology/Oncology Clinics of North America. 10 (5): 1023–1029. doi:10.1016/S0889-8588(05)70382-8. PMID   8880194.
  6. "Kaposi Sarcoma." Kaposi Sarcoma | Johns Hopkins Medicine, 8 Aug. 2021, https://www.hopkinsmedicine.org/health/conditions-and-diseases/sarcoma/kaposi-sarcoma.
  7. English, Elizabeth D.; Striepen, Boris (5 September 2019). "The cat is out of the bag: How parasites know their hosts". PLOS Biology. 17 (9): e3000446. doi: 10.1371/journal.pbio.3000446 . PMC   6748446 . PMID   31487278.
  8. Ayoade, Folusakin; Joel Chandranesan, Andrew Stevenson (2024). "HIV-1–Associated Toxoplasmosis". StatPearls. StatPearls Publishing. PMID   28722907.
  9. Basavaraju, Anuradha (2016). "Toxoplasmosis in HIV infection: An overview". Tropical Parasitology. 6 (2): 129–135. doi: 10.4103/2229-5070.190817 . PMC   5048699 . PMID   27722101.