HIV AIDS history and symptoms: Difference between revisions
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}}</ref> The specific opportunistic infections that AIDS patients develop depend in part on the prevalence of these infections in the geographic area in which the patient lives. | }}</ref> The specific opportunistic infections that AIDS patients develop depend in part on the prevalence of these infections in the geographic area in which the patient lives. | ||
===Pulmonary | ===Pulmonary Infections=== | ||
[[Image:PCPxray.jpg|thumb|left|150px|X-ray of [[Pneumocystis pneumonia (PCP)|''Pneumocystis jirovecii'']] caused pneumonia. There is increased white (opacity) in the lower lungs on both sides, characteristic of ''Pneumocystis'' pneumonia]] | [[Image:PCPxray.jpg|thumb|left|150px|X-ray of [[Pneumocystis pneumonia (PCP)|''Pneumocystis jirovecii'']] caused pneumonia. There is increased white (opacity) in the lower lungs on both sides, characteristic of ''Pneumocystis'' pneumonia]] | ||
[[Pneumocystis pneumonia (PCP)|Pneumocystis pneumonia]] (originally known as ''Pneumocystis carinii'' pneumonia, and still abbreviated as PCP, which now stands for '''P'''neumo'''c'''ystis '''p'''neumonia) is relatively rare in healthy, [[immunocompetent]] people, but common among HIV-infected individuals. It is caused by [[Pneumocystis pneumonia (PCP)|''Pneumocystis jirovecii'']]. Before the advent of effective diagnosis, treatment and routine [[prophylaxis]] in Western countries, it was a common immediate cause of death. In developing countries, it is still one of the first indications of AIDS in untested individuals, although it does not generally occur unless the CD4 count is less than 200 per µL.<ref name=Feldman>{{ | [[Pneumocystis pneumonia (PCP)|Pneumocystis pneumonia]] (originally known as ''Pneumocystis carinii'' pneumonia, and still abbreviated as PCP, which now stands for '''P'''neumo'''c'''ystis '''p'''neumonia) is relatively rare in healthy, [[immunocompetent]] people, but common among HIV-infected individuals. It is caused by [[Pneumocystis pneumonia (PCP)|''Pneumocystis jirovecii'']]. Before the advent of effective diagnosis, treatment and routine [[prophylaxis]] in Western countries, it was a common immediate cause of death. In developing countries, it is still one of the first indications of AIDS in untested individuals, although it does not generally occur unless the CD4 count is less than 200 per µL.<ref name=Feldman>{{ | ||
Revision as of 14:20, 5 November 2012
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Acquired immune deficiency syndrome (AIDS) is a collection of symptoms and infections resulting from the specific damage to the immune system caused by the human immunodeficiency virus (HIV) in humans,[1] and similar viruses in other species (SIV, FIV, etc.).
History and Symptoms
The symptoms of AIDS are primarily the result of conditions that do not normally develop in individuals with healthy immune systems. Most of these conditions are infections caused by bacteria, viruses, fungi and parasites that are normally controlled by the elements of the immune system that HIV damages. Opportunistic infections are common in people with AIDS.[2] HIV affects nearly every organ system. People with AIDS also have an increased risk of developing various cancers such as Kaposi's sarcoma, cervical cancer and cancers of the immune system known as lymphomas.
Additionally, people with AIDS often have systemic symptoms of infection like fevers, sweats (particularly at night), swollen glands, chills, weakness, and weight loss.[3][4] After the diagnosis of AIDS is made, the current average survival time with antiretroviral therapy (as of 2005) is estimated to be more than 5 years,[5] but because new treatments continue to be developed and because HIV continues to evolve resistance to treatments, estimates of survival time are likely to continue to change. Without antiretroviral therapy, death normally occurs within a year. Most patients die from opportunistic infections or malignancies associated with the progressive failure of the immune system.[6]
The rate of clinical disease progression varies widely between individuals and has been shown to be affected by many factors such as host susceptibility and immune function health care and co-infections,[6] as well as factors relating to the viral strain.[7][8] The specific opportunistic infections that AIDS patients develop depend in part on the prevalence of these infections in the geographic area in which the patient lives.
Pulmonary Infections
Pneumocystis pneumonia (originally known as Pneumocystis carinii pneumonia, and still abbreviated as PCP, which now stands for Pneumocystis pneumonia) is relatively rare in healthy, immunocompetent people, but common among HIV-infected individuals. It is caused by Pneumocystis jirovecii. Before the advent of effective diagnosis, treatment and routine prophylaxis in Western countries, it was a common immediate cause of death. In developing countries, it is still one of the first indications of AIDS in untested individuals, although it does not generally occur unless the CD4 count is less than 200 per µL.[9]
Tuberculosis (TB) is unique among infections associated with HIV because it is transmissible to immunocompetent people via the respiratory route, is easily treatable once identified, may occur in early-stage HIV disease, and is preventable with drug therapy. However, multidrug resistance is a potentially serious problem. Even though its incidence has declined because of the use of directly observed therapy and other improved practices in Western countries, this is not the case in developing countries where HIV is most prevalent. In early-stage HIV infection (CD4 count >300 cells per µL), TB typically presents as a pulmonary disease. In advanced HIV infection, TB often presents atypically with extrapulmonary (systemic) disease a common feature. Symptoms are usually constitutional and are not localized to one particular site, often affecting bone marrow, bone, urinary and gastrointestinal tracts, liver, regional lymph nodes, and the central nervous system.[10]
Gastrointestinal infections
Esophagitis is an inflammation of the lining of the lower end of the esophagus (gullet or swallowing tube leading to the stomach). In HIV infected individuals, this is normally due to fungal (candidiasis) or viral (herpes simplex-1 or cytomegalovirus) infections. In rare cases, it could be due to mycobacteria.[11]
Unexplained chronic diarrhea in HIV infection is due to many possible causes, including common bacterial (Salmonella, Shigella, Listeria, Campylobacter, or Escherichia coli) and parasitic infections; and uncommon opportunistic infections such as cryptosporidiosis, microsporidiosis, Mycobacterium avium complex (MAC) and cytomegalovirus (CMV) colitis. In some cases, diarrhea may be a side effect of several drugs used to treat HIV, or it may simply accompany HIV infection, particularly during primary HIV infection. It may also be a side effect of antibiotics used to treat bacterial causes of diarrhea (common for Clostridium difficile). In the later stages of HIV infection, diarrhea is thought to be a reflection of changes in the way the intestinal tract absorbs nutrients, and may be an important component of HIV-related wasting.[12]
Neurological diseases
Toxoplasmosis is a disease caused by the single-celled parasite called Toxoplasma gondii; it usually infects the brain causing toxoplasma encephalitis but it can infect and cause disease in the eyes and lungs.[13]
Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease, in which the gradual destruction of the myelin sheath covering the axons of nerve cells impairs the transmission of nerve impulses. It is caused by a virus called JC virus which occurs in 70% of the population in latent form, causing disease only when the immune system has been severely weakened, as is the case for AIDS patients. It progresses rapidly, usually causing death within months of diagnosis.[14] AIDS dementia complex (ADC) is a metabolic encephalopathy induced by HIV infection and fueled by immune activation of HIV infected brain macrophages and microglia which secrete neurotoxins of both host and viral origin.[15] Specific neurological impairments are manifested by cognitive, behavioral, and motor abnormalities that occur after years of HIV infection and is associated with low CD4+ T cell levels and high plasma viral loads. Prevalence is 10–20% in Western countries[16] but only 1–2% of HIV infections in India.[17][18] This difference is possibly due to the HIV subtype in India.
Cryptococcal meningitis is an infection of the meninx (the membrane covering the brain and spinal cord) by the fungus Cryptococcus neoformans. It can cause fevers, headache, fatigue, nausea, and vomiting. Patients may also develop seizures and confusion; left untreated, it can be lethal.
Tumors and malignancies
Patients with HIV infection have substantially increased incidence of several malignant cancers. This is primarily due to co-infection with an oncogenic DNA virus, especially Epstein-Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV), and human papillomavirus (HPV).[19][20]
Kaposi's sarcoma (KS) is the most common tumor in HIV-infected patients. The appearance of this tumor in young homosexual men in 1981 was one of the first signals of the AIDS epidemic. Caused by a gammaherpes virus called Kaposi's sarcoma-associated herpes virus (KSHV), it often appears as purplish nodules on the skin, but can affect other organs, especially the mouth, gastrointestinal tract, and lungs.
High-grade B cell lymphomas such as Burkitt's lymphoma, Burkitt's-like lymphoma, diffuse large B-cell lymphoma (DLBCL), and primary central nervous system lymphoma present more often in HIV-infected patients. These particular cancers often foreshadow a poor prognosis. In some cases these lymphomas are AIDS-defining. Epstein-Barr virus (EBV) or KSHV cause many of these lymphomas.
Cervical cancer in HIV-infected women is considered AIDS-defining. It is caused by human papillomavirus (HPV).[21]
In addition to the AIDS-defining tumors listed above, HIV-infected patients are at increased risk of certain other tumors, such as Hodgkin's disease and anal and rectal carcinomas. However, the incidence of many common tumors, such as breast cancer or colon cancer, does not increase in HIV-infected patients. In areas where HAART is extensively used to treat AIDS, the incidence of many AIDS-related malignancies has decreased, but at the same time malignant cancers overall have become the most common cause of death of HIV-infected patients.[22]
Other opportunistic infections
AIDS patients often develop opportunistic infections that present with non-specific symptoms, especially low-grade fevers and weight loss. These include infection with Mycobacterium avium-intracellulare and cytomegalovirus (CMV). CMV can cause colitis, as described above, and CMV retinitis can cause blindness. Penicilliosis due to Penicillium marneffei is now the third most common opportunistic infection (after extrapulmonary tuberculosis and cryptococcosis) in HIV-positive individuals within the endemic area of Southeast Asia.[23]
References
- ↑ "The Relationship Between the Human Immunodeficiency Virus and the Acquired Immunodeficiency Syndrome". NIAID. Retrieved 2008-03-10.
- ↑ Holmes CB, Losina E, Walensky RP, Yazdanpanah Y, Freedberg KA (2003). "Review of human immunodeficiency virus type 1-related opportunistic infections in sub-Saharan Africa". Clin. Infect. Dis. 36 (5): 656&ndash, 662. PMID 12594648.
- ↑ Guss DA (1994). "The acquired immune deficiency syndrome: an overview for the emergency physician, Part 1". J. Emerg. Med. 12 (3): 375&ndash, 384. PMID 8040596.
- ↑ Guss DA (1994). "The acquired immune deficiency syndrome: an overview for the emergency physician, Part 2". J. Emerg. Med. 12 (4): 491&ndash, 497. PMID 7963396.
- ↑ Schneider MF, Gange SJ, Williams CM, Anastos K, Greenblatt RM, Kingsley L, Detels R, Munoz A (2005). "Patterns of the hazard of death after AIDS through the evolution of antiretroviral therapy: 1984–2004". AIDS. 19 (17): 2009&ndash, 2018. PMID 16260908.
- ↑ 6.0 6.1 Lawn SD (2004). "AIDS in Africa: the impact of coinfections on the pathogenesis of HIV-1 infection". J. Infect. Dis. 48 (1): 1&ndash, 12. PMID 14667787.
- ↑ Campbell GR, Watkins JD, Esquieu D, Pasquier E, Loret EP, Spector SA (2005). "The C terminus of HIV-1 Tat modulates the extent of CD178-mediated apoptosis of T cells". J. Biol. Chem. 280 (46): 38376&ndash, 39382. PMID 16155003.
- ↑ Senkaali D, Muwonge R, Morgan D, Yirrell D, Whitworth J, Kaleebu P (2005). "The relationship between HIV type 1 disease progression and V3 serotype in a rural Ugandan cohort". AIDS Res. Hum. Retroviruses. 20 (9): 932&ndash, 937. PMID 15585080.
- ↑ Feldman C (2005). "Pneumonia associated with HIV infection". Curr. Opin. Infect. Dis. 18 (2): 165&ndash, 170. PMID 15735422.
- ↑ Decker CF, Lazarus A (2000). "Tuberculosis and HIV infection. How to safely treat both disorders concurrently". Postgrad Med. 108 (2): 57&ndash, 60, 65&ndash, 68. PMID 10951746.
- ↑ Zaidi SA, Cervia JS (2002). "Diagnosis and management of infectious esophagitis associated with human immunodeficiency virus infection". J. Int. Assoc. Physicians AIDS Care (Chic Ill). 1 (2): 53&ndash, 62. PMID 12942677.
- ↑ Guerrant RL, Hughes JM, Lima NL, Crane J (1990). "Diarrhea in developed and developing countries: magnitude, special settings, and etiologies". Rev. Infect. Dis. 12 (Suppl 1): S41&ndash, S50. PMID 2406855.
- ↑ Luft BJ, Chua A (2000). "Central Nervous System Toxoplasmosis in HIV Pathogenesis, Diagnosis, and Therapy". Curr. Infect. Dis. Rep. 2 (4): 358&ndash, 362. PMID 11095878.
- ↑ Sadler M, Nelson MR (1997). "Progressive multifocal leukoencephalopathy in HIV". Int. J. STD AIDS. 8 (6): 351&ndash, 357. PMID 9179644.
- ↑ Gray F, Adle-Biassette H, Chrétien F, Lorin de la Grandmaison G, Force G, Keohane C (2001). "Neuropathology and neurodegeneration in human immunodeficiency virus infection. Pathogenesis of HIV-induced lesions of the brain, correlations with HIV-associated disorders and modifications according to treatments". Clin. Neuropathol. 20 (4): 146&ndash, 155. PMID 11495003.
- ↑ Grant I, Sacktor H, McArthur J (2005). "HIV neurocognitive disorders" (PDF). In H. E. Gendelman, I. Grant, I. Everall, S. A. Lipton, and S. Swindells. (ed.). The Neurology of AIDS (PDF)
|format=requires|url=(help) (2nd ed.). London, UK: Oxford University Press. pp. 357&ndash, 373. ISBN 0-19-852610-5. - ↑ Satishchandra P, Nalini A, Gourie-Devi M; et al. (2000). "Profile of neurologic disorders associated with HIV/AIDS from Bangalore, South India (1989–1996)". Indian J. Med. Res. 11: 14&ndash, 23. PMID 10793489.
- ↑ Wadia RS, Pujari SN, Kothari S, Udhar M, Kulkarni S, Bhagat S, Nanivadekar A (2001). "Neurological manifestations of HIV disease". J. Assoc. Physicians India. 49: 343&ndash, 348. PMID 11291974.
- ↑ Boshoff C, Weiss R (2002). "AIDS-related malignancies". Nat. Rev. Cancer. 2 (5): 373&ndash, 382. PMID 12044013.
- ↑ Yarchoan R, Tosatom G, Littlem RF (2005). "Therapy insight: AIDS-related malignancies — the influence of antiviral therapy on pathogenesis and management". Nat. Clin. Pract. Oncol. 2 (8): 406&ndash, 415. PMID 16130937.
- ↑ Palefsky J (2007). "Human papillomavirus infection in HIV-infected persons". Top HIV Med. 15 (4): 130–3. PMID 17720998.
- ↑ Bonnet F, Lewden C, May T; et al. (2004). "Malignancy-related causes of death in human immunodeficiency virus-infected patients in the era of highly active antiretroviral therapy". Cancer. 101 (2): 317&ndash, 324. PMID 15241829.
- ↑ Skoulidis F, Morgan MS, MacLeod KM (2004). "Penicillium marneffei: a pathogen on our doorstep?". J. R. Soc. Med. 97 (2): 394&ndash, 396. PMID 15286196.