HIV/AIDS

HIV/AIDS
SynonymsHIV disease, HIV infection[1][2][3]
A red ribbon in the shape of a bow
The red ribbon is a symbol for solidarity with HIV-positive people and those living with AIDS.[4]
SpecialtyInfectious disease
SymptomsEarly: flu like illness[5]
Later: Large lymph nodes, fever, weight loss[5]
ComplicationsOpportunistic infections, tumors[5]
DurationLong term[5]
CausesHuman immunodeficiency virus (HIV)[5]
Risk factorsExposure to blood, breast milk, sex[5]
Diagnostic methodBlood tests[5]
PreventionSafe sex, needle exchange, male circumcision, pre-exposure prophylaxis[5]
TreatmentAntiretroviral therapy[5]
PrognosisNear normal life expectancy with treatment[6][7]
Frequency1.8 million new cases (2016)[8]
36.7 million living with HIV (2016)[8]
Deaths1.0 million (2016)[8]

Human immunodeficiency virus infection and acquired immune deficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV).[9][10][11] Following initial infection, a person may not notice any symptoms or may experience a brief period of influenza-like illness.[5] Typically, this is followed by a prolonged period with no symptoms.[6] As the infection progresses, it interferes more with the immune system, increasing the risk of developing common infections such as tuberculosis, as well as other opportunistic infections, and tumors that rarely affect people who have working immune systems.[5] These late symptoms of infection are referred to as acquired immunodeficiency syndrome (AIDS).[6] This stage is often also associated with unintended weight loss.[6]

HIV is spread primarily by unprotected sex (including anal and oral sex), contaminated blood transfusions, hypodermic needles, and from mother to child during pregnancy, delivery, or breastfeeding.[12] Some bodily fluids, such as saliva and tears, do not transmit HIV.[13] Methods of prevention include safe sex, needle exchange programs, treating those who are infected, and male circumcision.[5] Disease in a baby can often be prevented by giving both the mother and child antiretroviral medication.[5] There is no cure or vaccine; however, antiretroviral treatment can slow the course of the disease and may lead to a near-normal life expectancy.[6][7] Treatment is recommended as soon as the diagnosis is made.[14] Without treatment, the average survival time after infection is 11 years.[15]

In 2016, about 36.7 million people were living with HIV and it resulted in 1 million deaths.[16] There were 300,000 fewer new HIV cases in 2016 than in 2015.[17] Most of those infected live in sub-Saharan Africa.[5] From the time AIDS was identified in the early 1980s to 2017, the disease has caused an estimated 35 million deaths worldwide.[18] HIV/AIDS is considered a pandemic—a disease outbreak which is present over a large area and is actively spreading.[19] HIV originated in west-central Africa during the late 19th or early 20th century.[20] AIDS was first recognized by the United States Centers for Disease Control and Prevention (CDC) in 1981 and its cause—HIV infection—was identified in the early part of the decade.[21]

HIV/AIDS has had a great impact on society, both as an illness and as a source of discrimination.[22] The disease also has large economic impacts.[22] There are many misconceptions about HIV/AIDS such as the belief that it can be transmitted by casual non-sexual contact.[23] The disease has become subject to many controversies involving religion including the Catholic Church's position not to support condom use as prevention.[24] It has attracted international medical and political attention as well as large-scale funding since it was identified in the 1980s.[25]

Signs and symptoms

There are three main stages of HIV infection: acute infection, clinical latency and AIDS.[1]

Acute infection

A diagram of a human torso labelled with the most common symptoms of an acute HIV infection
Main symptoms of acute HIV infection

The initial period following the contraction of HIV is called acute HIV, primary HIV or acute retroviral syndrome.[2][26] Many individuals develop an influenza-like illness or a mononucleosis-like illness 2–4 weeks after exposure while others have no significant symptoms.[27][28] Symptoms occur in 40–90% of cases and most commonly include fever, large tender lymph nodes, throat inflammation, a rash, headache, tiredness, and/or sores of the mouth and genitals.[26][28] The rash, which occurs in 20–50% of cases, presents itself on the trunk and is maculopapular, classically.[29] Some people also develop opportunistic infections at this stage.[26] Gastrointestinal symptoms, such as vomiting or diarrhea may occur.[28] Neurological symptoms of peripheral neuropathy or Guillain–Barré syndrome also occurs.[28] The duration of the symptoms varies, but is usually one or two weeks.[28]

Due to their nonspecific character, these symptoms are not often recognized as signs of HIV infection. Even cases that do get seen by a family doctor or a hospital are often misdiagnosed as one of the many common infectious diseases with overlapping symptoms. Thus, it is recommended that HIV be considered in people presenting with an unexplained fever who may have risk factors for the infection.[28]

Clinical latency

The initial symptoms are followed by a stage called clinical latency, asymptomatic HIV, or chronic HIV.[1] Without treatment, this second stage of the natural history of HIV infection can last from about three years[30] to over 20 years[31] (on average, about eight years).[32] While typically there are few or no symptoms at first, near the end of this stage many people experience fever, weight loss, gastrointestinal problems and muscle pains.[1] Between 50 and 70% of people also develop persistent generalized lymphadenopathy, characterized by unexplained, non-painful enlargement of more than one group of lymph nodes (other than in the groin) for over three to six months.[2]

Although most HIV-1 infected individuals have a detectable viral load and in the absence of treatment will eventually progress to AIDS, a small proportion (about 5%) retain high levels of CD4+ T cells (T helper cells) without antiretroviral therapy for more than 5 years.[28][33] These individuals are classified as "HIV controllers" or long-term nonprogressors (LTNP).[33] Another group consists of those who maintain a low or undetectable viral load without anti-retroviral treatment, known as "elite controllers" or "elite suppressors". They represent approximately 1 in 300 infected persons.[34]

Acquired immunodeficiency syndrome

A diagram of a human torso labelled with the most common symptoms of AIDS
Main symptoms of AIDS.

Acquired immunodeficiency syndrome (AIDS) is defined in terms of either a CD4+ T cell count below 200 cells per µL or the occurrence of specific diseases in association with an HIV infection.[28] In the absence of specific treatment, around half of people infected with HIV develop AIDS within ten years.[28] The most common initial conditions that alert to the presence of AIDS are pneumocystis pneumonia (40%), cachexia in the form of HIV wasting syndrome (20%), and esophageal candidiasis.[28] Other common signs include recurrent respiratory tract infections.[28]

Opportunistic infections may be caused by bacteria, viruses, fungi, and parasites that are normally controlled by the immune system.[35] Which infections occur depends partly on what organisms are common in the person's environment.[28] These infections may affect nearly every organ system.[36]

People with AIDS have an increased risk of developing various viral-induced cancers, including Kaposi's sarcoma, Burkitt's lymphoma, primary central nervous system lymphoma, and cervical cancer.[29] Kaposi's sarcoma is the most common cancer occurring in 10 to 20% of people with HIV.[37] The second most common cancer is lymphoma, which is the cause of death of nearly 16% of people with AIDS and is the initial sign of AIDS in 3 to 4%.[37] Both these cancers are associated with human herpesvirus 8 (HHV-8).[37] Cervical cancer occurs more frequently in those with AIDS because of its association with human papillomavirus (HPV).[37] Conjunctival cancer (of the layer that lines the inner part of eyelids and the white part of the eye) is also more common in those with HIV.[38]

Additionally, people with AIDS frequently have systemic symptoms such as prolonged fevers, sweats (particularly at night), swollen lymph nodes, chills, weakness, and unintended weight loss.[39] Diarrhea is another common symptom, present in about 90% of people with AIDS.[40] They can also be affected by diverse psychiatric and neurological symptoms independent of opportunistic infections and cancers.[41]

Other Languages
Afrikaans: Vigs
Alemannisch: AIDS
አማርኛ: ኤድስ
العربية: إيدز
aragonés: SIDA
অসমীয়া: এইড্‌ছ
asturianu: SIDA
azərbaycanca: QİÇS
تۆرکجه: ایدز
বাংলা: এইডস
Bân-lâm-gú: AIDS
башҡортса: ВИЧ-инфекция
беларуская: СНІД
беларуская (тарашкевіца)‎: СНІД
བོད་ཡིག: ཨེ་ཛིའི་ནད་
brezhoneg: SIDA
Чӑвашла: ЕИДП
čeština: AIDS
chiTumbuka: AIDS
Cymraeg: AIDS
dansk: AIDS
Deutsch: AIDS
ދިވެހިބަސް: އެއިޑްސް ބަލި
डोटेली: एड्स
eesti: AIDS
Ελληνικά: AIDS
español: VIH/sida
Esperanto: Aidoso
estremeñu: SIDA
فارسی: ایدز
Fiji Hindi: HIV/AIDS
føroyskt: Eyðkvæmi
Frysk: AIDS
furlan: AIDS
Gaeilge: SEIF
Gàidhlig: AIDS
galego: SIDA
贛語: 艾滋病
Gĩkũyũ: AIDS
ગુજરાતી: એઇડ્સ
客家語/Hak-kâ-ngî: AIDS
Hausa: Kanjamau
հայերեն: ՄԻԱՎ/ՁԻԱՀ
हिन्दी: एड्स
Ilokano: HIV/AIDS
Bahasa Indonesia: AIDS
interlingua: SIDA
íslenska: Alnæmi
italiano: AIDS
עברית: איידס
Basa Jawa: AIDS
Kabɩyɛ: Sidaa
ಕನ್ನಡ: ಏಡ್ಸ್ ರೋಗ
ქართული: შიდსი
қазақша: ЖИТС
Kiswahili: Ukimwi
Kongo: Sida
Kreyòl ayisyen: Sida
kurdî: AIDS
Кыргызча: СПИД
ລາວ: ເອດສ໌
Latina: SCDI
latviešu: AIDS
Lëtzebuergesch: Aids
лезги: КъИДС
lietuvių: AIDS
Limburgs: AIDS
lingála: Sidá
lumbaart: AIDS
magyar: AIDS
मैथिली: एड्स
മലയാളം: എയ്‌ഡ്‌സ്‌
Malti: AIDS
მარგალური: შიდსი
مصرى: ايدز
Mìng-dĕ̤ng-ngṳ̄: AIDS
မြန်မာဘာသာ: အေအိုင်ဒီအက်စ်
Nederlands: Aids
नेपाली: एड्स
नेपाल भाषा: एड्स
norsk: Aids
norsk nynorsk: Hiv/aids
occitan: SIDA
олык марий: НИДС
oʻzbekcha/ўзбекча: Orttirilgan immun tanqisligi sindromi
ਪੰਜਾਬੀ: ਏਡਜ਼
پنجابی: ایڈز
Papiamentu: Sida
پښتو: اېډز
Patois: AIDS
ភាសាខ្មែរ: ជំងឺអេដស៍
română: SIDA
русиньскый: АІДС
саха тыла: СПИД
संस्कृतम्: एइड्स्
Scots: HIV/AIDS
shqip: AIDS
sicilianu: AIDS
සිංහල: ඒඩ්ස්
Simple English: AIDS
سنڌي: ايڊز
slovenčina: Aids
slovenščina: Aids
Soomaaliga: AIDS
کوردی: ئایدز
српски / srpski: Сида
srpskohrvatski / српскохрватски: SIDA
Basa Sunda: AIDS
suomi: AIDS
svenska: Aids
Tagalog: AIDS
தமிழ்: எயிட்சு
татарча/tatarça: БИДС
తెలుగు: ఎయిడ్స్
ไทย: เอดส์
тоҷикӣ: СПИД
Tshivenda: CIDA
Türkçe: AIDS
Türkmençe: AIDS
Thuɔŋjäŋ: Adarwal
українська: СНІД
Vahcuengh: Bingh'aiswhbing
vèneto: AIDS
Tiếng Việt: HIV/AIDS
Võro: AIDS
walon: Sida
文言: 艾滋病
Winaray: HIV/AIDS
吴语: 艾滋病
Xitsonga: HIV/AIDS
ייִדיש: עידס
粵語: 愛滋病
Zazaki: AIDS
žemaitėška: AIDS
中文: 艾滋病