AIDS occurs in patients who suffer from a severe and long unrecognized human immunodeficiency virus (HIV) infection (caused by either HIV-1 or HIV-2 virus) [1] [2] [3]. AIDS is almost never encountered in patients with an acute HIV infection, but rather develops after the period of latency and progressive decrease in CD4+T-cell function [4] [5]. One of the most important risk factors is the lack of treatment, mostly because of a missed (or unknown) diagnosis. The progressive nature of HIV infection symptoms and infections have been grouped into two diagnostic criteria devised by the Center for Disease Control (CDC) and the World Health Organization (WHO). As per CDC criteria, three distinct categories exist - A, B, and C, with A describing features of acute or asymptomatic HIV infection [2] [6]. On the other hand, categories B and C (similarly to clinical stages 2,3 and 4 of WHO criteria) include the appearance of AIDS-related conditions. Constitutional symptoms such as fever, fatigue, or diarrhea lasting for at least one month, peripheral neuropathy and numerous infections - Listeriosis, Bacillary angiomatosis, recurrent herpes zoster involving > 1 dermatome and pelvic inflammatory disease (PID) are initial signs of AIDS [1] [2] [3] [6] [7]. Candidiasis, however, is the most important group B feature of patients with suspected HIV or AIDS and can present in the oropharynx or the genitalia. Additional disorders that belong to the B category are immune thrombocytopenic purpura (ITP), cervical dysplasia (or cervical carcinoma in situ) and oral hairy leukoplakia. When patients present with profound weight loss and poor general condition due to "wasting syndrome" caused by HIV, they are adequately classified into category C and clinical stage 4, respectively, and signs of severe AIDS include [1] [2] [3] [6] [7]:

• Infections - Candidiasis (esophageal, pulmonary, or tracheal), pneumocystis jirovecii pneumonia (PCP), coccidiomycosis (either extrapulmonary or disseminated), extrapulmonary cryptococcosis, cytomegalovirus (CMV) infection of sites other than the spleen, lymph nodes or liver (such as pneumonia or retinitis), herpes simplex virus (HSV) infection of the respiratory system or the esophagus, histoplasmosis, intestinal isosporiasis, mycobacterial infections (both by tuberculous and by non-tuberculous mycobacteria, most notably M. avium), cerebral toxoplasmosis, recurrent pneumonias and severe infections by Salmonella spp.
• Malignancies - Lymphomas, Kaposi's sarcoma, and invasive cervical cancer.
• Other conditions - Progressive multifocal leukoencephalopathy (PML), HIV-related encephalopathy that can present with various neurological symptoms, including dementia (also known as the AIDS dementia complex).

• Generalized Lymphadenopathy

  Editorial Note Editorial Note: The report above documents the occurrence of cases of unexplained, persistent, generalized lymphadenopathy among homosexual males. [cdc.gov]

  Symptoms include generalized lymphadenopathy, fever, weight loss, and chronic diarrhea. [icd9data.com]

• Fever

  Pneumocystis carinii and fever improved immediately when ST mixture and highly active antiretroviral therapy (HAART) were performed. [ncbi.nlm.nih.gov]

• Weight Loss

  Here, I report the case of a 31-year-old immigrant Burmese woman who exhibited epigastralgia, fever, weight loss and an epigastric mass. [ncbi.nlm.nih.gov]

  loss, lymphadenopathy, and the occurrence of opportunistic infections and malignant tumours; abbreviated AIDS. [oxforddictionaries.com]

  They are also prone to wasting syndrome (involuntary weight loss), and memory impairment. [practo.com]

  You may have diarrhea, fever, weight loss, night sweats, or feel tired. Non-Hodgkin's lymphoma (lim-fo-muh) is a cancer that may effect AIDS patients. [drugs.com]

• Fatigue

  Fatigue was defined by patient self-report. The outcomes were the prevalence of fatigue and the potential risk factors of fatigue. [ncbi.nlm.nih.gov]

  Constitutional symptoms such as fever, fatigue, or diarrhea lasting for at least one month, peripheral neuropathy and numerous infections - Listeriosis, Bacillary angiomatosis, recurrent herpes zoster involving 1 dermatome and pelvic inflammatory disease [symptoma.com]

  Symptoms may include night sweats and fatigue, fever, cough, difficulty breathing, weight loss. Most likely to occur when the CD4 T cell count falls below 200. [conservapedia.com]

  Symptoms of acute HIV infection may include fever, arthralgia or myalgia, rash, lymphadenopathy, sore throat, fatigue, headache, oral ulcers and or genital ulcers, weight loss, nausea, vomiting or diarrhea. [simcoemuskokahealth.org]

  Eight months later, the donor complained of fatigue and decreased appetite. On examination, he had right axillary lymphadenopathy, and cotton-wool spots were seen in the retina of the left eye. [cdc.gov]

• Candidiasis

  Disseminated cryptococcosis and recurrent oral candidiasis was presented in a-heterosexual AIDS patient. [ncbi.nlm.nih.gov]

  tuberculosis, oral candidiasis, herpes zoster) to malignant neoplasms that cause, as well as result from, immunodeficiency((P)) (5). [cdc.gov]

  Candidiasis, however, is the most important group B feature of patients with suspected HIV or AIDS and can present in the oropharynx or the genitalia. [symptoma.com]

• Anemia

  In univariate analysis, the significant differences in demographic characteristics between patients with and without fatigue were: gender [OR 2.29; 95% CI (1.05-4.98)], education level [OR 0.40; 95% CI (0.18-0.85)], anemia [OR 3.80; 95% CI (1.27-11.31 [ncbi.nlm.nih.gov]

  At 14 months of age, the infant developed neutropenia and an autoimmune hemolytic anemia and thrombocytopenia. [cdc.gov]

• Cough

  A 33-year-old male presented with a history of fever and cough and was diagnosed to have pulmonary tuberculosis and acquired immunodeficiency syndrome (AIDS). [ncbi.nlm.nih.gov]

  This infection causes a long-term cough that may include coughing or spitting up blood. You may have fever, weight loss, or night sweats. Other signs depend upon the site of the infection. [drugs.com]

   Coughing or sneezing Sharing cups, plates and other eating utensils Sharing water or food Handshakes, touching or hugging Using the same toilet Insect bites 6. Sore throatFeverNight sweatingFatigueColdNausea 7. [slideshare.net]

  When people with lung TB cough, sneeze or spit, they propel the TB germs into the air. A person needs to inhale only a few of these germs to become infected. [who.int]

• Chronic Cough

  There may be a chronic cough with crepitations in both lungs. Hepatomegaly and splenomegaly may be detected in the abdomen. In infants, crusting around the anus may be a sign of chronic diarrhoea. [patient.info]

• Diarrhea

  […] patient is a 42-year-old male with a past medical history of HIV/AIDS (his most recent CD4 count, four months before admission, was 19) and hepatitis C who presented to the Emergency Department complaining of one week of persistent nausea, vomiting, and diarrhea [ncbi.nlm.nih.gov]

  Keywords: non-human primate, chronic diarrhea, aids, hiv, siv Abstract: Diarrhea is the pathophysiological reaction of hosts gastrointestinal tract to a variety of external stimuli. [doi.org]

  You may have diarrhea, fever, weight loss, night sweats, or feel tired. Non-Hodgkin's lymphoma (lim-fo-muh) is a cancer that may effect AIDS patients. [drugs.com]

• Chronic Diarrhea

  Because of its impact on the host immune system, acquired immune deficiency syndrome (AIDS) is currently the major cause of chronic diarrhea in many parts of the world. [doi.org]

  Symptoms include generalized lymphadenopathy, fever, weight loss, and chronic diarrhea. [icd9data.com]

  diarrhea for 1 month Unexplained persistent fever for 1 month ( 37.6 C, intermittent or constant) Persistent oral candidiasis (thrush) Oral hairy leukoplakia Pulmonary tuberculosis (current) Severe presumed bacterial infections (e.g., pneumonia, empyema [web.archive.org]

  diarrhea (over 1 month), diagnosed by histology or stool microscopy; (3) bronchial or pulmonary candidiasis, diagnosed by microscopy or by presence of characteristic white plaques grossly on the bronchial mucosa (not by culture alone); (4) non-Hodgkin's [cdc.gov]

• Failure to Thrive

  The clinical manifestations were failure to thrive; 9 children, persistent gastroenteritis; 8, recurrent fever; 5, bacterial infections; 5, hepatosplenomegaly; 5, candidiasis; 1, scabies; 1, skin rash; 2, tuberculous (TB) meningitis; 1 and paraplegia; [ncbi.nlm.nih.gov]

  The predominant clinical findings included failure to thrive, persistent infection of the oral mucosa by Candida albicans, chronic pulmonary infiltrates, hepatosplenomegaly, lymphadenopathy, and diarrhea. [nejm.org]

  As the disease progresses, characteristics are a general failure to thrive, anergy, and any of a variety of recurring infections, most commonly Pneumocystis pneumonia, tuberculosis, meningitis, and encephalitis caused by aspergillosis, candidiasis, cryptococcosis [medical-dictionary.thefreedictionary.com]

  Testing can be done within the first few months, but it is also important to recognize the early signs: recurrent infections and failure to thrive. [healthline.com]

  The common manifestations include failure to thrive, hepatosplenomegaly, pneumonia, diarrhea, oral candidiasis, lymphadenopathy, skin rashes, encephalopathy, parotitis, persistent fever, lymphoid interstitial pneumonitis, and recurrent bacterial infections [academic.oup.com]

• Loss of Appetite

  Several symptoms, such as weight loss and loss of appetite, were more common in our subjects with PHI. [aidsonline.com]

  […] of appetite, leading to a disproportionate loss of strength in different muscles in the body The CD4 lymphocyte count predicts the type of opportunistic infections and cancers an HIV-infected individual can develop as the count decreases Sometimes, an [dovemed.com]

  An overgrowth of yeast causes white patches on gums, tongue or lining of the mouth, pain, difficulty in swallowing and loss of appetite. Candida in the esophagus, trachea, bronchi or lungs is AIDS defining. [ucsfhealth.org]

  […] of appetite, caused by HIV itself Common with CD4 count below 50/mm 3 : Cytomegalovirus infection -- a viral infection that can affect almost any organ system, especially the large bowel and the eyes Mycobacterium avium -- a blood infection by a bacterium [web.archive.org]

• Perianal Ulcer

  Severe acquired immunodeficiency in male homosexuals, manifested by chronic perianal ulcerative herpes simplex lesions. N Engl J Med 1981;305:1439-44. Marmor M, Friedman-Kien AE, Laubenstein L., et al. [cdc.gov]

  Severe acquired immunodeficiency in male homosexuals, manifested by chronic perianal ulcerative herpes simplex lesions. N Engl J Med. 1981;305(24):1439–44. PubMed Google Scholar 14. [springerlink.com]

  ulcerative herpes simplex lesions. [dx.doi.org]

• Lesion of the Tongue

  The signs and symptoms of some of these infections may include: Sweats Chills Recurring fever Chronic diarrhea Swollen lymph glands Persistent white spots or unusual lesions on your tongue or in your mouth Persistent, unexplained fatigue Weakness Weight [mayoclinic.org]

• Social Isolation

  This includes having regular dental checks and their own accommodation. [ 19 ] There may be an element of social isolation and psychological issues may need to be addressed. [patient.info]

  Socially isolate yourself from that source. And stop reading political journalists to learn about a health issue. [theamericanconservative.com]

  Children orphaned due to AIDS-related deaths of parents or caregivers face an unpredictable future that is often compounded by the same stigma, discrimination, and social isolation faced by their parents/caregivers (12). [ifsw.org]

  Direct mechanisms are those that increase the likelihood of a person coming into contact with someone who is HIV positive, for example, through residential segregation and the social isolation of marginalized populations. [epirev.oxfordjournals.org]

  Generally, frequent or long‐term absence from work leads to job loss and may result in depression, financial insecurity, and social isolation ( Henderson 2005 ; Linn 1985 ). [doi.org]

• Sexual Dysfunction

  ''And we never find out about sexual dysfunction or about a grandparent who is afraid to touch his grandchild or about a patient who has to sit alone at family gatherings because everyone is afraid he'll give them AIDS.'' [nytimes.com]

• Peripheral Neuropathy

  Abstract Peripheral neuropathy is the most common neurological complication in HIV and is often associated with antiretroviral therapy. [ncbi.nlm.nih.gov]

  Peripheral neuropathy is the most common neurological complication in HIV and is often associated with antiretroviral therapy. [doi.org]

  Constitutional symptoms such as fever, fatigue, or diarrhea lasting for at least one month, peripheral neuropathy and numerous infections - Listeriosis, Bacillary angiomatosis, recurrent herpes zoster involving 1 dermatome and pelvic inflammatory disease [symptoma.com]

Because many disorders are a part of the clinical presentation of AIDS, physicians must maintain a high index of suspicion when any of the mentioned illnesses or infections appear together with a poor general condition. For this reason, a comprehensive workup is necessary to rule out HIV infection and AIDS as a possible cause [2]. Firstly, a detailed patient history must include assessment of potential risk factors such as unprotected sexual intercourse, particularly male homosexual (as the vast majority of patients in the developed world are males belonging to the men having sex with men - MSM population), contact with blood products (through intravenous drug use) or a positive family history in the setting of vertical transmission [2] [6] [7]. Moreover, the appearance of any of the infections (or their respective signs and symptoms) in recent months should be noted, and a detailed and complete physical examination may confirm cutaneous, pulmonary, or general manifestations of AIDS and warrant a laboratory investigation to diagnose the clinical entity. A neurological exam (including the mini-mental status examination) must be carried out in all patients suspected to have severe HIV infection, in order to assess the extent of neurological involvement and detect AIDS-related dementia. In addition to a complete blood count (CBC), which will show lymphopenia in virtually all patients, an extensive biochemical panel is necessary to evaluate organ status - lipid profile, liver and kidney function, and a full electrolyte panel [2] [3] [7]. If the diagnosis of HIV is not already known, testing for HIV antibodies is the first step in confirming this infection, followed by a CD4+T-cell count and isolation of viral RNA through polymerase chain reaction (PCR) analysis. Classification of patients harboring an HIV infection, supplementary to clinical criteria, is based on the CD4+T-cell count as well, and a number of < 200/µL is diagnostic for AIDS [2]. Additional recommended procedures include syphilis testing with the Venereal disease research laboratory test (VDRL) and rapid plasma reagin (RPR) tests, detection of anti-toxoplasma antibodies, purified protein derivative (PPD) test for tuberculosis, and determine possible coinfection by hepatitis viruses (A, B, or C) [3] [6] [7].

• Anergy

  Moreover, the findings of anergy and depressed T-lymphocyte helper-to-suppressor ratios in some of the patients with lymphadenopathy suggest cellular immune dysfunction. Patients with KS/OI have had severe abnormalities of cellular immunity (5,6). [cdc.gov]

  As the disease progresses, characteristics are a general failure to thrive, anergy, and any of a variety of recurring infections, most commonly Pneumocystis pneumonia, tuberculosis, meningitis, and encephalitis caused by aspergillosis, candidiasis, cryptococcosis [medical-dictionary.thefreedictionary.com]

• Hyponatremia

  Hyponatremia and MAI bacteremia were found in 58% of CMVE cases. Polymerase chain reaction (PCR) of CSF samples identified CMV genome in 33% of CMVE cases. [neurology.org]

• Hemoglobin Decreased

  Introduction Thalassemia is a general term for a group of congenital, genetic disorders characterized by low levels of hemoglobin, decreased red blood cell production, and anemia. [rarediseases.org]

• Lymphocytopenia

  CD4 lymphocytopenia among injecting drug users in New York City. J Acquir Immune Defic Syndr. 1993;6(7):820–2. PubMed Google Scholar 83. Donegan E, Stuart M, Niland JC, et al. [springerlink.com]

• Abnormal Renal Function

  The dose must be adjusted for abnormal renal function. Multiple randomized clinical trials indicate that TMP-SMX is as effective as parenteral pentamidine and more effective than other regimens. [cdc.gov]

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2. Mandell GL, Bennett JE, Dolin R. Mandel, Douglas and Bennett's Principles and Practice of Infectious Diseases. 8th ed. Philadelphia, Pennsylvania: Churchill Livingstone; 2015.
3. Porter RS, Kaplan JL. Merck Manual of Diagnosis and Therapy. 19th Edition. Merck Sharp & Dohme Corp. Whitehouse Station, N.J; 2011.
4. Ortblad KF, Lozano R, Murray CJL. The burden of HIV: insights from the Global Burden of Disease Study 2010. AIDS (London, England). 2013;27(13):2003-2017.
5. GBD 2015 HIV Collaborators. Estimates of global, regional, and national incidence, prevalence, and mortality of HIV, 1980–2015: the Global Burden of Disease Study 2015. Lancet HIV. 2016 Aug; 3(8):e361–e387.
6. Centers for Disease Control and Prevention (CDC). Revised surveillance case definition for HIV infection--United States, 2014. MMWR Recomm Rep. 2014;63(RR-03):1-10.
7. Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson J, Loscalzo J. eds. Harrison's Principles of Internal Medicine, 18e. New York, NY: McGraw-Hill; 2012.