Acquired immunodeficiency syndrome

Acquired immunodeficiency syndrome (AIDS) is caused by human immunodeficiency virus (HIV). Initial infection is followed by a period of no symptoms. Untreated HIV infection leads to AIDS (opportunistic infections and tumors) about 10 years after the initial infection.

1,100,000 (US); 36,700,000 (Global)
AIDS; HIV infection; Human immunodeficiency virus infection;
Median 10 days for symptoms; Antigen/antibody assay becomes detectable about 2-3 weeks after infection; 99% of patients have reactive assays within 6 weeks of infection; In rare cases, it may take up to 6 months to develop antibodies to HIV; [CDC Travel]
Acute infection lasting 1-2 weeks: mononucleosis-like syndrome (fever, pharyngitis, lymphadenopathy, headache, and fatigue) within a few weeks after infection; [CCDM]
"Post-exposure chemoprophylaxis for some blood exposures. [CDC 2007 Guideline for Isolation Precautions] Communicable after onset of infection and throughout life whether on treatment or not; "Sexual and needle sharing partners should not donate blood, plasma, organs, tissue, cells, or breast milk." [CCDM, p. 290-4] Call Post-Exposure Prophylaxis Hotline (PEPline) for "expert consultation about the management of health care workers with potential HIV exposure" at 1-888-448-4911. [Cecil, p. 2255] See "Standard precautions in health care" on WHO website.
The two phases of HIV infection are primary and chronic. The chronic phase has an asymptomatic period followed by a symptomatic period. About 1/2 to 2/3 of patients experience an acute HIV syndrome 1-6 weeks (usually about 3 weeks) after exposure. The illness usually lasts about 10-15 days. Common findings are fever, sweats, lymphadenopathy, sore throat, rash, myalgia, arthralgia, thrombocytopenia, leukopenia, diarrhea, and headache. Less common symptoms are nausea/vomiting, elevated liver enzymes, hepatosplenomegaly, and thrush. About 6% of patients with acute HIV syndrome have neuropathy and encephalopathy. The rash resembles measles, roseola, or urticaria and may affect the palms and soles.

Patients with chronic infection are monitored with laboratory tests: HIV RNA assay measures the viral load; CD4 count measures the risk for opportunistic infections. The average length of the asymptomatic period is about 10 years. AIDS is defined by a CD4 count of less than 200 and an immunocompromised state in which the patient is susceptible to many cancers and infections. Possible indicators of AIDS include generalized adenopathy, chronic diarrhea, generalized herpes simplex, chronic candidiasis, and unexplained weight loss, fever, or dementia.

Bacillary angiomatosis
Candida esophagitis
Cervical cancer, invasive
Coccidioidomycosis, disseminated or extrapulmonary
Cryptococcosis, extrapulmonary
Cryptosporidiosis, chronic intestinal
Cytomegalovirus disease (other than liver, spleen, or nodes)
Encephalopathy, HIV-related
Hairy leukoplakia, oral
Herpes simplex, chronic ulcers; or bronchitis, pneumonia, or esophagitis
Herpes zoster (shingles) with >2 episodes or >1 dermatome
Histoplasmosis, disseminated or extrapulmonary
HIV nephropathy
Isosporiasis, chronic intestinal
Kaposi sarcoma
Lymphoma, Burkitt's
Lymphoma, primary, of brain
Mycobacterium avium complex or M. kansasii, disseminated or extrapulmonary
Pneumocystis jiroveci pneumonia
Pneumonia, recurrent
Progressive multifocal leukoencephalopathy
Salmonella septicemia, recurrent
Toxoplasmosis of brain
Wasting syndrome due to HIV

Acquired immunodeficiency syndrome (AIDS) is a sexually transmitted disease and a global epidemic that began in the closing two decades of the twentieth century. From 2000-2020, a projected 68 million people will die prematurely from this disease. Seventy percent of HIV-positive persons live in Sub-Saharan Africa, and 2.4 million Africans died of AIDS in 2002. Without medical care and antiretroviral medications, the survival time of AIDS patients in Africa is often less than one year. Infection is transmitted mainly by sexual contact or contact with contaminated blood or needles. In the USA about 50% of infections are transmitted by men who have sex with men. In other parts of the world, most infections are transmitted by needles used to inject mood-altering drugs (Eastern Europe and central Asia) or by heterosexual intercourse (Africa). In some parts of Africa, HIV prevalence rates exceed 90% in sex workers and 50% in STD clinic patients. Anal intercourse and the presence of concurrent ulcerative STDs facilitate HIV transmission. Children are infected from their HIV-positive mothers during pregnancy, delivery, and breast feeding. The risk of occupational infection after exposure to infected blood from needle injuries is less than 0.5% for HIV compared to about 25% for hepatitis B. Worldwide, new HIV infections decreased from an estimated 3.2 million in 2001 to 2.1 million in 2013. Most HIV carriers are asymptomatic and unaware of the risk to their partners and children. [PPID, p. 1583-1707; CCDM, p. 287-94; ID, p. 163, 2363; Merck Manual, p. 1627-44; Guerrant, p. 541; Cohen, p. 879-87] "The continuing rise in the population of people living with HIV infection reflects the combined effects of continued high rates of HIV transmission and the beneficial impact of antiretroviral therapy resulting in fewer deaths. . . . Specifically regarding HIV treatment access, in 2016, an estimated 19.5 million people were on treatment, a 35-fold increase since 2005." [Cecil, p. 2170]
"Acute HIV: use 4th generation (Ag/Ab) and/or HIV RNA (viral load [VL]). Note: VL positive ~5 days before 4th generation assay, ~ 10d after acquiring infection. If high suspicion and negative 4th generation assay, check VL." [ABX Guide]
  • >arthralgia
  • >fatigue, weakness
  • >fever
  • >fever, biphasic or relapsing
  • >myalgia
  • E dysphagia
  • E epistaxis
  • E nasal ulcers
  • E pharyngitis
  • E rhinitis
  • E stomatitis
  • G abdominal mass
  • G abdominal pain
  • G blood in stool
  • G constipation
  • G diarrhea
  • G fecal leukocytes
  • G hepatomegaly
  • G jaundice
  • G liver function test, abnormal
  • G nausea, vomiting
  • H anemia
  • H eosinophilia
  • H hemolysis
  • H hypergammaglobulinemia
  • H leukocytosis
  • H leukopenia
  • H lymphadenopathy
  • H splenomegaly
  • H thrombocytopenia
  • N confusion, delirium
  • N headache
  • N lethargy
  • N muscle weakness
  • N paresthesia
  • N seizure
  • N stiff neck
  • O conjunctivitis, acute
  • O oculoglandular syndrome
  • R chest pain
  • R cough
  • R dyspnea
  • R hemoptysis
  • R sputum production
  • R wheezing
  • S cellulitis or rash, circinate
  • S entry wound with lymph nodes
  • S lymphadenitis, acute
  • S lymphangitis
  • S nodular lymphangitis
  • S papules or plaques
  • S petechiae and ecchymoses
  • S pustule
  • S rash (exanthem)
  • S rash on palms
  • S skin blister or vesicles
  • S skin or subcutaneous nodule
  • S ulcer of skin
  • S urticaria
  • S warty growth of the skin
  • S skin lesion, linear or serpiginous
  • U hematuria
  • U pyuria
  • X cystic or cavitary lesions
  • X hilar lymphadenopathy
  • X lung infiltrates
  • X pleural effusions
  • *acute renal failure
  • *ARDS
  • *arthritis
  • *bleeding tendency
  • *blindness
  • *bowel obstruction
  • *brain abscess or lesion
  • *cancer
  • *cranial neuropathy
  • *encephalitis
  • *endocarditis
  • *epididymo-orchitis
  • *erythema nodosum
  • *glomerulonephritis
  • *hepatitis
  • *mediastinitis
  • *meningitis
  • *myelitis
  • *myocarditis
  • *osteomyelitis
  • *pancreatitis
  • *paralysis
  • *pericarditis
  • *peripheral neuropathy
  • *pneumonia
  • *pneumonitis
  • *rhabdomyolysis
  • *sepsis
  • *shock
  • *stupor, coma
  • *uveitis
  • *weight loss




Needle (Includes Drug Abuse), Scalpel or Transfusion, Skin or Mucous Membranes (Includes Conjunctiva), Sexual Contact
  • Care for patients (bloodborne pathogen)
  • Handle needles or surgical instruments
  • Have a blood transfusion
  • Injection drug users
  • Travel to endemic area
  • Work in a medical or research lab
1. (US) "At the end of 2016, an estimated 1.1 million people aged 13 and older had HIV in the United States,a including an estimated 162,500 (14%) people whose infections had not been diagnosed." [CDC: HIV Surveillance Report]
2. (Global) 35.3 million cases in 2012; 36 million died so far; 1/20 are infected in sub-Saharan Africa; [Fact sheets from WHO 2013] 36.7 million people living with HIV in June 2017; [CDC Travel]