A 6-month-old girl is seen by her pediatrician for because her mother is concerned about a white coating on the infant’s tongue and poor feeding. On exam, the child appears cachectic and has thrush visible throughout her oropharynx (Figure 182-1). Palpable cervical and axillary lymph nodes are noted as well. A human immunodeficiency virus (HIV) antibody test is obtained and is positive. Diagnosis is confirmed with a HIV DNA polymerase chain reaction (PCR). The mother of the baby also tests positive for HIV. The child is treated with antiretroviral (ARV) therapy and improves with treatment.

A 15-year-old male presents to a community clinic with penile discharge and anal itching due to anal warts (Figure 182-2). On further questioning, he admits to being homeless. He supports himself through commercial sex work, mainly with male partners. A urine nucleic acid test is positive for chlamydia and the oral rapid HIV antibody test is positive as well. Diagnosis of HIV is confirmed via Western Blot testing.

HIV is a retrovirus that causes disseminated infection resulting in suppression of T-cell mediated immunity and development of opportunistic infections.

Acquired Immunodeficiency Syndrome (AIDS) refers to clinical syndrome seen with advanced disease.¹

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  Humans are the only known reservoir for HIV-1 and HIV-2.

  
  
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  HIV lives in peripheral blood mononuclear cells, brain cells, bone marrow, and genital tract cells.

  
  
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  Transmission occurs via sexual contact, blood exposure, mucous membrane exposure to blood or breast milk, and mother to child transmission.²

  
  
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  Risk of mother to child transmission at birth without intervention is approximately 30 percent;² with current therapy this risk is now 1 to 2 percent in the US. High maternal HIV viral load at delivery, primary maternal infection during pregnancy, and breast feeding all increase transmission risk.³

  
  
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  Risk of sexual transmission varies from 0.1 to 30 percent per encounter with highest risk from receptive anal sex.⁴

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  Lentivirus of the family Retroviridae.

  
  
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  Two forms—HIV-1 and HIV-2. HIV-2 causes a milder form of disease and is found predominantly in West Africa.

  
  
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  RNA virus that requires conversion of viral RNA to DNA to incorporate into host cell genome.²

  
  
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  Major enzymes and regulatory genes required for replication, assembly, and release viral particles are encoded in the viral genome including Reverse Transcriptase, Integrase, and Protease enzymes (Figure 182-3). See Diagram.

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  Unprotected sexual intercourse particularly receptive anal sex, genital ulcers or concomitant sexually transmitted diseases, intravenous drug use, maternal HIV, contaminated blood transfusion, and rarely needle stick injury.²

Clinical Features

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  Fevers, generalized lymphadenopathy, hepatosplenomegaly, failure to thrive, recurrent oral thrush, persistent diarrhea, interstitial pneumonia, invasive bacterial infection, and/or other opportunistic infection (OI).²

  
  
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  OIs include respiratory or esophageal candidiasis, cryptococcosis (Figure 182-4), disseminated endemic fungal infection, cytomegalovirus (Figure 182-5), chronic herpes simplex (Figure 182-6), progressive multifocal leukoencephalopathy caused by JC virus (Figure 182-7), Kaposi’s sarcoma caused by HHV 8 (Figure 182-8), Mycobacterium avium-intracellulare, other mycobacterial disease, cryptosporidium, Pneumocystic jirovecii (Figure 182-9), and toxoplasmosis.⁵

  
  
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  Children may also present with more severe presentations of common childhood infections (Figures 182-10 and 182-11).

  
  
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  Cervical lymphadenopathy not resolving should prompt the clinician to check for generalized lymphadenopathy and to consider HIV on the differential diagnosis (Figure 182-12).