Chapter 13: Human Immunodeficiency Virus Infection

HUMAN IMMUNODEFICIENCY VIRUS INFECTION

Human Immunodeficiency virus (HIV) may lead to acquired immunodeficiency syndrome (AIDS). Progression to AIDS is associated with opportunistic infections, cancers, and death. Advances in antiretroviral treatments (ARTs) have transformed HIV infection into a chronic illness with near normal life expectancy for those with access and adherence to lifelong therapy. See Table 13-1 for currently approved antiretroviral drugs.

Epidemiology in the United States

• Mother-to-child transmission (MTCT): In the United States, advances in HIV testing, combination ART (cART) use in pregnant HIV-infected women consisting of a minimum of three drugs from at least two different classes of antiretroviral agents, and postexposure prophylaxis of HIV-exposed infants have reduced MTCT to less than 1%. In 2017 in the United States, 73 infants were perinatally infected with HIV.

• Pediatric infection: There are about 2200 children under the age of 13 years with HIV infection in the United States. While this number has been decreasing, there is now a growing number of foreign-born HIV-infected children living in the United States.

• Adolescent and young adult infection:

  • ✓ Perinatally acquired infection: With marked improvement in the safety and efficacy of antiviral therapies, perinatally infected children usually into adulthood. However, most HIV-infected young adults have non–perinatally acquired HIV.

  • ✓ Non–perinatally acquired infection: The Centers for Disease Control and Prevention (CDC) classifies modes of transmission as: male-to-male sexual contact (men who have sex with men [MSM]); injection drug use (IDU); MSM and IDU; heterosexual contact; or other. The incidence of HIV infection has remained stable or decreased, with MSM still representing the largest risk group. African Americans and Hispanics remain disproportionately affected by HIV.

    • 44% of adolescents and young adults who tested positive for HIV were previously unaware of their diagnosis.

Differential Diagnosis

• Infancy and childhood:

  • ✓ Congenital immunodeficiencies; congenital infections; infections, such as Mycobacterium tuberculosis; malignancies; malnutrition; or other causes of failure to thrive, such as inflammatory bowel disease, celiac disease, or cystic fibrosis

• Adolescents and young adults:

  • ✓ Acute infection: Any viral syndrome such as influenza, mononucleosis (EBV, CMV); primary HSV; bacterial or viral meningitis; arbovirus or rickettsial infections; gastrointestinal infections; malignancy; rheumatologic disease and primary or secondary syphilis

  • ✓ Advanced infection: Differential diagnosis ...