++
Human immunodeficiency virus (HIV) has led to a worldwide pandemic that has exacted a dramatic toll on children, especially in resource-limited countries. It is estimated that approximately 1.8 million children younger than 15 years of age were living with HIV in 2015, the vast majority in sub-Saharan Africa.1 In the same year worldwide, approximately 150,000 children were infected perinatally with HIV and 110,000 children died due to HIV/AIDS (acquired immunodeficiency syndrome).1 In 2014 in the United States there were approximately 9000 children and youth less than 19 years of age living with diagnosed HIV infection.2 In resource-rich countries including the United States, the vertical transmission rate has dropped to less than 2%,3-6 and combination antiretroviral therapy (ART) has diminished mortality and morbidity associated with HIV disease.7-9 The pediatric hospitalist must be familiar with the care of HIV-exposed newborns and HIV-infected children, because the initial diagnosis and management of complications often occur in the hospital setting.
++
Historically, HIV infection and AIDS were differentiated by the 1987 Centers for Disease Control (CDC) case definition for AIDS surveillance—that is, the presence of opportunistic infections or other so-called AIDS-defining conditions.10 The pediatric classification of the severity of HIV disease was subsequently revised to include infection status, clinical status, and immunologic status (Tables 108-1 and 108-2).11,12 The absolute CD4+ T-cell count and CD4% decline naturally with age until 6 years of age when they stabilize at adult levels (Table 108-2). Thus, a 4 year old HIV-infected child with a prior episode of Pneumocystis jiroveci pneumonia (previously Pneumocystis carinii pneumonia, abbreviated PJP) and a prior CD4 count nadir of 350 cells/mm2 would be categorized as C3.12
++++