Version May 2024
INTRODUCTION — Considerable progress has been made towards eliminating human immunodeficiency virus (HIV) among children; however, the global burden of pediatric HIV and acquired immune deficiency syndrome (AIDS) remains a challenge for health care workers around the world, particularly in resource-limited countries.
The epidemiology of HIV infection in children will be discussed here. The case definition, clinical manifestations, and outcomes of pediatric HIV; prophylactic treatment of infants born to HIV-infected mothers; diagnostic testing for HIV in young children; and issues related to HIV infection in adolescents are discussed separately:
●(See "Pediatric HIV infection: Classification, clinical manifestations, and outcome".)
●(See "Diagnostic testing for HIV infection in infants and children younger than 18 months".)
●(See "The adolescent with HIV infection".)
GLOBAL HIV/AIDS STATISTICS — Significant progress is being made in the quest to eliminate HIV among children. In 2020, 150 children <15 years old were newly infected with HIV, bringing the total number of children worldwide living with HIV or AIDS to 1.7 million [1]. Most reside in resource-limited areas, with approximately 90 percent living in sub-Saharan Africa. Most HIV infections in children are acquired via mother-to-child transmission (MTCT) during pregnancy, labor, delivery, or breastfeeding. Therefore, the epidemiology of pediatric HIV is inextricably related to the success of prevention of MTCT efforts.
Resource-rich countries — In the United States and other resource-rich countries, the number of children younger than 13 years of age newly diagnosed with HIV has decreased dramatically due to successful MTCT prevention interventions. The Centers for Disease Control and Prevention (CDC) estimates that the number of children diagnosed with perinatally acquired HIV in the United States dropped from a peak of 1650 in 1991 to 65 in 2018 [2]. In the United States, MTCT prevention efforts began as early as 1985 with the recommendation for HIV testing in high-risk pregnant women and the avoidance of breastfeeding in HIV-infected women. In 2012, the CDC presented a framework for the elimination of HIV MTCT [3]. The framework includes the following interventions:
●Prevention of HIV infection in women and girls of childbearing potential
●Identification of HIV infection among women and girls of childbearing potential
●Assurance of adequate preconception antiretroviral therapy (ART) and family planning services for women living with HIV infection
●Early identification of HIV infection of pregnant women through universal prenatal screening
●Provision of adequate prenatal care for women living with HIV infection
●Maximal reduction of maternal viral load through appropriate use of ART
●Cesarean delivery when maternal viral load is not maximally suppressed
●Provision of neonatal antiretroviral (ARV) prophylaxis
●Neonatal replacement feeding as well as maternal support for lactation suppression
Prenatal and intrapartum management of HIV-infected women is discussed in detail separately. (See "Prenatal evaluation of women with HIV in resource-rich settings".)
In the United States, when HIV-infected women and their infants receive all applicable MTCT prevention interventions, MTCT rates can be reduced to approximately 1 percent [4]. Transmission rates in the United Kingdom and Ireland have similarly declined to <0.5 percent, with only nine known incidents of MTCT in women known to be HIV infected prior to delivery in the years 2010 to 2011 [5].
In the United States and other resource-rich countries, outcomes for HIV-infected children have improved, in large part due to use of powerful combinations of ARV drugs. (See "Pediatric HIV infection: Classification, clinical manifestations, and outcome", section on 'HIV infection treated with antiretroviral therapy'.)
Resource-limited countries — In 2019, approximately 150,000 infants and children aged zero to nine years were newly infected with HIV worldwide, bringing the total number of children living with HIV worldwide to 1.1 million [6]. Additionally, 170,000 adolescents aged 10 to 19 years were newly infected with HIV worldwide, with 130,000 (76 percent of new infections) occurring among adolescent girls, bringing the total number of adolescents living with HIV worldwide to 1.7 million [2].
Of the estimated 680,000 people who died of AIDS-related illnesses worldwide in 2020, approximately 16 percent were under the age of 20 years [6].
More than 90 percent of children living with HIV in resource-limited countries were infected through MTCT during pregnancy, perinatally, or through breastfeeding. Just as in the United States and other resource-rich countries, increasing emphasis has been placed on efforts to prevent MTCT with the use of ARV medications in pregnant women during pregnancy and at delivery and in the exposed infant starting immediately after birth. It is hoped that with continued expansion of MTCT prevention programs, vertical transmission of HIV may become rare in the future. (See "Prevention of vertical HIV transmission in resource-limited settings".)
RISK FACTORS FOR HIV ACQUISITION
Exposure through sexual contact — Sexual intercourse is the major route of transmission of HIV throughout the world. The precise risk of HIV transmission from one act of sexual intercourse with an infected person is not known. Although some people have had multiple sexual contacts with an infected person without acquiring HIV infection, others have become infected after one sexual encounter.
In general, the risk of acquiring a sexually transmitted infection is proportional to the number of different sexual partners. However, for some women, a steady male partner who has sexual contact outside the primary relationship is the only source of HIV exposure.
Several biomedical interventions have the potential for radically changing the patterns and rates of HIV transmission. Randomized controlled trials in several African countries indicate that male medical circumcision reduces the risk of heterosexually acquired HIV infection in men, and the World Health Organization (WHO) recommends male circumcision as part of a comprehensive HIV prevention package. The effect of male circumcision on HIV transmission is discussed separately. (See "Neonatal circumcision: Risks and benefits", section on 'Reduction in HIV and other sexually transmitted infections'.)
Pre-exposure prophylaxis against HIV infection is discussed separately. (See "HIV pre-exposure prophylaxis", section on 'Summary and recommendations'.)
Exposure through blood or blood products — Direct exposure to HIV-infected blood is an efficient way to transmit HIV. Exposure to HIV-infected blood may occur nosocomially through a tainted blood transfusion or through needlestick accidents suffered by health care workers, or in the community through the use of nonsterile razor blades for ritual scarring or traditional healing.
Compared with industrialized nations, countries in sub-Saharan Africa experience more transfusion-associated HIV transmission because of a higher prevalence of HIV infection in donor populations, a lack of HIV antibody screening in some areas, and a higher residual risk of contamination in blood supplies, despite antibody screening.
Exposure through injection drug use — Injection of illicit drugs is increasingly associated with transmission of HIV worldwide. (See "Global epidemiology of HIV infection", section on 'Injection drug use'.)
Exposure through pregnancy, birth, or breastfeeding — Vertical transmission of HIV can occur at any time during gestation and delivery and through breast milk in the postpartum period. More than 90 percent of HIV-infected children worldwide have acquired the virus via vertical transmission. In the absence of antiretroviral (ARV) therapy, the rate of vertical transmission of HIV is approximately 25 percent [7]. The use of ARV therapy in HIV-infected pregnant women and their infants has dramatically reduced mother-to-child transmission (MTCT). Although it is known that HIV can be transmitted early in gestation in utero, most transmissions (50 to 80 percent) are believed to occur during the time period near or during delivery [8]. (See "Prevention of vertical HIV transmission in resource-limited settings", section on 'Risk of vertical HIV transmission' and "Antiretroviral selection and management in pregnant individuals with HIV in resource-rich settings".)
Risk factors for HIV transmission through breastfeeding are discussed separately. (See "Prevention of HIV transmission during breastfeeding in resource-limited settings", section on 'Epidemiology of HIV transmission through breastfeeding'.)
PROGRESS IN PROVIDING PEDIATRIC TREATMENT — Continued emphasis on prevention of new pediatric infections through programs aimed at preventing mother-to-child transmission (MTCT) and expanding care and treatment services for HIV-infected children is critical.
Globally, there are a number of barriers to implementing pediatric antiretroviral (ARV) therapy on a wide scale. These include:
●Lack of infrastructure
●Lack and loss of health professional capacity
●The relatively high cost of some pediatric formulations of ARV medications
●The perceived complexity of treating children
The Joint United Nations Programme on HIV/AIDS (UNAIDS) estimates that in 2018, only approximately 85 percent of pregnant women living with HIV had access to antiretroviral therapy (ART) [9]. This falls short of the target of reaching 95 percent of pregnant women by 2018. However, it nonetheless reflects ongoing improvement in access to ARV (up from 77 percent in 2015, 57 percent in 2011, 45 percent in 2008, and 15 percent in 2005).
UNAIDS estimates that of the 1.7 million children <15 years old living with HIV in 2018, only 54 percent received ARV therapy. While this is a substantial increase from their report in 2009, at which time only 15 percent of children living with HIV received ARV therapy, it means that in 2018, 46 percent of children who needed treatment were still not accessing it. This gap must be addressed urgently since without treatment, approximately one-half of HIV-infected infants die by the age of two years and approximately 100,000 children <15 years old die from HIV and AIDS each year [9,10].
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: HIV infection in infants and children".)
SUMMARY
●In the United States and other resource-rich countries, the incidence of HIV has decreased as a consequence of successful programs to prevent vertical transmission of HIV, including HIV counseling and testing services for pregnant women, antiretroviral (ARV) therapy, providing alternatives to breastfeeding, and educational programs. (See 'Resource-rich countries' above.)
●New cases of HIV and HIV deaths among children continue to occur in resource-limited settings, particularly sub-Saharan Africa, where access to care and treatment services for HIV and programs to prevent mother-to-child transmission (MTCT) of HIV are limited. (See 'Resource-limited countries' above.)
●More than 90 percent of HIV-infected children worldwide have acquired the virus through vertical transmission, which can be prevented by the use of ARV therapy among HIV-infected pregnant women and their infants. (See 'Exposure through pregnancy, birth, or breastfeeding' above.)
●Biomedical prevention interventions, including male circumcision and pre-exposure prophylaxis, may play a significant role in curbing the acquisition of new infections through sexual contact. (See 'Exposure through sexual contact' above and "HIV pre-exposure prophylaxis".)
●Without treatment, approximately one-half of children with vertically acquired HIV infection die by the age of two years. Continued emphasis on prevention of new pediatric infections through expansion of programs that prevent MTCT and provide treatment services for HIV-infected children is critical. (See 'Progress in providing pediatric treatment' above.)
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