Human Immunodeficiency Virus (HIV) Infection in Children and Adolescents

HIV is most commonly transmitted to children by

• An infected mother before birth or during birth

• After birth through breastfeeding

In infants, HIV infection is nearly always acquired from the mother. More than 95% of children infected with HIV in the United States acquired the infection from their mother, either before or around the time of birth (called vertical transmission or mother-to-child transmission). Most of the remaining children and adolescents now living with HIV infection acquired the infection from sexual activity, including, rarely, sexual abuse.

Because of improved safety measures regarding screening of blood and blood products, in recent years almost no infections have resulted from the use of blood and blood products in the United States, Canada, or Western Europe.

Experts are not sure how many women infected with HIV give birth each year in the United States, but the Centers for Disease Control and Prevention (CDC) estimate is about 3,000 to 5,000. Without ART, 25 to 33% of them would transmit the infection to their baby. Transmission often takes place during labor and delivery.

The risk of transmission is highest among mothers who

• Acquire HIV infection during pregnancy or while breastfeeding

• Are severely ill due to HIV infection

• Have more virus in their body

However, transmission has declined significantly in the United States from about 25% in 1991 to less than or equal to 1% in 2019. Mother-to-child transmission has been reduced because of an intensive effort to test and treat infected pregnant women during both pregnancy and delivery.

The virus also can be transmitted in breast milk. About 12 to 14% of infants who were not infected at birth acquire HIV infection if they breastfeed from a mother infected with HIV. Most often, transmission occurs in the first few weeks or months of life but may occur later. Transmission by breastfeeding is more likely in mothers who have a high level of virus in their body, including those who acquired the infection during the time period in which they were breastfeeding their infant.

In adolescents, the ways HIV infection is transmitted are the same as in adults:

• Having unprotected sexual contact

• Sharing infected needles

All adolescents are at increased risk of HIV infection if they have unprotected sex. Adolescents who share infected needles while injecting drugs are also at increased risk.

In very rare cases, HIV has been transmitted by contact with infected blood on the skin. In almost all such cases, the skin surface was broken by scrapes or open sores. Although saliva may contain the virus, there are no known cases of transmission of infection by coughing, kissing, or biting.

HIV is NOT transmitted through

• Food

• Water

• Touching the same household items (for example, clothing, furniture, and doorknobs)

• Social contact in a home, workplace, or school

Most children with HIV infection in the United States and in other high-income countries receive antiretroviral therapy. However, if children do not receive treatment, common symptoms of HIV infection include

• Slowed growth and a delay of maturation

• Enlargement of lymph nodes in several areas of the body

• Repeated episodes of bacterial infections

• Recurring diarrhea

• Lung infections

• Enlargement of the spleen or liver

• Fungal infection of the mouth (thrush)

• Anemia

• Heart problems

• Hepatitis

• Opportunistic infections

Sometimes children who are not receiving treatment have repeated episodes of bacterial infections, such as a middle ear infection (otitis media), sinusitis, bacteria in the blood (bacteremia), or pneumonia. About one third of children with untreated HIV infection develop lung inflammation (lymphoid interstitial pneumonitis), with cough and difficulty breathing. A variety of other symptoms and complications can appear as the child's immune system deteriorates.

If infants or young children who become infected with HIV infection develop severe illness, called AIDS, they commonly have at least one episode of Pneumocystis jirovecii pneumonia (see Pneumonia in Immunocompromised People). This serious opportunistic infection can occur as early as 4 to 6 weeks of age but occurs mostly in infants 3 to 6 months of age who acquired HIV infection before or at birth. More than half of untreated children infected with HIV develop the pneumonia at some time. Pneumocystis pneumonia is a major cause of death among children and adults with AIDS.

In a significant number of untreated children with HIV infection, progressive brain damage prevents or delays developmental milestones, such as walking and talking. These children also may have impaired intelligence and a head that is small in relation to their body size. Up to 20% of untreated infected children progressively lose social and language skills and muscle control. They may become partially paralyzed or unsteady on their feet, or their muscles may become somewhat rigid.

Anemia (a low red blood cell count) is common if HIV infection is not treated and causes children to become weak and tire easily. About 20% of untreated children develop heart problems, such as rapid or irregular heartbeat, or heart failure.

Untreated children also commonly develop inflammation of the liver (hepatitis) or inflammation of the kidneys (nephritis). Cancers are uncommon in children with AIDS, but non-Hodgkin lymphoma and lymphomas of the brain may occur somewhat more often than in uninfected children. Kaposi sarcoma, an AIDS-related cancer that affects the skin and internal organs, is common among adults infected with HIV but is very rare in children infected with HIV.

ART has significantly changed the way HIV infection manifests in children. ART is very effective and allows HIV infection to be managed as a chronic disease. With ART, children with HIV infection usually do not develop any symptoms of HIV infection. Although bacterial pneumonia and other bacterial infections (such as bacteremia and recurring otitis media) occur slightly more often in children with HIV infection, opportunistic infections and growth failure are rare.

Although ART clearly lessens the effects of brain and spinal cord disorders, there seems to be an increased rate of behavioral, developmental, and cognitive problems in treated children infected with HIV. It is unclear whether these problems are caused by HIV infection itself, the medications used to treat HIV, or other biologic, psychologic, and social factors that are common among children with HIV infection.

Because ART has allowed children and adults to survive for many years, more people are developing long-term complications of HIV infection. These complications include obesity, heart disease, diabetes, and kidney disease. These complications appear to be related both to HIV infection itself and to the effects of certain ART medications.

The symptoms of HIV infection acquired during adolescence are similar to those in adults (see symptoms of HIV infection in adults).

The diagnosis of HIV infection in children begins with the identification of HIV infection in pregnant women through routine prenatal screening of blood. Women should be tested for HIV infection early in pregnancy and again in the third trimester to detect newly acquired HIV infection.

Rapid tests for HIV using blood or saliva can be done while women are in labor and delivery units at the hospital. These tests can provide results in minutes to hours.

For all children under 18 months of age, standard adult blood tests for HIV antibodies or antigens are not helpful, because the blood of an infant born to an mother with HIV infection almost always contains HIV antibodies passed through the placenta even if the infant is not infected.

So, to definitively diagnose HIV infection in children under 18 months of age, special blood tests called nucleic acid tests (NATs) are done. The diagnosis of HIV infection is confirmed if the NATs detect genetic material from HIV (DNA or RNA) in the child's blood.

Testing using NATs should be done at frequent intervals, typically in the first 2 weeks of life, at about 1 month of age, and between 4 months and 6 months of age. Such frequent testing identifies most infants infected with HIV by 6 months of age. Some infants who have a very high risk of developing HIV may be tested more frequently.

All children in this age group should be tested if they are born to mothers who

• Have HIV infection

• Are at risk of HIV infection

For children older than 18 months and adolescents, the same blood tests offered for diagnosis of HIV infection in adults may be used. These are usually blood tests that are done to look for HIV antibodies and antigens. (Antibodies are proteins produced by the immune system to help defend the body against attack, and antigens are substances that can trigger an immune response in the body—see Tests That Detect Antibodies to or Antigens of Microorganisms.)

Once HIV infection has been diagnosed, doctors regularly do blood tests at 3- to 4-month intervals to monitor the number of CD4+ lymphocytes (CD4 count) and the number of virus particles in the blood (viral load).

Lymphocytes are a type of white blood cell. The number of CD4+ lymphocytes decreases as HIV infection worsens. If the CD4 count is low, children are more likely to develop serious infections and other complications of HIV, such as certain cancers.

The viral load increases as HIV infection worsens. Viral load helps predict how fast the CD4 count is likely to decrease over the next few years.

The CD4 count and viral load help doctors determine how soon to start antiretroviral medications, what effects treatment is likely to have, and whether other medications may be needed to prevent complicating infections.

All children with HIV infection should be given antiretroviral therapy (ART) as soon as possible, ideally within 1 to 2 weeks of diagnosis. Children are treated with most of the same antiretroviral medications as adults (see Drug Treatment of Human Immunodeficiency Virus (HIV) Infection). However, not all of the medications used for older children, adolescents, and adults are available to young children, in part because some are not available in liquid form.

ART is tailored to the child, but combinations typically consist of the following:

• Two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) plus either

• An integrase inhibitor or a protease inhibitor

Sometimes a non-nucleoside reverse transcriptase inhibitor is given with two NRTIs.

In general, children develop the same types of side effects as adults but usually at a much lower rate. However, the side effects of medications may also limit the treatment.

A doctor monitors the effectiveness of treatment by regularly measuring the amount of virus present in the blood (viral load) and the child's CD4+ cell count (see diagnosis of HIV infection in children). Doctors routinely do several other tests, and give adolescent girls a pregnancy test.

Increased numbers of virus in the blood may be a sign that the virus is developing resistance to the medications or that the child is not taking the medications. In either case, the doctor may need to change the medications. To monitor a child's progress, the doctor examines the child and does blood tests on the child at 3- to 4-month intervals. Other blood tests and urine tests are done at 6- to 12-month intervals.

Lab Test

HIV Viral Load

Adherence is taking medications as directed. Adhering to prescribed ART dosing schedules is extremely important. If children take ART medications less often than they are supposed to, the HIV in their system can rapidly become permanently resistant to one or more of the medications. Yet, it may be difficult for parents and children to follow and adhere to complicated medication regimens, which can limit the effectiveness of therapy. To simplify regimens and improve adherence, tablets containing three or more medications may be given. These tablets may need to be taken only once or twice a day. The liquid forms of medications are now better-tasting, which improves adherence.

Adherence to ART may be more difficult for adolescents than for younger children. Adolescents also have difficulty adhering to treatment regimens for other chronic diseases such as diabetes and asthma (see also Chronic Health Problems in Children). Adolescents want to be like their peers and can feel set apart by their illness. Skipping or stopping treatment may be a way for them to deny having an illness. Additional issues that may complicate treatment and reduce adherence in adolescents include

• Low self-esteem

• A chaotic and unstructured lifestyle

• Fear of being singled out because of illness

• Sometimes a lack of family support

In addition, adolescents may not be able to understand why medications are necessary when they do not feel ill and they may worry greatly about side effects.

Despite frequent contact with a pediatric health care team, adolescents who have been infected since birth may fear or deny their HIV infection or distrust information provided by the health care team. Instead of directly confronting adolescents who have poor support systems about the need to take their medications, care teams sometimes help the adolescent focus on practical matters such as how to avoid opportunistic infections and how to obtain information about reproductive health services, housing, and succeeding in school (see Transition to Adult Care).

To prevent Pneumocystis pneumoniaCD4 count is. All infants who were born to women infected with HIV are given trimethoprim/sulfamethoxazole beginning at 4 to 6 weeks of age until testing shows they are not infected. Children who cannot tolerate trimethoprim/sulfamethoxazole

Mycobacterium avium complex infection, depending on their age and CD4 count

Nearly all children infected with HIV should receive the routine childhood vaccinations, including

• Diphtheria, tetanus, and pertussis (DTaP)

• Inactivated polio vaccine

• Influenza (inactivated, not live vaccine)

• Haemophilus influenzae

• Streptococcus pneumoniae

• Hepatitis A and hepatitis B

• Rotavirus vaccine

• Meningococcal conjugate vaccine

• Pneumococcal vaccine

• COVID-19

Yearly inactivated or live influenza immunization is also recommended for household members.

Some vaccines containing live bacteria, such as bacille Calmette-Guérin (which is used to prevent tuberculosis in some countries outside the United States), or live viruses, such as the oral polio virus (not available in the United States but still used in other parts of the world), varicella, and measles-mumps-rubella, can cause a severe or fatal illness in children with HIV whose immune system is very impaired. However, the live measles-mumps-rubella vaccine, live varicella vaccine, and, in some areas of the world, live yellow fever vaccine and live dengue virus vaccine are recommended for children with HIV infection whose immune system is not severely impaired.

However, the effectiveness of any vaccination is less in children with HIV infection. Children infected with HIV who have very low CD4+ cell counts are considered susceptible to vaccine-preventable diseases when they are exposed to one (such as measles, tetanus, or varicella) regardless of whether they have received the vaccine for that disease and may be given immune globulin by vein (intravenously). Intravenous immune globulin or immediate vaccination with measles-mumps-rubella vaccine also should be considered for any nonimmunized household member who is exposed to measles.

For children in child care or school, or if a child needs foster care, a doctor can help assess the child's risk of exposure to infectious diseases. In general, transmission of infections, such as chickenpox, to children with HIV infection (or to any child with an impaired immune system) is more of a danger than is transmission of HIV from that child to others. However, a young child with HIV infection who has open skin sores or who engages in potentially dangerous behavior, such as biting, should not attend child care.

Children with HIV infection should participate in as many routine childhood activities as their physical condition allows. Interaction with other children enhances social development and self-esteem. Because of the stigma associated with the illness, the routine use of universal precautions in schools and day care centers, and the fact that transmission of the infection to other children is extremely unlikely, there is no need for anyone other than the parents, the doctor, and perhaps the school nurse to be aware of the child's HIV status.

As a child's condition worsens, treatment is best given in the least restrictive environment possible. If home health care and social services are available, the child can spend more time at home rather than in a hospital.

Current preventive therapy for infected pregnant women is highly effective at minimizing transmission. Pregnant women with HIV infection should begin antiretroviral therapy (ART) by mouth. Ideally, ART should begin as soon as HIV infection is diagnosed and women are ready to follow the therapy as directed. Pregnant women with HIV infection who are already on ART should continue the therapy throughout the pregnancy. Women with HIV infection should also continue ART when trying to get pregnant.

cesarean delivery (c-section) done before labor begins may reduce the newborn's risk of acquiring HIV infection. Doctors may recommend cesarean delivery for women whose infection is not well controlled by ART. After delivery, ART is continued for all women with HIV infection.

Because HIV can be transmitted during breastfeeding and in breast milk, the decision to breastfeed should be made only after counseling and decision-making discussions with health care practitioners.

In countries where the risks of undernutrition and infection resulting from unclean water or formula are high and safe, affordable infant formula is not available, the benefits of breastfeeding may outweigh the risk of HIV transmission. In these countries, mothers with HIV infection under medical supervision may continue to breastfeed for at least 12 months of the infant's life and then rapidly wean the infant to food. Often their infants are given ART throughout the period of breastfeeding.

Mothers with HIV infection should be advised never to donate their breast milk to milk banks.

Mothers with HIV infection should not prechew (premasticate) food for infants.

Because a child's HIV status may not be known, all schools and day care centers should adopt special procedures for handling accidents, such as nosebleeds, and for cleaning and disinfecting surfaces contaminated with blood.

During cleanup, personnel are advised to avoid having their skin come in contact with blood. Latex gloves should be routinely available, and hands should be washed after the gloves are removed.

Contaminated surfaces should be cleaned and disinfected with a freshly prepared bleach solution containing 1 part of household bleach to 10 to 100 parts of water.

These practices are called universal precautions and are followed not only for children with HIV infection but for all children and in all situations involving blood.

Prevention for adolescents is the same as prevention for adults. All adolescents should have access to HIV testing and should be taught how HIV is transmitted and how it can be avoided, including abstaining from high-risk behaviors (such as sharing infected needles) and sex or using safe-sex practices.

Taking an antiretroviral medication before being exposed to HIV can reduce the risk of HIV infection. Such preventive treatment is called pre-exposure prophylaxis (PrEP).

PrEP is most effective if people take the medication every day, but it can be expensive, so PrEP is recommended most often for people who are not infected with HIV but who have a high risk of becoming infected, such as people who have a sex partner who is infected with HIV, men who have sex with men, and people who are transgender. Older adolescents at risk may also receive PrEP, but issues of confidentiality and cost are more complex than with adult PrEP.

People who use PrEP still need to use other methods to prevent other infections, including consistent use of condoms and not sharing needles to inject drugs.