HIV Infection in Children
Introduction to HIV Infection in Children
Human Immunodeficiency Virus (HIV) infection in children remains a significant global health challenge, particularly in resource-limited settings. Pediatric HIV infection differs from adult HIV in several crucial aspects, including transmission routes, disease progression, and treatment approaches.
Key points:
- Most pediatric HIV infections occur through mother-to-child transmission (MTCT).
- Without intervention, the risk of MTCT is 15-45%.
- Early diagnosis and treatment are critical for improving outcomes.
- HIV in children progresses more rapidly than in adults due to immature immune systems.
Epidemiology of Pediatric HIV
The global burden of pediatric HIV has seen significant reductions due to effective prevention and treatment programs, but challenges persist:
- As of 2021, approximately 1.7 million children under 15 were living with HIV globally.
- Sub-Saharan Africa accounts for over 90% of pediatric HIV cases.
- New infections in children have decreased by 52% since 2010 due to improved MTCT prevention.
- Access to antiretroviral therapy (ART) for children lags behind that for adults, with only about 54% of children receiving treatment globally.
Factors influencing epidemiology:
- Maternal HIV prevalence
- Access to antenatal care and HIV testing
- Availability and uptake of prevention of mother-to-child transmission (PMTCT) services
- Breastfeeding practices in HIV-positive mothers
Transmission of HIV to Children
The primary mode of HIV transmission in children is mother-to-child transmission (MTCT), also known as vertical transmission. This can occur during:
- Pregnancy (in utero): Accounts for about 5-10% of cases
- Labor and delivery (intrapartum): Responsible for 10-20% of cases
- Breastfeeding (postpartum): Can contribute to 5-20% of transmissions
Factors increasing the risk of MTCT:
- High maternal viral load
- Advanced maternal HIV disease
- Lack of antiretroviral therapy during pregnancy and breastfeeding
- Prolonged rupture of membranes during delivery
- Preterm delivery
- Invasive obstetric procedures
Other less common modes of transmission in children include:
- Blood transfusions (rare in settings with adequate blood screening)
- Sexual abuse
- Injection drug use (in adolescents)
Pathophysiology of Pediatric HIV
The pathophysiology of HIV infection in children is similar to that in adults but with some key differences:
- Immature immune system: Children's developing immune systems are more susceptible to rapid HIV progression.
- Higher viral loads: Children often maintain higher viral loads than adults, leading to faster disease progression.
- CD4 count interpretation: Normal CD4 counts are higher in children, necessitating age-specific interpretation.
- Thymus involvement: HIV infection can impair thymus function, critical for T-cell development in children.
Disease progression:
- Rapid progressors (20-30%): Develop AIDS within the first year of life without treatment.
- Intermediate progressors (50-60%): Develop AIDS by 5-7 years of age.
- Slow progressors (10-15%): May remain asymptomatic beyond 8 years.
Key pathophysiological processes:
- Persistent viral replication leading to chronic immune activation
- Progressive depletion of CD4+ T cells
- Impaired B-cell function and antibody responses
- Disruption of gut-associated lymphoid tissue (GALT)
- Increased susceptibility to opportunistic infections and malignancies
Clinical Manifestations of Pediatric HIV
The clinical presentation of HIV in children can vary widely, from asymptomatic infection to severe AIDS-defining illnesses. Common manifestations include:
- Growth failure: Failure to thrive, stunting, wasting
- Recurrent infections: Pneumonia, otitis media, sinusitis, skin infections
- Persistent or recurrent diarrhea
- Lymphadenopathy
- Hepatosplenomegaly
- Oral candidiasis
- Parotid enlargement
- Neurological manifestations: Developmental delay, encephalopathy
AIDS-defining conditions in children:
- Pneumocystis jirovecii pneumonia (PCP)
- Cryptococcal meningitis
- Toxoplasmosis
- Cytomegalovirus (CMV) disease
- Mycobacterium avium complex (MAC) infection
- HIV encephalopathy
- Kaposi's sarcoma
- Lymphoma
Age-specific considerations:
- Infants: Rapid disease progression, severe infections
- Young children: Recurrent bacterial infections, growth issues
- Older children/adolescents: Chronic symptoms, opportunistic infections
Diagnosis of HIV in Children
Early diagnosis is crucial for initiating timely treatment and improving outcomes. Diagnostic approaches differ based on the child's age:
Infants < 18 months:
- Virological tests: Preferred method
- HIV DNA PCR
- HIV RNA PCR
- Timing: First test at 4-6 weeks, confirm positive results ASAP
- Antibody tests not reliable: Due to maternal antibodies
Children ≥ 18 months:
- Antibody tests: Standard approach
- Rapid diagnostic tests (RDTs)
- Enzyme-linked immunosorbent assay (ELISA)
- Confirmation: Western blot or second antibody test
Additional diagnostic considerations:
- CD4 count and percentage: Assess immune status
- Viral load testing: For monitoring treatment response
- HIV drug resistance testing: If available, before starting ART
WHO Clinical Staging: Used in resource-limited settings to guide treatment decisions
- Stage 1: Asymptomatic or persistent generalized lymphadenopathy
- Stage 2: Moderate unexplained weight loss, recurrent respiratory infections
- Stage 3: Severe weight loss, chronic diarrhea, persistent fever
- Stage 4: Wasting syndrome, Pneumocystis pneumonia, Kaposi's sarcoma
Treatment of Pediatric HIV
The primary goal of HIV treatment in children is to suppress viral replication, preserve or restore immune function, prevent opportunistic infections, and promote normal growth and development.
Antiretroviral Therapy (ART):
- Initiation: All HIV-infected children should start ART regardless of clinical or immunological stage
- First-line regimen: Typically includes two nucleoside reverse transcriptase inhibitors (NRTIs) plus a third agent (non-nucleoside reverse transcriptase inhibitor [NNRTI] or integrase inhibitor)
- Dosing: Weight-based or surface area-based, requiring frequent adjustments as the child grows
Common ART regimens for children:
- Abacavir + Lamivudine + Dolutegravir
- Abacavir + Lamivudine + Lopinavir/ritonavir
- Zidovudine + Lamivudine + Nevirapine (in some resource-limited settings)
Monitoring:
- Regular assessment of adherence
- Viral load testing (goal: viral suppression)
- CD4 count and percentage
- Growth and development monitoring
- Screening for ART side effects and toxicities
Management of opportunistic infections:
- Cotrimoxazole prophylaxis for Pneumocystis pneumonia
- TB preventive therapy in high-burden settings
- Prompt diagnosis and treatment of intercurrent infections
Nutritional support:
- Regular nutritional assessment
- Micronutrient supplementation
- Therapeutic feeding for malnutrition
Psychosocial support:
- Disclosure counseling (age-appropriate)
- Mental health screening and support
- Family and caregiver education
Prevention of Pediatric HIV
Prevention of mother-to-child transmission (PMTCT) is the cornerstone of pediatric HIV prevention. A comprehensive approach includes:
Antenatal care:
- Universal HIV testing for pregnant women
- Initiation of ART for all HIV-positive pregnant women
- Regular viral load monitoring during pregnancy
Labor and delivery:
- Continuation of maternal ART
- Consider elective cesarean section for high viral loads
- Minimize invasive procedures during delivery
Postpartum and infant care:
- Antiretroviral prophylaxis for exposed infants
- Early infant diagnosis
- Counseling on infant feeding options
Breastfeeding recommendations:
- In resource-rich settings: Avoid breastfeeding if safe alternatives are available
- In resource-limited settings: Exclusive breastfeeding for 6 months with maternal ART
Other prevention strategies:
- Prevention of unintended pregnancies in HIV-positive women
- Partner testing and treatment
- Community education and stigma reduction
Post-exposure prophylaxis (PEP):
- For infants born to mothers with unknown HIV status
- In cases of accidental exposure (e.g., needlestick injuries)
Pre-exposure prophylaxis (PrEP):
- For adolescents at high risk of HIV acquisition
- Requires careful consideration of risks and benefits
Prognosis and Follow-up
The prognosis for children with HIV has improved dramatically with the advent of effective antiretroviral therapy (ART). However, outcomes can vary based on several factors:
Factors influencing prognosis:
- Age at diagnosis and ART initiation
- Adherence to ART
- Presence of opportunistic infections or comorbidities
- Nutritional status
- Psychosocial support and care
Long-term outcomes:
- Improved survival rates, approaching those of HIV-negative children in some settings
- Potential for normal growth and development with early ART
- Risk of neurocognitive impairment, especially if ART is delayed
- Increased risk of non-AIDS-defining conditions (e.g., cardiovascular disease, bone disorders)
Follow-up and monitoring:
- Regular clinical assessments (every 3-6 months)
- Viral load monitoring (at least annually, more frequently if concerns about adherence)
- CD4 count monitoring
- Growth and development tracking
- Screening for ART toxicities and drug interactions
- Immunization updates
- Psychosocial support and mental health screening
Transition to adult care:
- Planned transition process starting in early adolescence
- Focus on building self-management skills
- Addressing unique challenges of adolescents living with HIV
Quality of life considerations:
- Educational support and vocational training
- Reproductive health counseling
- Management of HIV disclosure to peers and partners
- Long-term psychosocial support
HIV Infection in Children
- What is HIV?
Human Immunodeficiency Virus, a retrovirus that attacks the immune system - What are the main modes of HIV transmission to children?
Mother-to-child transmission (MTCT), blood transfusions, and sexual abuse - What percentage of HIV infections in children are due to mother-to-child transmission?
Approximately 90% of pediatric HIV infections - During which stages of pregnancy can HIV be transmitted from mother to child?
In utero, during delivery, and through breastfeeding - What is the risk of HIV transmission from an untreated HIV-positive mother to her child?
15-45% without intervention - How can mother-to-child transmission of HIV be prevented?
Antiretroviral therapy for the mother, prophylaxis for the infant, and avoiding breastfeeding when safe alternatives are available - What is the recommended first-line test for diagnosing HIV in infants under 18 months?
HIV DNA PCR or HIV RNA PCR test - Why are antibody tests not reliable for diagnosing HIV in infants under 18 months?
Maternal antibodies can persist in the infant's blood, potentially causing false-positive results - What is the World Health Organization's recommendation for when to start antiretroviral therapy (ART) in HIV-infected children?
As soon as possible after diagnosis, regardless of CD4 count or clinical stage - What are the three main classes of antiretroviral drugs used in pediatric HIV treatment?
Nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs) - What is the goal of antiretroviral therapy in children?
To suppress viral replication, restore and preserve immune function, reduce HIV-related morbidity and mortality, and improve quality of life - How often should CD4 count and viral load be monitored in HIV-infected children on ART?
Every 3-6 months, or more frequently if clinically indicated - What is considered viral suppression in children on ART?
HIV RNA levels below the limit of detection of the assay used (typically <20-50 copies/mL) - What are some common opportunistic infections in HIV-infected children?
Pneumocystis pneumonia, tuberculosis, candidiasis, and cytomegalovirus infection - What is the most common cause of death in HIV-infected children worldwide?
Pneumonia, often caused by Pneumocystis jirovecii - How does HIV affect growth and development in children?
It can lead to growth failure, developmental delays, and neurocognitive impairment - What is HIV encephalopathy?
A syndrome of impaired brain growth and motor and cognitive dysfunction due to HIV infection of the central nervous system - How does HIV affect the nutritional status of infected children?
It can lead to malnutrition through decreased intake, malabsorption, and increased metabolic demands - What is lipodystrophy syndrome in HIV-infected children?
A metabolic complication characterized by fat redistribution and metabolic abnormalities, often associated with certain antiretroviral drugs - How does HIV infection impact the vaccination schedule for children?
Live vaccines may be contraindicated in severely immunocompromised children, and response to vaccines may be suboptimal - What is the role of cotrimoxazole prophylaxis in HIV-infected children?
To prevent Pneumocystis pneumonia and other opportunistic infections - At what age should HIV-infected children be disclosed their HIV status?
Gradual disclosure is recommended, starting as early as 6-7 years old, with full disclosure typically by age 12 - What is the impact of HIV on the child's immune system?
Progressive depletion of CD4+ T cells, leading to immunodeficiency and increased susceptibility to infections and malignancies - How does HIV affect the cardiovascular system in children?
It can lead to cardiomyopathy, pulmonary hypertension, and accelerated atherosclerosis - What is the risk of tuberculosis in HIV-infected children?
Significantly increased risk compared to HIV-negative children, with more severe and disseminated disease - How does HIV affect bone metabolism in children?
It can lead to decreased bone mineral density and increased risk of fractures - What is the role of resistance testing in pediatric HIV management?
To guide the selection of antiretroviral regimens, especially in cases of treatment failure - How does HIV infection impact the mental health of children?
Increased risk of depression, anxiety, and behavioral problems - What is the recommended duration of antiretroviral therapy for HIV-infected children?
Lifelong therapy is currently recommended - How does HIV affect the liver in infected children?
It can cause direct liver injury, increase susceptibility to viral hepatitis, and lead to drug-induced liver toxicity - What is the role of therapeutic drug monitoring in pediatric HIV management?
To optimize drug dosing, especially in cases of suspected toxicity or treatment failure - How does HIV affect the renal system in children?
It can cause HIV-associated nephropathy and increase the risk of acute kidney injury - What is the impact of HIV on the endocrine system in children?
It can lead to growth hormone deficiency, thyroid dysfunction, and adrenal insufficiency - How does HIV affect the hematological system in children?
It can cause anemia, neutropenia, and thrombocytopenia - What is the role of nutrition support in the management of HIV-infected children?
To promote growth, support immune function, and improve response to antiretroviral therapy - How does HIV affect neurocognitive development in children?
It can lead to developmental delays, cognitive impairment, and motor deficits - What is the impact of HIV on oral health in children?
Increased risk of dental caries, periodontal disease, and oral opportunistic infections - How does HIV affect the gastrointestinal system in children?
It can cause chronic diarrhea, malabsorption, and increased susceptibility to enteric pathogens - What is the role of adherence support in pediatric HIV management?
Critical for maintaining viral suppression, preventing drug resistance, and optimizing treatment outcomes - How does HIV affect the skin in infected children?
Increased susceptibility to bacterial, fungal, and viral skin infections, as well as HIV-specific dermatoses - What is the impact of HIV on adolescent sexual and reproductive health?
Increased risk of sexually transmitted infections, challenges in disclosure to partners, and need for contraception counseling - How does HIV affect the risk of malignancies in children?
Increased risk of certain cancers, particularly lymphomas and Kaposi's sarcoma - What is the role of psychosocial support in the care of HIV-infected children?
To address mental health issues, support adherence, and promote overall well-being - How does HIV affect the immune reconstitution in children on ART?
Can lead to immune reconstitution inflammatory syndrome (IRIS) with paradoxical worsening of symptoms - What is the impact of HIV on school performance and cognitive function in children?
Can lead to learning difficulties, attention problems, and decreased academic achievement - How does HIV affect the risk of vaccine-preventable diseases in children?
Increased susceptibility and potentially more severe course of vaccine-preventable diseases - What is the role of transitional care for HIV-infected adolescents?
To prepare for and support the transition from pediatric to adult HIV care services - How does HIV affect growth hormone axis in children?
Can lead to growth hormone resistance and impaired linear growth - What is the impact of HIV on puberty in infected children?
Can cause delayed onset of puberty and altered pubertal progression - How does HIV affect the risk of autoimmune diseases in children?
Increased risk of certain autoimmune conditions due to immune dysregulation
