Introduction to Congenital HIV Infections

Congenital HIV infection, also known as perinatal or vertical HIV transmission, occurs when an HIV-positive mother transmits the virus to her child during pregnancy, labor, delivery, or breastfeeding. With proper interventions, the risk of transmission can be reduced to less than 1%.

• HIV (Human Immunodeficiency Virus) is a retrovirus that attacks the immune system
• Without intervention, transmission risk is 15-45%
• Globally, an estimated 1.4 million HIV-positive women become pregnant each year

Understanding the mechanisms of transmission, clinical course, and management of congenital HIV is crucial for healthcare providers to prevent transmission and optimize outcomes for affected infants.

Transmission of Congenital HIV

The risk of vertical transmission of HIV can occur at different stages:

Timing of Transmission

• In utero: Accounts for about 25-40% of infections
• Intrapartum: Accounts for 60-75% of infections
• Postpartum: Through breastfeeding, can add an additional 14% risk

Factors Influencing Transmission

• Maternal viral load: Higher viral loads increase transmission risk
• Maternal CD4 count: Lower CD4 counts increase risk
• Duration of ruptured membranes
• Mode of delivery: Elective C-section can reduce risk in certain situations
• Antiretroviral therapy (ART) use during pregnancy and labor
• Infant prophylaxis after birth
• Breastfeeding practices

Prevention Strategies

• Universal HIV screening during pregnancy
• Antiretroviral therapy for all HIV-positive pregnant women
• Intrapartum antiretroviral prophylaxis
• Antiretroviral prophylaxis for newborns
• Avoidance of breastfeeding in settings where safe alternatives are available

Clinical Manifestations of Congenital HIV

The clinical presentation of congenital HIV can vary widely, from asymptomatic infection to severe immunodeficiency:

Neonatal Period

• Most infants are asymptomatic at birth
• Non-specific findings may include:
  • Intrauterine growth restriction
  • Hepatosplenomegaly
  • Lymphadenopathy

Infancy and Early Childhood

• Failure to thrive
• Recurrent bacterial infections
• Persistent oral candidiasis
• Lymphoid interstitial pneumonitis
• Developmental delay

AIDS-defining Illnesses

• Pneumocystis jirovecii pneumonia
• Cytomegalovirus disease
• Mycobacterium avium complex infection
• Cryptococcal meningitis
• HIV encephalopathy

Long-term Complications

• Chronic lung disease
• Cardiovascular complications
• Renal disease
• Neurocognitive impairment
• Malignancies (e.g., Kaposi sarcoma, lymphomas)

Diagnosis of Congenital HIV

Diagnosing congenital HIV requires a systematic approach due to the presence of maternal antibodies in infants:

Maternal Diagnosis

• HIV antibody testing during pregnancy
• Confirmation with Western blot or HIV RNA testing

Infant Testing

• Virologic tests (preferred for infants <18 months):
  • HIV DNA PCR
  • HIV RNA PCR
• Timing of virologic testing:
  • 14-21 days of life
  • 1-2 months of age
  • 4-6 months of age
• Antibody testing:
  • Not reliable before 18 months due to maternal antibodies
  • Used for definitive diagnosis after 18 months

Additional Investigations

• CD4 count and percentage
• HIV viral load
• Complete blood count
• Liver and kidney function tests
• Screening for co-infections (e.g., hepatitis B, hepatitis C, tuberculosis)

Management of Congenital HIV

Management of congenital HIV focuses on early initiation of antiretroviral therapy, prevention of opportunistic infections, and comprehensive care:

Antiretroviral Therapy (ART)

• Initiate ART as soon as possible after diagnosis
• Choice of regimen based on:
  • Age and weight of the infant
  • Potential drug interactions
  • Resistance patterns
• Typical first-line regimens include:
  • Two nucleoside reverse transcriptase inhibitors (NRTIs) plus a protease inhibitor or integrase inhibitor
• Regular monitoring of adherence, side effects, and treatment response

Prophylaxis for Opportunistic Infections

• Pneumocystis jirovecii pneumonia prophylaxis for all HIV-exposed infants starting at 4-6 weeks of age
• Other prophylaxis based on CD4 count and clinical status

Immunizations

• Follow routine immunization schedule with some modifications
• Avoid live vaccines in severely immunocompromised children

Nutritional Support

• Regular growth monitoring
• Nutritional counseling and supplementation as needed

Neurodevelopmental Assessment and Support

• Regular developmental screening
• Early intervention for developmental delays

Psychosocial Support

• Counseling for families
• Disclosure planning and support
• Mental health services

Long-term Follow-up

• Regular monitoring of CD4 count and viral load
• Screening for long-term complications
• Transition planning to adult care

Future Directions

• Development of long-acting antiretroviral formulations
• Research on HIV cure strategies
• Improved point-of-care diagnostics for infants