The human immunodeficiency virus is a retrovirus (Retroviridae family) that contains RNA and affects the immune system by attacking CD4+ T-lymphocytes, macrophages and dendritic cells.
Breast milk and HIV transmission
Breast milk contains viruses, so it may be dangerous for a newborn to be fed by breastfeeding. Breastfeeding drastically increases the risk of HIV transmission from mother to child. The transmission rate through breastfeeding is at least 16%, whereas prolonged breastfeeding is estimated to double the overall infant HIV infection rate.
Transmission ranges from 14% to 25% in Europe and America and from 13% to 42% in developing countries when no prevention measures are taken.
- Overall mother-to-child transmission without breastfeeding – transmission rate was estimated to vary from 15 to 25%;
- Overall with breastfeeding to 6 months – 20-35%;
- Overall with breastfeeding to 18-24 months – 30-45;
It was reported that with the antiretroviral therapy, planned C-section and avoidance of breastfeeding the transmission rate in Europe and the USA may be decreased below 2%.
In developing countries, antiretroviral prophylaxis during pregnancy and labor with only one drug can decrease the rate of infection in breastfed infants until two or three months of age to about 10%, and with combination therapy to about 7% at six weeks. Although as breastfeeding continues the risk of HIV transmission remains.
In one study transmission through breastfeeding was estimated to be 0.00064 per liter of breast milk ingested and 0.00028 per day of breastfeeding.
Read also: Women with HIV
Factors associated with transmission via breastfeeding
- Increased RNA viral load in breast milk;
- Increased RNA viral load in plasma;
- Clinical disease progression or low CD4+ count (advanced immunosuppression);
- Mastitis (inflammation of the breast), abscess, cracked nipples and other nipple lesions;
- Local immune factors in breast milk;
- Mother’s nutrition is supposed to influence the HIV infection overall and the risk of transmission through breastfeeding;
- Damage of the oral mucosa of the child (oral thrush or Candida infection) increases the risk of infection;
- Duration of breastfeeding (especially longer than for 6 months) – the longer the child is breastfed, the greater is the risk of transmission (the cumulative risk);
- Mode of breastfeeding – exclusive breastfeeding is associated with lower risk of HIV transmission;
- Less vigorous suckling, milk stasis, and increased leakage of the virus across milk ducts;
Prevention of mother-to-child HIV transmission
- A woman should obligatory receive ART both during pregnancy and after the delivery;
- The planned C – section should be considered;
- It is better to avoid breastfeeding when a child has not been infected before. Replacement feeding is recommended;
- Exclusive breastfeeding until the age of 6 months with early cessation when formula milk is not available. Wet-nursing by a non-infected woman may be an option as well;
- Cease breastfeeding when there are any signs of breast inflammation or nipple lesions;
- For premature infants breast milk may be pasteurized – such milk is considered to be safer for consumption;