Title: Postnatal transmission of HIV through breastfeeding
1Postnatal transmission of HIV through
breastfeeding
Ghent IAS working group on HIV infection in
women and children
2MTCT through Breastfeeding
- HIV is present in breastmilk
- Breastfeeding poses a substantial risk for
acquisition of infection for the infant - Prolonged breastfeeding can double the overall
risk of mother-to-child transmission (Nduati et
al, 2000)
3Breastmilk infectivity Richardson et al, JID
2003
- Estimated probability of transmission per litre
breast milk 0.00064, or one infection per 1500
litre ingested - Estimated probability per day of exposure
0.00028, or about 10 infections per 100
child-years of breastfeeding - Infectivity does not vary over age
4Risk factors for transmission through
breastfeeding
- Maternal HIV status (CD4 count)
- Maternal plasma and/or milk RNA viral load
- Duration of breastfeeding
- Mode of feeding EBF or MBF
- Breast health
- Infant factors (oral thrush)
5Although peripartum antiretroviral therapy
substantially and significantly reduces the risk
of MTCT during that period, infants who are
breastfed remain at risk of acquiring infection
until completely weaned However, there is no
evidence to suggest that the peripartum therapy
itself influences the risk of acquisition of
infection in the breastfeeding period
6Postnatal transmission (gt 4 wks) BHITS
meta-analysis
- 9/10 eligible trials, all in Africa
- 4085 breastfed, singleton infants
- 993 infected, of whom 314 early transmission, 225
LPT, while for 454 timing was unknown - LPT could contribute as much as 42 to the
overall rate of MTCT
7BHITS Further results
- 3025 children were uninfected at 4 wks of age, of
whom 223 became infected subsequently (LPT) - Estimated rate of LPT was 8.9 per 100 child-years
of breastfeeding (95 CI 7.8-10.2) - LPT risk was roughly constant over time as
indicated by the hazard function from co-variate
adjusted analysis - Cumulative probability of LPT at 18 months was
9.3 (3.8-14.8) , allowing for loss to follow up
and conditional on breastfeeding
8BHITS risk of LPT
- In Multivariate analyses, maternal CD4 count,
and gender were significantly associated with LPT
but trial location was not - lt200 CD4 8-fold increased risk
- 200-499 3.5 fold increased risk
- gt 500 reference group
- Girls 40 reduced risk compared to boys
9The biggest issue remains what to do about
infant feeding?
10Exclusive breastfeeding
- Several studies are ongoing in South Africa,
Cote dIvoire, Zambia and elsewhere, to - evaluate the feasibility and acceptability
of - exclusive breastfeeding for up to 6 months
- assess impact of temporary addition of
- water, milk and other food
- estimate the rate of breastfeeding
- transmission and associated risk factors
- assess the practicality of abrupt cessation
- of breastfeeding at 4 6 months
11Research on the prevention of mother-to-child HIV
transmission now concentrates mostly on the
breastfeeding period, including antiretroviral
prophylaxis to mothers or their infants as well
as other interventions relating to infant feeding
practices