enters/infects through permeable mucosal surfaces, lymphoid tissues, lesions in mouth, intestine
Although BF infant may consume >500,000 virons, >25,000 infected cells per day, majority don’t become infected (Lewis et al, 2001)
immune factors in BM may play a role (Sabbaj et al, 2002)
Risk factors for postnatal transmission: Maternal immune status
Risk factors for postnatal transmission: Maternal viral load
Viral RNA is an important predictor of intra-partum MTCT (Leroy et al, 2001; Semba et al, 1999; Thea et al, 1997)
Plasma viral load may also be a risk factor during breastfeeding
29% transmission risk among women infected postnatally (Dunn et al, 1992)
risk of infection after 2 months associated with plasma viral load > 43k copies/ml (John et al, 2001) (OR=2.6)
predicted MTCT by 12 months, after taking into account maternal immune status, Na+ in breast milk (Semba et al, 1999) (Adj OR=1.71 log HIV load)
Risk factors for postnatal transmission: Breast milk viral load
Prevalence of breast pathologies in HIV+ women in Africa
Mastitis (clinical or sub-clinical):
Clinical exam: 7-11% (Embree, 2000; John et al, 2001)
Na+/K > 1.0: 11-12% at 6, 14 wk (Willumsen et al, 2000)
Na+ > 12 mmol/L: 16.4% at 6 wk (Semba et al, 1999)
Nipple lesions:
Clinical exam: 11-13% (Embree, 2000; John et al, 2001)
Clinical exam: 10% (Ekpini et al, 1997)
Hospitalized infants: 11% (Kambarami et al, 1997)
Breast abscesses:
Clinical exam: 12% (John et al, 2001)
Clinical exam: 3% (Ekpini et al, 1997)
Risk factors for postnatal transmission: Breast health -1
Sub-clinical mastitis is associated with higher viral load in BM (Willumsen et al, 2000; Semba et al, 1999)
Mastitis is associated with increased risk of postnatal transmission:
Kenya (Embree; > 3 mo) OR=2.3 (1.1-5.0)
Kenya (John; overall) RR=3.9 (1.2-12.7)
Kenya (John; >=2 mo) RR=21.8 (2.3-211)
Malawi (Semba; overall) OR=2.3 (1.2-4.3)
Malawi (Semba; > 6 wk) RR=3.7 (NS)
Nipple lesions and breast abscesses also associated with increased transmission
Risk factors for postnatal transmission: Breast health -2
18-20% of overall MTCT may be attributable to mastitis (estimated from mastitis prevalence and adjusted risk estimates):
18% of all transmission in first year in Malawi (Semba et al, 1999)
20% of transmission up to 2 years (John et al, 2001)
If BF accounts for 40% of all transmission, then mastitis (breast health problems) may be the cause of 50% all postnatal transmission (20/40)
Risk factor for postnatal transmission: Duration of breastfeeding
Risk of transmission persists for as long as breastfeeding is practiced
Some studies indicate that the risk of HIV transmission may be higher in the first 6 months of life (Miotti et al, 1999; Nduati et al, 2000; John et al, 2001)
Several possible explanations
higher prevalence of mastitis, breastfeeding problems
infant gut more immature, vulnerable/permeable
more breast milk consumed
Postnatal transmission of HIV: Duration of breastfeeding Ghent meta-analysis -2 (Read et al, 2002)
What about HIV transmission during the first month of breastfeeding?
Postnatal transmission of HIV: Pattern of breastfeeding
Infant mortality among children born to HIV+ mothers by early feeding pattern (0-3 months) in Harare, Zimbabwe (n=2,892) Tavengwa et al, 2002
Risk factors for postnatal transmission: Infant oral lesions
Disruption of the skin or mucous membranes in mouth and intestine believed to increase the risk of HIV transmission during breastfeeding
epithelial integrity affected by nutritional deficiencies, infection
feeding pattern, mastitis did not effect intestinal permeability (Rollins et al, 2001; Willumsen et al, 2000)
Infant oral thrush associated with increased risk of postnatal transmission
Kenya: OR=2.8 (1.3-6.2) (Embree et al, 2000)
Cote d’ Ivoire: RR=5.0 (0.5-39.8) (Ekpini et al, 1997)
Infant Feeding Options for HIV+ Mothers
WHO recommendations on infant feeding for HIV+ women
“When replacement feeding is acceptable, feasible, affordable, sustainable and safe, avoidance of all breastfeeding by HIV-infected mothers is recommended.
Otherwise, exclusive breastfeeding is recommended during the first months of life.
To minimize HIV transmission risk, breastfeeding should be discontinued as soon as feasible, taking into account local circumstances, the individual woman’s situation and the risks of replacement feeding (including infections other than HIV and malnutrition).”
New Data on the Prevention of Mother-to-Child Transmission of HIV and their Policy Implications: Conclusions and Recommendations (WHO 2001)
How Can Families Decide? -1
What is meant by ACCEPTABLE?
There are social and cultural norms about infant feeding.
Concerns about stigma associated women who do not breastfeed, suspicion of HIV
What is meant by FEASIBLE?
There are economic, behavioral, psycho-social aspects for care-giver and infant
Resources and skills are required
How Can Families Decide? -2
What is meant by SUSTAINABLE?
It must be practiced every day and night
Resources must be available throughout
It should be exclusive over first 6 months
What is meant by SAFE?
Free from contamination
Nutritious
Free from stigma
Does not spillover to general population
Infants who do not breastfeed have an increased risk of dying in the first year of life
Risk of mortality is greater among women without access to hygiene, sanitation,water
Percent of Total Population with Access to Safe Water
Percent of Total Population with Access to Adequate Sanitation
Feeding Options Currently Recommended by WHO (1998)
Breastfeeding
exclusive breastfeeding
heat-treated breast milk
wet-nursing
milks banks
early cessation of breastfeeding (as soon as feasible)
What do we know about the feasibility of exclusive breastfeeding? (BFHI/MCH/IMCI) -1
EBF rates at 6 weeks - over time and after the introduction of an education and counseling program on safer breastfeeding practices in Harare, Zimbabwe (n=9,931)
Exclusive breastfeeding rates in PMTCT programs with infant feeding counseling - Barcelona AIDS abstracts
Methods used for measuring exclusive breastfeeding produce different rate estimates
What do we know about the feasibility of early/rapid breastfeeding cessation? -1
Potential risks for infant
Dehydration
Anorexia
Later behavior problems
Malnutrition
Illness or death
What do we know about the feasibility of early breastfeeding cessation? -2 Barcelona AIDS Conference
Early, rapid cessation is possible (Uganda, Zambia, Botswana)
Problems encountered
breast engorgement; mastitis; babies crying, trouble sleeping, appetite loss, diarrhea; financial constraints with replacement feeding; family objections
more problems when cessation < 6 months (Botswana)
Trained counselors were able to help mothers overcome problems
Provision of replacement feeds, family support facilitated process
Impact on HIV transmission, survival not yet known
Breast milk contributes > 50% of the nutrient intake of children > 6 months in developing countries and won’t be easy to replace
What do we know about the feasibility of other breastfeeding options?
Heat-treated breast milk
heating milk to 56-62.5 degrees C for 12-15 min inactivates HIV in human milk (Jeffreys et al 2001)
no data on feasibility of daily use from birth
may be practical during transition period with early cessation
Use of wet nurse - no data
monitoring HIV status of wet nurse a challenge
practice may be less common because of HIV
Milk banks - no data
may be feasible in some settings (Brazil, LA Region)
What do we know about the feasibility of commercial formula?
High acceptance/adherence in some countries with access to clean water, health care, subsidized cost
postnatal follow-up also required (monitor growth, ensure adequate access/availability)
cost will make it NOT affordable for poor families to purchase
cost may make it NOT sustainable for governments
Code of Marketing of BMS protects against misuse if enacted/enforced
But “spillover” may be unavoidable if BF support for HIV-negative and status unknown mothers is not adequate
Can we make replacement feeding safer for HIV+ women?
Provide safe water & environmental conditions
Family support, community understanding
Postnatal follow-up and enhanced care
essential child health interventions
Screen mothers, target use to those most at risk
Take measures to prevent unnecessary use of RF
We must strengthen, not abandon, our efforts to support optimal infant feeding for all because of HIV. The need is even greater when PMTCT programs provide infant formula to HIV+ women.
