Table 2 Probability of mother-to-child transmission of HIV (%)
Duration of breast feeding in the general populationTreatmentMixed breast feedingReplacement feedingExclusive breast feeding
Approximately 6 monthsNone262023
Single-dose nevirapine171114
Dual-prevention ARV1047
Triple-treatment ARV423
Approximately 12 monthsNone30.5
Single-dose nevirapine21.5
Dual-prevention ARV14.5
Triple-treatment ARV5
Approximately 18 monthsNone35
Single-dose nevirapine26
Dual-prevention ARV19
Triple-treatment ARV6
  • Mixed breast feeding: in addition to replacement feeding rates

  • First six months: 1% per month for first 6 months (total 6%) (based on reports by Iliff et al45 and Rollins46: approximately double the hazard of exclusive breastfeeding).

  • Thereafter: 0.75% per month for next 6 months (total 4.5%) and for next 6 months (total 4.5%) (based on BHITS meta-analysis47: 8.9% per 100 person-years).

  • Triple-treatment ARV: in absence of data, assume 2% additional transmission for first 6 months, then 1% for next 6 months and again 1% for next 6 months.

  • Replacement feeding

  • No treatment: 20%: based on 2004 UNICEF/UNAIDS/WHO/UNFPA review.40

  • Single-dose nevirapine: based on data from Jackson et al (11.8% at 6–8 weeks in breastfeeding population)41 and Moodley et al (10.7% among replacement feeding population).42

  • Dual-prevention ARV: based on Ditrame (6.5% at 6 weeks (with some breastfeeding transmission))43 and PPHT-2 (1.9–2.8% among replacement feeding population).44

  • Triple-treatment ARV: based on western studies quoted in report by UNICEF/UNAIDS/WHO/UNFPA.40

  • Exclusive breast feeding

  • In addition to replacement breastfeeding rates: 0.5% additional transmission per month (total 3%) (based on reports by Iliff et al45 and Rollins46).

  • Triple-treatment ARV: in absence of data, assume 1% additional transmission.