Mother-to-child transmission of HIV (modelled)
It measures progress towards eliminating mother-to-child HIV transmission.
Efforts have been made to increase access to interventions that can significantly reduce mother-to-child transmission, including combination antiretroviral prophylactic and treatment regimens and strengthened infant-feeding counselling. It is important to assess the impact of PMTCT interventions in reducing new paediatric HIV infections through mother-to-child transmission.
The percentage of children who are HIV-positive should decrease as the coverage of interventions for PMTCT and the use of more effective regimens increases.
The numerator is the estimated number of children who will be newly infected with HIV due to mother-to-child transmission among children born in the previous 12 months to HIV-positive women
Estimated number of HIV positive women who delivered in the previous 12 months
Numerator / Denominator
The mother-to-child transmission probability differs with the antiretroviral drug regimen received and infant-feeding practices. The transmission can be calculated by using the Spectrum model.
The Spectrum computer programme uses the information on:
a. the distribution of HIV-positive pregnant women receiving different antiretroviral regimens prior to and during delivery (peripartum) by CD4 category of the mother
b. the distribution of women and children receiving antiretrovirals after delivery (postpartum) by CD4 category of the mother.
c. the percent of infants who are not breastfeeding in PMTCT programmes by age of the child
d. mother-to-child transmission of HIV probabilities based on various categories of antiretroviral drug regimen and infant feeding practices
The estimated national transmission rate is reported in the PMTCT summary display in Spectrum. This variable can also be calculated using the variables in Spectrum on “New HIV infections” for children 0-14 years and dividing this by the variable “Women in need of PMTCT”
There is not enough information available about other HIV transmission routes for children to include such infections in the model. In addition other modes of transmission are believed to be a small fraction of the overall infections among children. The Spectrum output variable “New HIV infections for children 0-1 years” is not used because some infections due to breastfeeding will take place after age 1 year
Over time, this indicator assesses the ability of PMTCT programmes by estimating the impact of increases in the provision of antiretroviral drugs and the use of more efficacious regimens and optimal infant feeding practice. This indicator is generated from a model, which provides estimates of HIV infection in children. The estimated indicator is reliant on the assumptions and data used in the model. The indicator may not be a true measure of mother-to-child transmission. For example, in countries where other forms of PMTCT (e.g. Caesarean section) are widely practised, the indicator will overestimate mother-to-child transmission. It also relies on programme data that often captures antiretroviral drug regimens provided rather than taken, thus could underestimate mother-to-child transmission.
This indicator allows countries to assess the impact of PMTCT programmes by estimating the HIV transmission rate from HIV positive women to their children. It is difficult to follow up mother–children pairs, particularly at national level, because of the lag in reporting and the multiple health facility sites that mother-child pairs can visit for the wide range of PMTCT and child care interventions delivered over a timespan. In countries where data are available, facility attendance is high, and confirmatory tests are conducted systematically, efforts should be made to monitor the impact through directly assessing the percentage of children found to be HIV-positive among those born to HIV-positive mothers. All countries should make efforts to monitor the HIV status and survival of children born to HIV-positive women, gathered during follow-up health care visits.