|Only recently have interventions to reduce transmission of HIV from mother to child been available even in industrialised countries. Now, as shorter, less complex and cheaper drug regimes are proving effective in reducing transmission, these interventions are becoming more widely available in developing countries. For instance, recent research has shown that a single oral dose of the fairly inexpensive anti-retroviral drug nevirapine given to an HIV-infected woman in labour and another to her baby within three days of birth results in a reduction in the transmission rate similar to that achieved by a short course of AZT. However even the cheapest regime remains costly relative to per capita spending on health in many countries, so careful monitoring and evaluation of the success of interventions to reduce transmission of HIV from mothers to children is important.
Strategies to reduce mother to child transmission generally begin by supporting primary prevention of HIV among women likely to become pregnant. It is only once this strategy has failed and sexually active women of childbearing age are infected that other strategies come in to play.
Next in line is reproductive choice. Women considering pregnancy are informed of the implications of childbearing for the HIV-infected and are encouraged to find out their HIV status through voluntary counselling and testing. Those that test positive should be further counselled on the implications of pregnancy and given advice about appropriate contraceptive use.
HIV-positive women who become pregnant may have a number of options open to them if they know about their infection. For this reason, routine counselling and voluntary, confidential testing of pregnant women is an essential element in programmes designed to reduce transmission from mother to child. Once a pregnant woman knows her status, there are two major (and complementary) prevention strategies open to her. First, she may take anti-retroviral drugs (ARVs) for the last weeks of pregnancy or around delivery. Secondly, she may avoid breastfeeding the child. The second strategy is possible without the first-- indeed it is likely to avoid up to half of all vertical transmission. It appears that anti-retroviral treatment followed by breastfeeding may also cut the risk of vertical transmission, at least for women who breastfeed only up to six months. Recent developments in treating mothers just before delivery and both mother and infant just after delivery have had success in reducing HIV transmission even among women exclusively breastfeeding for three months and weaning. As new methods are validated, programmes should be prepared to monitor service delivery and availability and evaluate effects.
|Indicators of service provision in mother to child transmission should ideally cover provision of counselling and voluntary testing services for pregnant women, the availability and affordability of AZT during pregnancy, provision of advice on infant feeding and the availability and affordability of alternatives to breastmilk. However, at the time this guide was written, no standard set of indicators had been decided on or tested.
Inputs must be a factor in assessing outputs. Counselling that includes information about ARVs during pregnancy is not particularly helpful where ARV therapy is not available or affordable.
As with regular VCT services, the quality of counselling services will be an important component in evaluating the provision of prevention strategies to pregnant HIV-positive women. The issues are complex, involving shared confidentiality with a partner, future prevention and fertility decisions and infant feeding decisions. The latter in turn involves consideration of resources and possible exposure to illness (for the infant) and stigma (for the mother).
Confidentiality is an important factor which increases the challenges inherent in developing indicators. For example, the percentage of HIV-infected mothers not breastfeeding might be an important indicator of a successful prevention programme for vertical transmission, but collecting data for this indicator is virtually impossible in many settings.
Impact indicators in this area are extremely difficult to obtain. Unless prohibitively expensive PCR or LCR tests are used, HIV testing at birth (that is, ELISA antibody testing) gives no indication of the infection status of the infant. And in any case, around half of all vertical transmission in developing countries takes place after birth, during breastfeeding. Follow-up would be nearly impossible for routine surveillance systems. In many countries, particularly those with high pre-AIDS mortality in the under-fives and poor vital registration systems, infant and child mortality indicators are not specific enough to register changes in rates of HIV-associated mortality in infants.
Many countries have only extremely limited interventions in this area. Clearly, monitoring and evaluation choices in this area, as in any other, should depend on programme goals: if services to reduce mother to child transmission are limited, then M&E resources are likely to be better used tracking changes in other areas, where programming is stronger.