PMTCT improving but services only reaching small percentage of women in need

Several sessions at the 2006 PEPFAR Implementers' meeting held this June in Durban , focused on treatments for PMTCT prophylaxis.

The ongoing focus of research has been to identify more efficacious PMTCT interventions particularly in breastfeeding populations, said Dr Mbori-Ngacha. She presented a graph which showed the sequential improvements that have been made in the regimen over the past several years.

Table 1: Observed transmission rates according to intervention in Africa , 1995-2004

The conclusions that we can draw from these is that combination regimens are more efficacious and points to the need to... move beyond single dose nevirapine (sd-NVP) which is an important backbone of our programmes and to increase the efficacy of our programmes by adding combinations, she said.

More data on effectiveness of nevirapine after PMTCT
Although it does appear more effective, the reason why the short course of AZT/3TC after sd-NVP was originally investigated was to see if it could prevent the development of resistance to nevirapine that might impair future responses to ART. However, more data were presented at the Implementers' Meeting suggesting that this may not be a great concern as long as enough time had passed since nevirapine exposure.

The study was conducted in Lusaka , Zambia , where since May 2004, several thousand women have started taking ART, some of whom had previously taken sd-NVP for PMTCT. Despite concerns about nevirapine resistance, women who received sd-NVP (n=584) for PMTCT and who later went on ART had similar clinical and immune responses as those who did not receive SD-NVP (n=4798). However, on average women initiated ART treatment roughly 15 months after sd-NVP exposure, and at least six months had passed between sd-NVP use and ART for around 80% of the women. According to the study abstract further studies are needed to determine the potential impact on treatment failure of timing between NVP exposure and ART initiation. (Chi)

Mothers on ART
But the most effective prevention regimen so far would appear to be ART itself. This has been widely instituted in industrialised countries where the rate of MTCT is extremely low. At the Implementers meeting, some of the first data to show the effects of ART upon MTCT in Africa were presented as well as how it compares to the effect of sd-NVP in women with less advanced HIV disease. Rates of transmission are markedly lower among women on ART despite the fact that their advanced disease would have been associated with high rates of transmission off of treatment.

Table 2: PMTCT and women on ART in programmatic settings

Uganda study Homsy, SA study Van der Merwe

Still a long way to go
But even as we try to improve the efficacy of our regimens, the harsh reality is that in terms of broad coverage of our PMTCT programmes, we still have a long way to go, said Dr Mbori-Ngacha. Even in most of the PEPFAR countries, only a very low percentage of pregnant women deliver having received PMTCT services.

There are several reasons for the low coverage of PMTCT services that relate to individual health seeking behaviour, health infrastructure issues, as well as the quality of our services. This results in many broken links in the continuum of care. We need to find innovative ways to reach women who are not accessing health facilities and we need to establish linkages between health facilities and community based traditional health workers such as birth attendants.

Also, she said that breastmilk transmission attenuates the effect of our intervention and continues to be a main source of infection for children. In many settings, safe and affordable alternatives to breastmilk are simply not available, and even if they are, safe drinking water is not . Furthermore, formula feeding carries stigma because it is often a clear indication to others of the mothers HIV status. ART may represent the best option for HIV-infected mothers who are breastfeeding and ongoing studies in Malawi and Kenya are currently evaluating this.

Also enlisting male partner support and ongoing involvement is critical to ensure that the uptake of PMTCT services is universal, said Dr Mbori-Ngacha.

Finally, in the postnatal period, Dr Mbori-Ngacha believes that HIV care and follow-up need to be better integrated into maternal child health services and that many women and children are falling through the gaps.

It is important that we link women and children in PMTCT programmes to care and treatment services. This is an area that continues to be a challenge, particularly since PMTCT is offered usually in a separate location from treatment services.

References
Chi B. Maternal immune response and clinical outcomes on NNRTI-based antiretroviral therapy following exposure to single-dose nevirapine for prevention of mother-to-child HIV transmission. The 2006 HIV/AIDS Implementers Meeting of the Presidents Emergency Plan for AIDS Relief, Durban, South Africa, abstract 88, 2006.

Homsy J. Mother-to-child HIV transmission and infant mortality among women receiving highly active antiretroviral therapy (HAART) in rural Uganda . The 2006 HIV/AIDS Implementers Meeting of the Presidents Emergency Plan for AIDS Relief, Durban, South Africa, abstract 97, 2006.

Mbori-Ngacha D. The 2006 HIV/AIDS Implementers Meeting of the Presidents Emergency Plan for AIDS Relief, Durban, South Africa, Keynote Address.

Van der Merwe K et al. Triple therapy improves the risk of mother-to-child transmission in pregnant women with advanced HIV infection analysis of initial findings in a prospective observational cohort study. The 2006 HIV/AIDS Implementers Meeting of the Presidents Emergency Plan for AIDS Relief, Durban, South Africa, abstract 133, 2006.