Originally written by Lucia Mvula, for Impatient Optimists.

Around one in five pregnant women in Zambia are HIV positive. Scientific progress means that these women can now take medicines that prevent them from transmitting HIV to their babies. And with large investment in prevention of mother-to-child transmission services in Zambia over the past few years, many HIV positive mothers are giving birth to HIV negative babies.

But many more are still being born HIV positive.

Why is this? What’s getting in the way of preventing these preventable HIV infections from happening?

One of the main reasons why these medicines are not reaching the women who need them is that women are opting not to access pre- and postnatal services, even when they are available. When it comes to preventing HIV infection, understanding why this is is as crucial as any biomedical breakthrough.

Many Zambian women, particularly in rural areas, choose to deliver their child at home, using the services of a traditional birth attendant, rather than going to a health centre. Put simply, many women feel better cared for by their birth attendants because they treat mothers with respect and compassion—while many over stretched, underpaid health care workers don’t.

Practical issues also play a major part. In the majority of cases, a birth attendant will live nearby whereas a health centre can be kilometres away and many women simply can’t afford transport to get there.

Would you want to walk for hours while in labour? Not surprisingly, many Zambian women don’t want to either.

Many health centres are not only far away, but also lack the necessary health supplies, such as clamp cords and antiseptic. When they are present, mothers often must bear the costs. Compare that to birth attendants, who will provide free services or ask very little for them, often a material trade.

But the downside of birth attendants is that the majority are unable to intervene in cases when complications arise, which means many women and their babies die during delivery.

What’s more, they do not have adequate information on HIV or possess essentials such as gloves for delivery. If the mother-to-be or the birth attendant is HIV positive, there is a high risk transmission will occur to the child.

The work I do at Alliance Zambia focuses on engaging communities because we believe that they stand on the frontline of the HIV response and their involvement is critical if we want to prevent HIV infections and meet the targets around Millennium Development Goal #6.

Working with communities has helped us understand the huge influence birth attendants have on women, particularly in rural areas. Under a project funded by the UK Department for International Development, last year we worked with birth attendants, explaining the services for them to pass on to the women coming to them for help. We also provided them with information on HIV transmission and prevention, how to spot signs of complications during pregnancy, and the importance of referring women to health centres for specialist services.

We also gave technical and financial support to grassroots, community based organisations such as Young Happy Healthy and Safe, which works in rural ChipataThe project has enabled grassroots organisations to buy essential items needed for deliveries, give money to women for fuel or transport to health centres, and offer incentives to birth attendants to conduct awareness sessions in communities and among their peers.

In areas where the project was implemented, birth attendants began referring women to health centres then escorting them when labour began. We also saw good relationships between birth attendants and health centres emerge as health centre staff began to see the value of birth attendants in ensuring pregnant women access the health services they and their babies need.

Projects such as this demonstrate that science alone is not enough—understanding why people act as they do must not be left out of the equation.

Learn more about the International HIV/AIDS Alliance’s What’s Preventing Prevention Campaign here.

For more on the Millennium Development Goals set for expiry in 2015, check out the USAID video above.