Friday, October 02, 2009

Preventing Mother to Child Transmission of HIV in Mwandi, Zambia- A Success

Welcome to this installment of the AIDS Pandemic, a podcast hosted by Dave Wessner of the Department of Biology at Davidson College. I am Sarah Bertram.

This past summer, I traveled to Mwandi, Zambia through a Davidson biology and pre-medical program. Mwandi is a predominantly Lozi village of about 7,000 people and the catchment area totals about 25,000 people. We spent 5 weeks in Africa, 3 of which were spent working in the Mwandi Mission Hospital, the Mwandi AIDS clinic, the Orphans and Vulnerable Children’s center, and the Mother and Child Health Center. We all went with a research topic to study that was based on some aspect of Mwandian life. I looked at Mwandi’s Prevention of Mother to Child Transmission of HIV, otherwise known as the PMTCT program, and its effectiveness over the past three years. Here, I will talk about my findings.

About out of every five pregnant women in Zambia is infected with HIV and without any prevention or treatment interventions, more than 300,000 babies would contract HIV from their mothers each year. Starting in 1999, many Zambian mission and government hospitals started PMTCT programs. The Mwandi PMTCT program was launched in 2005 by an American Pediatrician in conjunction with the Mwandi missionary who was going to serve as the leader of the program. The procedure for PMTCT at the Mwandi Mission Hospital is as follows: 1) discuss the PMTCT program and HIV/AIDS information during group antenatal care visits, 2) offer private pre-test counseling, 3) test the mother for HIV and CD4 counts and give her the results, and 4) offer post-test counseling and discuss further treatment and a re-test in three months. According to the hospital staff in Mwandi, HIV testing of any pregnant mother is required by law in Zambia.

If a woman tests positive, she is evaluated at the Pastoral Care Center for AIDS treatment. If she is considered a WHO stage IV or has multiple symptoms for WHO stage III, HAART treatment is usually started unless the woman chooses to undergo short-course treatment instead. Many of the HIV positive mothers choose to undergo HAART treatment because of its documented increased ability to treat HIV/AIDS symptoms and to lower the viral load by decreasing viral replication. The Mwandi hospital staff is good about giving options to the positive mothers and explaining each option and its risks and benefits. Due to the staff’s willingness to counsel and inform the HIV positive pregnant mothers of treatment options, a majority of these women decide to take part in a course of HIV/AIDS treatment in order to help themselves and to prevent the transmission of HIV to their babies.

Although record-keeping is sparse and sometimes hard to find and evaluate, some records for the PMTCT program proved helpful in evaluating the program’s success over the years. From March of 2005 to September of 2007 (before HIV testing was mandatory), 1,205 women attended an antenatal care appointment to sign up for the PMTCT program and of these 1,205 women, only 35 women or about 3% refused the HIV test. Of the 1,170 women who agreed to be tested, 24.4% tested positive for HIV. This statistic is quite high, but reflects the belief that about 1/3 to ¼ of Mwandi’s population is infected with HIV. Because the PMTCT program was in place, the HIV positive women were able to learn their status, get treatment, and prevent (for the most part) the transmission of HIV to their babies during pregnancy, delivery, and breastfeeding.

Mwandi’s PMTCT program has changed drug regimens in order to stay current with the most effective treatments. Originally, the program was based on a single dose of nevirapine given to the mother during delivery and to the baby right after birth. In April of 2006, the PMTCT program switched to a dual therapy involving both nevirapine and AZT for both mothers and babies. Starting in November of 2007, Mwandi updated its treatment regimen to the most current and effective triple therapy drug treatment. This drug therapy involves a mixture of AZT, 3TC, and NVP for the mother and baby. This new therapy has proven to be very effective and the PMTCT program workers approximate that transmission from mother-to-child rates have decreased to less than 10% and possibly even as low as 6% or 7%.

Possibly the most enticing aspect of the PMTCT program for pregnant women is the free formula feeding program provided to HIV-negative babies of HIV-positive mothers. Breastfeeding is the most common type of mother-to-child HIV transmission, so by providing free formula for those babies who test negative (after 6 weeks of age), the worry of transmission by breastfeeding can be alleviated. Currently there are over 100 babies receiving infant formula and most, but not all, are HIV-negative babies of HIV-positive mothers who participated in the PMTCT program. The program has never resulted in a case of child dysentery, a common negative outcome of formula feeding programs, which is often a result of incorrectly boiled water used to make the formula. This clean record is a result of the care and attention put forth into teaching the mothers how to correctly make the formula and clean the bottles.

Compared to many other Sub-Saharan African PMTCT programs, Mwandi’s program is doing a very good job of keeping the program advancing, as far as the number of women being treated and the updates to newer forms of drug therapies. The program could however still make larger strides in incorporating more women from far out in the catchment area and by possibly providing more rural village outreaches for the sole purpose of PMTCT.


helen said...

Where is the research to back up your statement that "Breastfeeding is the most common type of mother-to-child HIV transmission". I would also like to know who is providing the free formula?

Alexandra Hasselkuss said...

You may be interested in reading the chapter on “HIV and Breastfeeding” in Gabrielle Palmer’s The Politics of Breastfeeding.

I was concerned with your statement that: “Possibly the most enticing aspect of the PMTCT program for pregnant women is the free formula feeding program provided to HIV-negative babies of HIV-positive mothers.” Despite the risk of transmission, the majority of HIV-infected women who breastfeed do not infect their children (research estimates 5 – 20% of infants contract HIV through breastfeeding). The risks and long-term ramifications of NOT breastfeeding in a country such as Zambia can be lethal, and not just from dysentery as you mention.

Are all the AFASS (acceptable, feasible, affordable, sustainable, and safe) criteria for formula feeding being met at this PMTCT program? Guidance from the WHO Consensus Statement (2006) states: “Exclusive breastfeeding is recommended for HIV-infected women for the first six months of life unless replacement feeding is AFASS for them and their infants before that time.”

We shouldn’t just flippantly imply that providing formula to HIV-infected mothers is the answer. If AFASS conditions are truly met, then, yes, avoidance of breastfeeding is the surest way to avoid MTCT, but the majority of women in countries such as Zambia cannot meet these conditions long-term. This is something to consider about your PMTCT program in Zambia. HIV and infant feeding policies have (unintentionally) caused much infant death in the developing world and proved that, in most cases, breastfeeding is essential.

To quote Dr. Nigel Rollins, professor of Maternal and Child Health at University of KwaZulu-Natal, South Africa (2007): “We all knew that not breastfeeding in Africa could kill, but somehow we expected HIV-infected mothers to be different. We were wrong.”