Promising new combination therapy reduces MTCT

Zambia's government has begun using a new drug in its prevention of mother-to-child transmission (PMTCT) programme, in an effort to reduce drug resistance in both mother and infant.

Dr Miriam Chipimo, reproductive health specialist at the Central Board of Health (CBoH), told PlusNews that Nevirapine was now being used in combination with the anti-AIDS drug, Zidovudine, also known as AZT.

Although a single dose of Nevirapine reduces the rate of HIV transmission, scientists have found that a combination of antiretrovirals (ARVs) can result in lower rates of Nevirapine resistance.

Researchers have long been hunting for an alternative to Nevirapine, a cheap and highly effective drug used to prevent transmission of the HI-virus from mother to child during birth, because up to two-thirds of women are resistant to the drug when they access antiretroviral therapy, which consists of three drugs with Nevirapine often one of the preferred options.

"[The move] is in line with the World Health Organisation (WHO), which recommended this addition early this year after studies showed that administration of a single drug causes resistance trends in children," Chipimo said.

Presentations at the 12th Annual Retrovirus Conference in Boston in 2005 showed that various drug combinations recorded low rates of resistance, offering women a relatively inexpensive and convenient alternative.

Two studies, one in Cote d'Ivoire and the other in Botswana, reduced transmission rates to about five percent in the four to six weeks after birth.

Zambia's new drug regimen could reduce HIV transmission to as little as two percent, while a single dose of Nevirapine reduces transmission from 36 percent to 12 percent.

Despite the feared resistance trends in the use of single-dose Nevirapine, Chipimo stressed that the drug remained essential in antiretroviral therapy.

A few health centres in the capital, Lusaka, are administering the combination therapy and the government has begun training staff to use the new treatment.

"About 50 percent of all health personnel working within the PMTCT programme will be trained by mid this year. The bulk of training is taking place in provinces which have the most births in the country: Lusaka, Southern and Copperbelt," she said.

Dr Moses Sinkala, team director of Lusaka District Health Management, noted that implementing the new drug regimen has not been easy.

"Some of the complications arise with mothers who do not have any ailments and do not require long-term ARV treatment. This has led to problems with adherence to the treatment, as they have no motivation to take the drugs," he noted.

Treatment starts when an HIV-positive woman is 32 weeks pregnant and continues for a week after delivery, while the baby receives the standard single dose of Nevirapine at the onset of labour and another dose after birth.

"It is important to note that AZT alone is less superior than the single dose of Nevirapine in preventing the transmission of the virus from mother to child. This is why mothers are being told not to forget to take the single dose of Nevirapine when labour starts."