According to an American study, nevirapene, used alone to prevent mother-to-child transmission of HIV in developing countries, remains in the blood and in breast milk for 15 days. This time lapse is sufficient to allow the virus to mutate, with a considerable risk of eventual development of resistance.
Researchers monitored 32 Zimbabwean women, all of whom were pregnant and HIV-positive. At the time of the study they had not received the standard therapeutic protocol of a dose of nevirapene followed by a dose of zidovudine and were given a single dose of nevirapene.
None of these women showed any sign of drug resistance at the start of their pregnancy. However, fifteen days after giving birth, blood analysis showed that more than a third of them had developed resistance.
More serious still, the breast milk of 65% of these patients contained detectable viral loads of resistant viruses, with the consequent risk of transmitting the virus to their infants through breastfeeding. If these women had had access to more effective combination therapies, they would not have developed this resistance.
Another problem, this time raised by the Campaign for Fighting Diseases Foundation is that the majority of the treatments available in the poorest countries in fact rely on generic medicines produced in India. Selected by the Global Fund to Fight AIDS, Tuberculosis and Malaria, the controls that some of these undergo are not as rigorous as they are in the countries of the North.
Results of independent studies show an increase in resistance in developing countries.