(RxWiki News) HIV won't go down without a fight. Even as calls for the “end of AIDS” become stronger and more optimistic, scientists have found that HIV drug resistance is rising in Africa.
That means that increasing numbers of HIV-positive Africans have an infection that won't respond to drugs that have been effective at saving lives.
Public health experts worry that growing resistance to HIV drugs will push back the trend of decreasing AIDS-related deaths in poorer countries.
"Take your HIV medication as prescribed."
Dr. Silvia Bertagnolio from the World Health Organization in Geneva and Dr. Ravindra Gupta at University College London led the research. It was published in the Lancet, in advance of the International AIDS conference meeting in Washington, DC this week.
HIV drug resistance is a problem that the AIDS community has long feared. Genetic mutations in patients can make HIV immune to antiretroviral drugs, the main line of defense against the virus' spread.
If these strains of drug resistant HIV are transmitted from person to person, potentially millions of people could develop infections for which there is no treatment.
"Without continued and increased national and international efforts, rising HIV drug resistance could jeopardize a decade-long trend of decreasing HIV/AIDS-related illness and death in low and middle income countries,” the leaders of the study warned in a statement.
Ninety percent of people with HIV live in middle or low income countries. Countries in this category also have the vast majority of new infections – 97 percent.
This study is the first to assess the prevalence of HIV drug resistance in these regions. The researchers found that the largest concentration of drug resistance is in East and Southern Africa.
Over a period of eight years, the prevalence of HIV drug resistance in East Africa has jumped by 29 percent each year. That means that eight years after antiretrovirals had been introduced, 7.4 percent of the HIV-infected population had drug resistant HIV.
In South Africa, prevalence was lower, rising by 14 percent each year and reaching three percent overall prevalence six years after the drugs were introduced.
Drug resistance can emerge for many reasons. One major factor is patients who interrupt treatment or don't take their drugs every day as prescribed.
While the patients are off their drugs, the virus has a chance to build up resistance to the medication. If the patient then transmits the virus to another person – through unprotected sex or intravenous drug use – the drug resistant strain spreads.
Resistance to HIV drugs is not a surprise. The study authors stated that it may have been expected, in light of the scale of the expansion of antiretrovirals.
The number of people who receive the drugs in low and middle income countries reached 8 million in 2011, which is 26 times as many people as received the drugs in 2003.
In a statement, the authors said, "In view of these findings, urgent action is clearly needed to maximize the long-term effectiveness of available first-line regimens and to enhance population-level resistance surveillance and prevention efforts in national HIV treatment programmes. [This should include] the establishment of robust supply chains to prevent drug stock-outs and treatment interruptions and early identification of individuals failing therapy."
The study was released in July 2012.