Rising ARV resistance threatens HIV fight

The prevalence of drug-resistant HIV strains in Uganda has risen from 8.6 percent to 12 percent in the last five years, one of the highest rates in Sub-Saharan Africa, according to a recent study.

The PharmAccess African Studies to Evaluate Resistance (PASER) monitoring cohort study report for 2008-2012 found that the prevalence of transmitted drug resistance among people who have never taken life-prolonging antiretroviral (ARV) medication was substantially higher in Uganda.

ARVs were available at least five years earlier in Uganda than in the five other PASER countries - Kenya, Nigeria, South Africa, Zambia and Zimbabwe - where drug resistance was estimated at 5 percent in selected areas of those countries.

The Ugandan study was based on results from the capital, Kampala, the western town of Fort Portal, and the eastern town of Mbale.

HIV drug resistance occurs when patients do not respond to prescribed ARVs, and their health deteriorates despite taking the drugs correctly and consistently. Patients who have become resistant must start taking a more expensive second-line regimen of medication. HIV-positive people with drug-resistant strains can transmit them to others.

"Drug-resistant HIV variants selected during ART [antiretroviral treatment] failure have the potential to limit the response to subsequent lines of treatment, and constitute a reservoir for onward transmission [of drug resistance] to newly infected individuals," the authors said. "Drug-resistant HIV may severely restrict therapeutic options, and treatment costs will greatly increase when more people need second- and third-line ART regimens."

According to the study, the overall drug resistance in patients starting on first-line treatment in the six PASER countries stands at 5.6 percent. Most patients had resistance to a class of ARVs called non-nucleoside reverse transcriptase inhibitors (NNRTIs), which include commonly used medications such as nevirapine and efavirenz.

The report revealed that poor treatment adherence to ARVs, shortage of health professionals, limited training, deficient adherence counselling, inconsistent drug supply and weak enforcement of quality standards were among the causes of HIV drug resistance.

"The supply system inefficiencies many times have created stock-outs that have led to individuals not filling their monthly prescriptions for days. Patients have even been sharing medicines in some places," Denis Kibira, medicines adviser at the Coalition for Health Promotion and Social Development Uganda, told IRIN/PlusNews.

To address mounting ARV resistance in the region, national HIV treatment programmes should be strengthened, including robust supply chains, routine viral load monitoring, access to second- and third-line drug regimens, with a solid framework for resistance surveillance, the study's authors noted.

"There is no room for complacency. Without cumulative resistance surveillance data and commitment on the part of the World Health Organization (WHO), international funding agencies and national governments to address programmatic challenges, emerging drug resistance has the potential to curb, and even reverse, further progress on breaking the HIV epidemic," they said.

"Improved quality of HIV/AIDS care and treatment, increased programmatic efficiency and continued international funding support are urgently needed to reach the goal of universal and sustainable access."

Dr Joshua Musinguzi, the acting programme manager of the AIDS Control Programme at the Ministry of Health, told IRIN/PlusNews: "Drug resistance is an issue we are keeping an eye on, there are some cases of treatment failure among persons on ART. If we don't act and respond appropriately, we shall have a problem - the second line of treatment is usually expensive. This will raise treatment and management costs."

Experts warn that rising drug resistance threatens the global fight against HIV. "If resistance increases it results in a corresponding rise in the cost of ART and makes the goal of universal access to ART that more difficult to achieve," said Prof Peter Mugyenyi, one of the study's authors and the executive director of Uganda's Joint Clinical Research Centre, the first centre in the country to provide ARVs.

"Other subsequent complications are too hideous to contemplate,” he said, “but will happen if timely preparations and strategic plans and actions are not taken now."