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HIVACAT

A study highlights the need for alternative drugs in Africa for patients who develop resistance to HIV drugs

17/06/2015

  • A study led by researchers at ISGlobal and IrsiCaixa concludes that antiretroviral treatment is not effective in 24% of HIV patients in Manhiça (Mozambique); 89% of these cases are due to development of resistance against the available drugs.
  • Drug-resistant virus may spread to the rest of the population, so the amount of mutated viruses in the area will increase over time. Drugs against these viruses are easily accessible in high-income countries, but they are harder to come by in places like Mozambique. That could lead to a short-term increase of AIDS mortality in the country.
  • The study notes the lack of alternative antiretroviral treatments along with monitoring tools in developing countries, which could timely detect the failure of treatments so that the necessary changes can be made to slow the progression of the disease.

 

A study published in the Journal of Antimicrobial Chemotherapy reports the lack of alternative drugs for HIV patients who develop resistance to antiretroviral treatment in Mozambique, one of the countries with the highest HIV prevalence the world. These findings confirm the need to monitor the viral load in HIV patients in order to ensure timely detection of treatment failure so that the necessary changes can be made in treatment to slow the progression of the disease and prevent the selection of drug-resistant virus that may spread to the rest of the population. The study is the result of a strategic collaboration between IrsiCaixa AIDS Research Institute, ISGlobal and the Manhiça Health Research Centre (CISM).

 

According to UNAIDS, 11% of the Mozambican population aged between 15 and 49 is HIV positive. The study was conducted in one of the regions with the highest HIV prevalence in Africa, the Mozambique Manhiça district, where 40% of the population is infected and free access to antiretroviral treatment began in 2004. The authors of the study found that 24% of the patients on ART in Manhiça have high viral loads and that 89% of these patients have developed resistance to the most commonly used antiretroviral drugs. The presence of high viral loads indicates that the virus is continuing to replicate despite treatment.

 

"The findings are very worrying," says Maria Rupérez, the study's lead author. "If the current treatment is not working, these patients will have to be switched to other drugs, but the alternatives are more expensive and not always available". Moreover, there is also a danger that resistant strains of the virus will spread to the rest of the population, aggravating the situation and jeopardizing the control of the HIV epidemic in Africa. In fact, the prevalence of ART-resistant HIV has recently increased to 5% in South Africa, Kenya and Zambia, reaching 15% in Uganda.

 

Since 2001, large-scale distribution of antiretroviral drugs and the use of standardized and simplified protocols have made it possible to treat more than 9 million people living with HIV in developing countries, particularly sub-Saharan Africa. While this increase in the number of people receiving ART is a very positive development, it also brings new challenges. Without proper monitoring, patients in whom the drugs fail to stop the replication of the virus—either because of poor adherence to treatment or because the virus has developed resistance—will continue to receive the same drug while maintaining high viral loads, a situation that facilitates the accumulation of resistant strains and more rapid progression of the disease.

 

Virologic monitoring 

 

The World Health Organization (WHO) recommends virologic monitoring to ensure that treatment failure is identified promptly and the patient can be switched to a different therapy. However, the reality is that viral load testing is not carried out in many health care centers in developing countries because of a lack of technical and economic resources. In Manhiça, the decision of changing the treatment is currently based on clinical criteria and the amount of CD4 T cells (HIV target cells) when it would be necessary to regularly analyze the viral load of patients to detect an increase as soon as possible.

 

According to Roger Paredes, principal investigator on the study, the solution is to facilitate access to a wider range of treatments and to ensure "affordable access to the new rapid viral load tests that can detect early virologic failure and are suitable for use in the health centers, as recommended by WHO". In his view, "the large-scale distribution of a simplified viral load test in developing countries would not only be a major step in the control of HIV in these patients, but would also help to prevent the spread of resistance to the rest of the population."