Aids : Effectiveness of antiretroviral therapy demonstrated in Africa

Tritherapies using antiretroviral drugs have proved their worth in industrialized countries in the fight against Aids. However, in Sub-Saharan Africa, where 70 % of people infected with HIV live, access to such treatments is extremely limited. High cost, complicated procedures, combined with inadequate infrastructures for following up patients or capable of delivering medicines regularly partly explain this situation. Moreover, efficacy of antiretroviral agents might not be the same for some HIV strains present in Africa. And not enough is yet known about the response to therapy (viral resistance, adverse effects and so on), notably in patients in advanced stages of immune deficiency. These factors are considered as obstacles to mounting concerted therapy programmes in Africa. For some government authorities they provide the arguments for concentrating control campaigns solely on prevention with no involvement of antiretroviral drugs.

Since 1998 the Senegalese government has been developing a programme facilitating access to Aids treatments (1). Within this, an assessment programme, coordinated by the IRD and the Senegal National Committee for Aids Control, and financed by the Agence nationale de recherches sur le sida (ANRS), has been deployed aiming to determine the effectiveness, the tolerance, the acceptability and feasibility of the standard form of antiretroviral therapy. This study was conducted in a cohort of 58 patients aged between 16 and 56 years, having high viral load and low CD4 cell count. Most of them (86.2%) had developed the disease before the start of the antiretroviral therapy. All received a combination treatment of two nucleoside reverse transcriptase inhibitors plus one protease inhibitor (2) The drugs were taken in three doses per day, just as in the industrialized countries. A sociological survey was done in parallel which assessed patients’ ability to contribute to part of the cost of the treatment depending on their financial resources. The rest would be subsidized by the programme.

At the end of the 18 month study, the results were comparable with those obtained in the countries of the North. Most patients (87.9 %) regularly followed the course of treatment over the whole period monitored. Also, contrary to prior assumptions, financial difficulties did not hinder adherence to the therapy. Furthermore, the same therapeutic efficacy was observed here as in the industrialized countries. After a year and a half of treatment the viral load was almost undetectable (below 500 copies/ml) in 59.3 % of cases and the CD4 cell count had risen markedly (about 180/mm3). Tolerance to antiretroviral medicines was generally good, adverse effects observed being only mild. Only two cases of viral resistance to the drugs were found.

This study gives proof that the therapeutic strategies developed in the industrialized countries can also be applied in Africa. The Senegalese initiative shows that this tritherapy method proves to be effective for most patients, even if their immunity deficiency is severe before embarking on antiretroviral treatments – and although many different strains of HIV-1 are circulating. It must be emphasized also that, contrary to results of several other studies conducted in Africa, viral resistance was rare. The researchers consider that the quality of follow-up of patients under the therapy regimens, attained by involving social workers and the regularity of medicine supply, contributed to the effectiveness. Judging by the excellent results obtained during this pilot phase, it now remains to ascertain that antiretroviral therapy maintains its efficacy over the long term and on a larger scale.

(1) Senegal, which launched its HAART in 1998, was among the first African countries, along with the Ivory Coast and Uganda, to set up a nation-wide programme to facilitate access to treatment for Aids.

(2) These antiretroviral drugs are active against two HIV targets : reverse transcriptase and protease. Both are enzymes. The first enables the viral RNA to transform into DNA so it can then become integrated with the DNA of the cell it infects. Protease builds up the constituent elements of the HIV, before it is released from the cell to spread further.