Here in Europe, HIV has virtually gone off the radar. It has been reduced to a chronic but eminently treatable disease that affects relatively small numbers of people, neither a major threat nor a major challenge. In Africa, however, it is a completely different story.

In Africa the HIV epidemic continues, unabated. An estimated six million people in sub-Saharan Africa alone are without access to the antiretroviral (ARV) treatment that will save their lives. For these people, HIV is a life-threatening condition and a major medical emergency.

The different perceptions of HIV go some of the way to explaining why donors think they can get away with backtracking on the promises they made to fund HIV treatment in Africa. On 27 May 2010, Médecins Sans Frontières published a new report, No time to quit: HIV/AIDS treatment gap widening in Africa, to highlight how major international funding institutions – such as PEPFAR, the World Bank, UNITAID, and donors to the Global Fund – are reneging on these pledges.

Antiretroviral treatment is lifesaving, but also lifelong: patients need to keep taking the drugs in order to stay alive. At the same time, new patients need to be started on treatment at a sufficient rate to keep up with the spread of the epidemic. When major donors like the United States begin to flatline – or even decrease – their funding, it is this initiation rate that comes under pressure.

Shortages of drugs at clinics mean new patients are getting turned away. They are told to come back later, or are sent elsewhere, and many disappear from the system completely. Without the right drugs and follow-up care, their outlook is grim, with a heightened risk of suffering complications and opportunistic infections. Quite simply, denying them access to treatment when they need it dramatically increases their chance of death.

Most donors blame the economic crisis for the spending squeeze. But some donors had clearly made plans to cut back on HIV funding before the financial crisis kicked in, reflecting the erroneous perception that the HIV emergency is over and it is now back to business-as-usual.

There are also hidden cutbacks, as a result of a donor preference for funding investment costs – buying equipment, for example, and paying for training – rather than for funding the recurrent costs of the epidemic – the ARV drugs that are so desperately needed.

The funding retreat risks undermining years of achievements made against the odds. For in spite of all the difficulties, and in spite of the poor health systems in so many African countries, there is no doubt that really significant progress has been made. No one, ten years ago, would have dared hope that there would be three million people on ARV treatment in sub-Saharan Africa by now.

The problem is that more emphasis has been put on what has been achieved so far than on what still has to be done. You could argue that HIV interventions have become a victim of their own success.

Millions of people are undergoing treatment at present, all of whom need to stay on ARV drugs to stay alive. Perhaps the sheer numbers explain the reluctance of donors to extend their commitments to any more people in need of treatment.

Whatever their reasons , the fact remains that it is new patients who are most at risk of dying. If we are to help them, and address this disastrous public health crisis, then donors need to honour their commitments and continue funding treatment for everyone who needs it. This is no time to quit.

Dr Mit Philips is health policy analyst for Médecins Sans Frontières.