The message is clear and simple. A country that admits the scale of the problem is the one where it is possible to stop the inexorable spread of HIV throughout the population.
Scientists at the World Health Organisation in Geneva have released their most pessimistic assessment yet of the Aids epidemic in Africa, where 21 million people are infected with the virus, two-thirds of the total in the rest of the world. The most worrying feature of this statistic is that 90 per cent of these carriers do not know they are infected, and are seemingly oblivious to their potential for passing on the virus to others.
It is sometimes easy to forget that Aids - the modern plague, as it has so often been called - is almost entirely avoidable. HIV is an infectious agent, but one that is easy to block by following simple rules about sexual abstinence or safe sex. There is no need for the difficult technological fixes required for many other infectious diseases. The answer to HIV is simple. Use a condom, or just say No.
Uganda understood this message early on and has begun, finally, to reap the benefits, albeit after the deaths of far too many of its citizens. Latest figures on infection rates in this part of central Africa show that the message of its government's brave non-denial is beginning to save lives.
For the rest of Africa, however, the outlook is extremely gloomy. The WHO's latest surveillance figures, which are by far the most accurate estimates to date, point to countries where HIV has become alarmingly endemic.
In Botswana and Zimbabwe, countries not considered to be in the original centre of the epidemic, HIV now affects more than one in four adults. In some African cities infection rates are higher than 30 per cent. The WHO says that as many as 70 per cent of women attending some African antenatal clinics are HIV-positive.
The WHO pulls no punches over the mess that Africa is in. Aids there will rival the Great Plague of the Middle Ages, which laid waste the population of Europe, and the worst influenza epidemic in history, in the winter of 1918-1919, when more than 20 million people died - more than those killed in action during the First World War.
No doubt the cynics and detractors will repeat their accusations that the WHO is cooking the books to make it seem as though it has a huge struggle on its hands, in order to lobby for extra funding. At least one Sunday newspaper in Britain has attempted, unsuccessfully, to expose the "myth" of Aids in Africa. The campaign failed largely because the sheer quality and authority of the scientific data on the spread of HIV in Africa overwhelmed the combination of anecdote and misrepresentation that the newspaper relied on.
It would, however, be impossible to ignore the latest report from the WHO's team of scientists working in the field. They now clearly detect that the epidemic has strengthened its stranglehold of central Africa, and has taken a dramatic turn south.
Countries in sub-Saharan Africa account for the world's 21 highest rates of HIV among adults aged 15 to 49 - the normal age bracket for the most sexually active members of a society. Every African country south of the Sahara now has its own home-grown epidemic, and in 13 of these HIV has infected at least 10 per cent of adults. From Mali in the north to Botswana in the south, Aids has become dangerously endemic.
There is another deadly factor in the African equation. HIV in this part of the world is almost entirely spread by heterosexual intercourse, which means that as many women as men are infected. As a result of this sexual equality, HIV in Africa has hit children harder than anywhere else in the world. Nearly nine out of every ten children in the world who are infected with HIV live in Africa, partly because infected mothers pass on the virus during pregnancy, childbirth or breast-feeding.
HIV is spread heterosexually in Africa probably because of the number of untreated venereal diseases, which cause lesions in the skin that facilitate blood-to-blood transfer of the virus.
The very young (along with the very old) have, of course, always taken the brunt of any epidemic. What makes Aids particularly dangerous in Africa is that it primarily affects the most economically important members of society: sexually active adults, who are frequently the sole supporters of the very young and the old. If they are not already worried, African governments should consider the implications of losing between 10 and 30 per cent of their able-bodied workforce within the next decade.
There are other features of HIV that make it uniquely terrifying. One is that the disease attacks the very defences the body uses to fight off disease, and in Africa a healthy immune system is more vital than in many other parts of the world, where there are fewer infectious diseases. The second is that it takes so long for HIV to cause the first symptoms. It is easy for anyone to understand that a bullet fired from a gun is dangerous. It is not so easy to comprehend a gun's lethality when its bullet takes 10 years to have any affect whatsoever on the victim.
There are also unique features of African countries which make them particularly prone to HIV. For a start, the virus has been on the continent longer than it has existed anywhere else. As a result it has managed to evolve into many different sub-types, all of which are present in Africa, and can pose different problems for the body's immune defences.
African societies are also conducive to the spread of Aids. There are low levels of literacy which make public education difficult. There is war, famine, poverty and a history of migrant labour, all of which create the conditions for the mass movement of people and the creation of a thriving sex industry that helps HIV to spread.
But all is not lost for Africa, providing other countries follow the example of Uganda. Against a background of almost universal denial by the rest of the continent, Uganda was the first to admit that it had a problem. Its government responded with an active national campaign, much like those in Britain and elsewhere, where the simple facts of HIV and Aids gradually replaced the fear and ignorance that have so often helped the virus to spread elsewhere in the world.
Uganda established active prevention programmes, which focused on delaying sexual relations for adolescents and negotiating safe sex with an insistent partner. Ugandans between the ages of 15 and 19 - the latest recruits to sexual activity - are half as likely to be infected with HIV as people five years older.
This is important because the 15-19 age group is the "engine" of any Aids epidemic, and falling infection rates in these youngsters suggest a long-term decline in the numbers contracting Aids. This, of course, will turn out to be the case only if the message continues to get through to adolescents before they start having sex.
Scientists working in Uganda say that one of the biggest influences on young people was seeing what had happened to their older brothers and sisters who had led a promiscuous adolescence: they died. Sex did not then look such an attractive proposition.
Being open and honest about the message of Aids is as strong now as it was when those slick advertisements warned Britons not to die of ignorance. If it can work in Uganda, it can work anywhere.Reuse content