AT LEAST 150 years have passed since an Edinburgh doctor called Alexander Wood and the French surgeon Charles Gabriel Pravaz independently hit on the idea of using hollow, pointed needles to inject medicines. Over that time the hypodermic syringe has become both saint and sinner, symbolising life-saving vaccinations on the one hand and the miseries of intravenous drug addiction on the other. But the latest charge against the hypodermic syringe marks a new low. Is it really to blame for Africa鈥檚 AIDS pandemic?
The moment last week鈥檚 explosive study was published, critics queued up to pour cold water on its central claim that dirty needles, not unsafe sex, are the main cause of HIV鈥檚 rapid spread in Africa. To say the conclusion is heretical is to put it mildly.
The accepted view is that sexual activity accounts for around 90 per cent of the spread of HIV in Africa and dirty needles just 5 per cent, with blood transfusions and mother-to-baby infections making up the rest. But in three papers in the International Journal of STD & AIDS (vol 14, p 148), an international team has re-analysed previously published figures and trends, and concludes that unsafe sex is to blame for no more than one-third of HIV infections while dirty needles account for up to half. Promiscuity, say the authors, has been played up as a risk factor because of the West鈥檚 preconceptions about African sexuality; dirty needles have been played down for fear that people might lose trust in healthcare and immunisations.
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The two views are wildly, bewilderingly different. Many Africans will be left wondering what they should now do to stay free of HIV: avoid visiting the doctor, carry on wearing the condoms, or both? And many relief agencies must be wondering whether at least some of the money spent on condoms and safe sex education over the years might have been better used to supply clean syringes. With an effective vaccine still many years away, the implications for the future of AIDS prevention couldn鈥檛 be more serious. So where does the balance of the evidence actually lie?
The orthodox view, that dirty needles cause few HIV infections, comes from a theoretical estimate. Essentially it is based on the likelihood of people being exposed to unclean injections multiplied by the likelihood of actually catching HIV from a jab. The heretical 50 per cent figure was partly reached by looking at real injection data in studies of infected people and partly by estimating an upper limit on the number of HIV infections caused by heterosexual sex, mother-to-baby transmissions and all other possible sources.
Uncertainties abound in both approaches and neither seems able to handle all the facts. The orthodox camp in particular has a hard job explaining why in many African countries, HIV has spread so fast among heterosexuals and in patterns at odds with those seen for other sexually transmitted diseases.
More research is obviously needed. But this should not be an excuse for postponing action on the ground: whether dirty needles account for 5 per cent of Africa鈥檚 HIV infections or 50 per cent (or, as common sense would suggest, a figure in between) they are clearly exacting a terrible toll. The WHO estimates that 7.5 billion injections are given every year with dirty needles, often just rinsed in a pot of tepid water between injections. Horrifyingly, such jabs account for a third of all hepatitis B infections 鈥� more than 20 million a year. And in many countries in Africa and Asia nearly half of all injections are given this way.
Most are not even necessary. In many countries, patients demand injections and many doctors prescribe them even when pills would do. Education is part of the answer. So is technology. 鈥淎uto-disable鈥� syringes, which trap the piston and plug after a single use, are now being manufactured in large numbers. This year alone, UNICEF will buy hundreds of millions of these safer syringes for its childhood vaccination campaigns. Soon nearly all mass immunisation campaigns will use them. But, contrary to perceptions, vaccinations account for just a few per cent of all injections. The overwhelming majority are still given with cheaper 鈥渄isposable鈥� syringes that can be reused many times.
Changing that will require money and political will. But millions of lives could be saved in return. It is time surely to salvage the reputation of the hypodermic and let Dr Wood and Dr Pravaz rest in peace.