Bird 'flu is on the wing in Africa. It is wiping out poultry stocks in Nigeria, while neighbours nervously await its inevitable arrival--yet the supply of effective drugs is undermined by governments' failures that have created a plague of counterfeits.

While it is far from certain that the deadly HN51 strain of the virus will mutate into a form that can be transmitted between people, Africans are right to be uneasy about the prospect of an epidemic. The fact is that most of the weapons that exist to fight the disease will be rendered useless by the actions of criminal drugs counterfeiters and complicit officials.

Fake drugs are a booming business in many poorer parts of the world. In Nigeria and parts of China, for example, the WHO estimates that a staggering 40 to 50 per cent of all drugs in circulation are illegal copies. These counterfeits line the pockets of criminals, and possibly terrorists, and they pose a serious threat to health individuals and the ability to fight disease-eradication campaigns.

Vaccinating poultry flocks is essential to any bird 'flu strategy. In China, however, the market is flooded with fake vaccines that are, at best, useless--at worst, they strengthen resistance to the virus. So farmers who think they are protecting their flocks are unwittingly nurturing the virus. With over 14 billion chickens in China alone, that is a scary thought.

Because counterfeit drugs can make genuine branded drugs useless: containing too little of the active ingredient, they can act like an "inoculation" to the virus, bacterium or parasite they are designed to kill. They could help the bird 'flu virus mutate into new, drug-resistant, strains, rendering existing treatments useless. In the event of an avian 'flu pandemic, we really do not want the best currently existing treatment, Tamiflu, to be redundant.

This is a very real and frightening prospect: it is already happening with malaria. Counterfeiters around the world have cashed in on the massive demand for the latest and most effective anti-malarial drug, artemisinin. The pharmacies of South-East Asia are stuffed with the copies, with over half the artemisinin derivatives sold in the region containing incorrect levels of the active ingredient.

Even though this wonder drug has only been widely available since the late 1990s, scientists are already reporting cases of resistance to it. According to Dr. Dora Akunyili, the head of Nigeria's national chief drug regulator, the racket in fake medicine is directly responsible for this resistance, as well as the fact that malaria deaths have doubled in the last 20 years. In this way the the counterfeiters are threatening the lives of anyone who lives in a malarial area: over 100,000 people die each year from fake anti-malarials in South East Asia alone.

The same is true for the antiretroviral drugs used to treat HIV/AIDS sufferers: even the latest drugs are being undermined by drug-resistant forms of the HIV virus. It is only a matter of time before the same fate befalls treatments for avian 'flu, as demand for Tamiflu grows and people turn to the black market. Already the internet is awash with spurious Tamiflu, while consignments have been discovered as far apart as London, New York and Beijing.

Fake drugs can contain deadly additives, as when 119 children died in India and Haiti from cough syrup prepared with anti-freeze. Chinese newspapers report 192,000 deaths from fake drugs every year, and the number could be far higher. But China and India are the top producers of counterfeit drugs.

The reality is that governments around the world are directly responsible for the global counterfeiting plague.

Most obviously, governments stimulate demand for cheaper fakes by artificially driving up the price of legitimate drugs through a range of swingeing taxes and tariffs--while whining about the price charged by the company that researched, discovered, developed and manufactured the drug at its own risk. It cannot be a coincidence that the two countries with the highest levels of counterfeit drugs--Pakistan and Nigeria--also top the league for medicine taxes.

Manufacturers and sellers of counterfeits also thrive in countries which fail to administer their laws. When the judicial system is corrupt and the law is enforced arbitrarily, gangsters have little difficulty persuading the authorities to turn a blind eye to their nefarious activities, through bribery or intimidation. China, one of the biggest sources of fakes, has a particularly poor track record in clamping down on the racketeers.

Furthermore, a weak rule of law means that companies are unable to protect their trademarks, vital for guaranteeing to consumers the quality and origin of a product. When a fake masquerades as a legitimate drug by adopting its brand, consumers are unable to tell the difference and the counterfeiters get a free ride.

Finally, in countries with the rule of law, individuals and companies harmed by a counterfeits can are able to obtain redress in the courts. But in the majority of lower-income countries, cases can take years to progress through corrupt or weak courts.

The World Health Organisation is gathering officials and NGOs from around the world this week in Rome, to advocate "a mechanism for concerted international action against counterfeit medicinal products." But there are plenty of laws already: what is missing is the rule of law.

We can only beat the counterfeiters by strengthening and upholding the rule of law. This is not some arcane side issue. It goes right to the heart of economic failure or success. An economy will never grow without criminal and civil law, including contracts, trademarks, property rights and so on, being enforced impartially. These are the software of civil peace, development and prosperity.

The repressive and incompetent governments that do not understand this are complicit in thousands of deaths. In the event of a bird 'flu pandemic, they will be responsible for many thousands more.

Philip Stevens is Director of the Campaign for Fighting Diseases, London, an international development charity.