Few trades are as callous as the manufacture and distribution of counterfeit medicines for curable but life-threatening diseases such as malaria.
 

Reliable statistics about the scale of the problem are unavailable, but counterfeit drugs are thought by the World Health Organisation (WHO) to constitute between 25 and 50 per cent of the medicine supply in less developed countries.
 

The global trade in bogus pharmaceuticals will be worth some £45bn ($75bn) in 2010, according to the US-based Center for Medicine in the Public Interest (CMPI), an industry-backed think tank.
 

Fake antimalarial drugs are a particular problem, as the 500m cases of malaria worldwide every year make it a large, lucrative market.

Thirty per cent of WHO member states have ineffective or nonexistent drug regulation, so the manufacture and sale of fake antimalarials is relatively risk-free in many countries.
 

Paul Newton, head of the Wellcome Trust-Mahosot University Oxford Tropical Medicine Research Programme, based in Vientiane, Laos, says the human cost of the trade is almost impossible to estimate.
 

However, a significant proportion of the 1m deaths from malaria annually may be attributable to counterfeit drugs.
 

In response to the increasing sophistication and global scope of counterfeiting operations, the WHO and Interpol – the international police organisation – formed the International Medical Products Anti-Counterfeiting Taskforce (Impact) in 2006.
 

Aline Plançon, an Interpol officer at Impact, says: “The idea was to put together multidisciplinary groups and encourage co-ordinated enforcement.”
 

In January, Interpol went a step further, creating the dedicated Medical Products Counterfeiting and Pharmaceutical Crime (MPCPC) unit, headed by Ms Plançon. Several successful operations have led to arrests and seizures.
 

Operation Mamba II, which took place throughout August 2009, involved raids across Uganda, Tanzania and Kenya. The operation resulted in 83 police cases and some convictions – often hard to achieve.
 

South-east Asia was targeted in Operation Storm II, which concluded in January. Impact seized about 20m pills and made more than 30 arrests.

However, it is difficult to track counterfeit drugs to their origins. Chemical testing of tablets and analysis of pollen grains found in the pills and packaging have been used to trace the location of manufacturers.
 

“We know there are criminal connections between Africa and Asia, and are working to identify exact source sites, but there is more work to be done,” says Ms Plançon. Dr Newton thinks the majority of fakes originate in Asia and are shipped to Africa for sale.
 

Seized counterfeit antimalarials range from benign tablets composed entirely of flour to dangerous mixtures of toxic substances.
 

Some samples actually contain the correct active ingredients, probably in an attempt to evade detection. They are, however, often present in very low quantities. This not only undermines treatment, but could contribute to the development of resistance, rendering the medicines useless.
 

Malaria is now frequently treated with derivatives of artemisinin, a chemical from wormwood plants. Artesunate, a semi-synthetic artemisinin derivative, was the first such drug, developed in the 1970s in China.
 

The WHO now recommends administering artesunate in combination with other antimalarials, known as artemisinin-based combination therapy (ACT).
 

These drugs have become a target for criminals, as demand is high, and they are relatively expensive. In 2008, counterfeit ACTs were estimated to account for between 33 and 53 per cent of samples in mainland south-east Asia.
 

Although south-east Asia is likely to be the main manufacturing base for fake antimalarials, the problem is global. Counterfeiting operations have become big business in Africa, India and Latin America.
 

Large shipments of counterfeited ACTs were seized recently in six African countries. “Everywhere we looked, we found counterfeit medicines,” says Ms Plançon.
 

Despite Impact’s successful operations and ongoing efforts to tackle the trade, George Jagoe, of the Medicines for Malaria Venture – a not-for-profit public-private partnership aiming to tackle the disease – says the dearth of reliable data makes it impossible to judge whether the situation is improving.
 

Dr Newton agrees, describing the available statistical evidence as “meagre”.
 

Mr Jagoe suggests that the problem could be tackled by introducing more sophisticated tracking of legitimate drugs, increasing public awareness of the problem and reducing the costs of medicines.
 

There is hope: the ACT Consortium, funded by the Bill & Melinda Gates Foundation, is working to improve access to ACTs for all those suffering from malaria in less developed countries. If ACTs become cheap and readily available, the counterfeiters may find themselves out of business.