Since 1998 the serious public health problem in South East Asia of counterfeit artesunate, containing no or subtherapeutic amounts of the active antimalarial ingredient, has led to deaths from untreated malaria, reduced confidence in this vital drug, large economic losses for the legitimate manufacturers, and concerns that artemisinin resistance might be engendered.
Methods and Findings
With evidence of a deteriorating situation, a group of police, criminal analysts, chemists, palynologists, and health workers collaborated to determine the source of these counterfeits under the auspices of the International Criminal Police Organization (INTERPOL) and the Western Pacific World Health Organization Regional Office. A total of 391 samples of genuine and counterfeit artesunate collected in Vietnam (75), Cambodia (48), Lao PDR (115), Myanmar (Burma) (137) and the Thai/Myanmar border (16), were available for analysis. Sixteen different fake hologram types were identified. High-performance liquid chromatography and/or mass spectrometry confirmed that all specimens thought to be counterfeit (195/391, 49.9%) on the basis of packaging contained no or small quantities of artesunate (up to 12 mg per tablet as opposed to ∼ 50 mg per genuine tablet). Chemical analysis demonstrated a wide diversity of wrong active ingredients, including banned pharmaceuticals, such as metamizole, and safrole, a carcinogen, and raw material for manufacture of methylenedioxymethamphetamine (‘ecstasy'). Evidence from chemical, mineralogical, biological, and packaging analysis suggested that at least some of the counterfeits were manufactured in southeast People's Republic of China. This evidence prompted the Chinese Government to act quickly against the criminal traders with arrests and seizures.
An international multi-disciplinary group obtained evidence that some of the counterfeit artesunate was manufactured in China, and this prompted a criminal investigation. International cross-disciplinary collaborations may be appropriate in the investigation of other serious counterfeit medicine public health problems elsewhere, but strengthening of international collaborations and forensic and drug regulatory authority capacity will be required.
Paul Newton and colleagues' international, collaborative study found evidence that counterfeit artesunate was being manufactured in China, which prompted a criminal investigation.
Malaria is one of the world's largest public health problems, causing around 500 million cases of illness and at least one million deaths per year (the estimates vary widely). The most serious form of malaria is caused by the parasite Plasmodium falciparum, which has become resistant to multiple drugs that had previously been the cornerstones of antimalarial regimens. One group of drugs for treating malaria, the artemisinin therapies including artesunate, are based upon a Chinese herb called qinghaosu; these have now become vital to the treatment of P. falciparum malaria. But counterfeit artesunate, containing none or too little (“subtherapeutic levels”) of the active ingredient, is a growing problem especially in South and East Asia. Fake artesunate is devastating for malaria control: it causes avoidable death, reduces confidence in the drug, and takes away profit from legitimate manufacturers. Of major concern also is the potential for subtherapeutic counterfeit artesunate to fuel the parasite's resistance to the artemisinin group of drugs.
Previous estimates have suggested that between 33% and 53% of artesunate tablets in mainland South East Asia are counterfeit. In this paper the authors report on an unprecedented international collaboration and criminal investigation that attempted to quantify and source counterfeit artesunate among some of the most malarious countries in Asia.
Why Was This Study Done?
Previous reports have identified the problem of fake artesunate, but as of yet there have been few reports on the potential solutions. Concerned health workers and scientists, the regional World Health Organization (WHO) office and the International Criminal Police Organization (INTERPOL) got together to discuss what could be done in May 2005 when it became clear the counterfeit artesunate situation was worsening in the Greater Mekong Sub-Region of South East Asia (comprising Cambodia, Lao People's Democratic Republic, Myanmar, Thailand, Vietnam, and Yunnan Province in the People's Republic of China). Their subsequent investigation combined the goals and methods of a range of concerned parties—police, scientists, and health workers—to identify the source of counterfeit artesunate in South East Asia and to supply the evidence to help arrest and prosecute the perpetrators.
What Did the Researchers Do and Find?
The researchers conducted forensic analyses of samples of genuine and counterfeit artesunate. They selected these samples from larger surveys and investigations that had been conducted in the region beginning in the year 2000. Genuine samples were supplied by a manufacturer to provide a comparator. The authors examined the physical appearance of the packages and subjected the tablets to a wide range of chemical and biological tests that allowed an analysis of the components contained in the tablets.
When comparing the collected packages and tablets against the genuine samples, the researchers found considerable diversity of fake artesunate in SE Asia. Sixteen different fake hologram types (the stickers contained on packages meant to identify them as genuine) were found. Chemical analysis revealed that all tablets thought to be fake contained no or very small quantities of artesunate. Other ingredients found in the artesunate counterfeit tablets included paracetamol, antibiotics, older antimalarial drugs, and a range of minerals, and there were a variety of gases surrounding the tablets inside the packaging. Biological analyses of pollen grains inside the packaging suggested that the packages originated in the parts of South East Asia along the Chinese border.
What Do these Findings Mean?
The results were crucial in helping the authorities establish the origin of the fake artesunate. For example, the authors identified two regional clusters where the counterfeit tablets appeared to be coming from, thus flagging a potential manufacturing site or distribution network. The presence of wrong active pharmaceutical ingredients (such as the older antimalarial drugs) suggested the counterfeiters had access to a variety of active pharmaceutical ingredients. The presence of safrole, a precursor to the illicit drug ecstasy, suggested the counterfeits may be coming from factories that manufacture ecstasy. And the identification of minerals indigenous to certain regions also helped identify the counterfeits' origin. The researchers concluded that at least some of the counterfeit artesunate was coming from southern China. The Secretary General of INTERPOL presented the findings to the Chinese government, which then carried out a criminal investigation and arrested individuals alleged to have produced and distributed the counterfeit artesunate.
The collaboration between police, public health workers and scientists on combating fake artesunate is unique, and provides a model for others to follow. However, the authors note that substantial capacity in forensic analysis and the infrastructure to support collaborations between these different disciplines are needed.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050032.
The World Health Organization in 2006 created IMPACT—International Medical Products Anti-Counterfeiting Taskforce—with the aim of forging international collaboration to seek global solutions to this global challenge and in raising awareness of the dangers of counterfeit medical products. The task force membership includes international organizations, nongovernmental organizations, enforcement agencies, pharmaceutical manufacturers' associations, and drug and regulatory authorities. IMPACT's Web site notes that trade in counterfeit medicines is widespread and affects both developed and developing countries but is more prevalent in countries that have weak drug regulatory systems, poor supply of basic medicines, unregulated markets, high drug prices and/or significant price differentials. IMPACT holds international conferences and maintains a rapid alert system for counterfeit drugs.
The drug industry's anticounterfeit organization, Pharmaceutical Security Institute, works to develop improved systems to identify the extent of the counterfeiting problem and to assist in coordinating international inquiries. Its membership includes 21 large pharmaceutical companies.
The Web site of David Pizzanelli, a world expert on security holography, contains a PowerPoint presentation co-authored by Paul Newton that illustrates the different types of fake holograms found on fake artesunate packages, and their implications for artemisinin resistance (http://www.pizzanelli.co.uk/content/artesunate.html).