MORE than eight million people get sick with tuberculosis every year, according to the World Health Organization. In 2011, 1.4 million died from it, making it the world's deadliest infectious disease after AIDS. Thanks to billions of dollars spent on diagnosis and treatment over the past decade, deaths and infections are slowly declining. Yet a disturbing phenomenon has emerged that could not only reverse any gains we've made, but also encourage the spread of a newly resistant form of the disease.
In the largest study of its kind, to be published today in the International Journal of Tuberculosis and Lung Disease, colleagues and I have found that fake and poorly made antibiotics are being widely used to treat tuberculosis. These substandard drugs are almost certainly making the disease more resistant to drugs, posing a grave health threat to communities around the world.
Our research team collected samples of two commonly used medicines, isoniazid and rifampicin, from neighborhood pharmacies and markets in 17 countries where tuberculosis is pervasive across Africa, Asia, South America and Europe. Nearly one of every 10 pills we collected failed to meet basic quality standards. In African countries, one in six pills was substandard.
Failing pills typically had too little of the active ingredient — the molecule that destroys tuberculosis bacteria. Most of these drugs came from legitimate manufacturers; they were either poorly made or corroded in transit. The rest appeared genuine, but after researchers tested them and more closely analyzed the packaging, they turned out to be fakes — produced and distributed through criminal enterprises. A pack of fake pills might sell for a dollar on the streets of India, but estimates of the global market for fake drugs range into the tens of billions of dollars.
The World Health Organization recommends that tuberculosis patients receive supervised treatment and quality medicines provided by public health departments. But traveling to the clinics where this treatment is dispensed can be very expensive, especially for poorer patients. Private markets for tuberculosis drugs — where we procured our samples — are often easier to access. For patients in Zambia, for example, treatment through the national tuberculosis program is three times more expensive than self-administering treatment with drugs purchased at local markets. In addition, counterfeiters in emerging markets can infiltrate the legitimate supply chain by submitting falsified paperwork and lying about where the drugs originated. When this happens, most pharmacists have no idea that the products they sell won't work.
Some patients will die outright when shoddy medicines fail to cure them. Others will take drugs with too little active ingredient, killing some of their infection's bacteria but leaving the strongest to multiply. These patients could go on to spread a drug-resistant form of the disease, which is deadlier and vastly more expensive to control.
Back in the 1990s, New York City spent more than $1 billion on an epidemic of drug-resistant tuberculosis. Today, curing a single case of it in the United States can cost more than $200,000. The financial and public health risks for Americans are so great that the Department of Homeland Security has called the most lethal known form of the disease, an extremely drug-resistant tuberculosis called XDR-TB, an "emerging threat to the homeland." Virtually unknown 10 years ago, XDR-TB has now been identified in at least 77 countries — including the United States.
The Food and Drug Administration recently approved a drug called Sirturo, designed to target drug-resistant forms of the disease. While this provides a welcome new hope, we fear it will not be enough. Tuberculosis will not be brought under control until we reduce patients' exposure to substandard medicines.
This is not a problem for just the developing world. While stronger manufacturing practices, more effective regulatory agencies and more alert customs officials help protect the supply here, the United States is not impervious to bad drugs. Last fall, a generic version of Lipitor produced in India was recalled after it was found to contain particles of glass. Since the United States is currently facing a shortage of tuberculosis medicines, it will look to sources outside the country. It must ensure that these drugs are of sufficient quality.
The United States Centers for Disease Control and Prevention is best positioned to lead the fight against substandard and fraudulent tuberculosis drugs. The agency works with public health organizations around the world to stop health threats before they reach our shores. And it is run by Dr. Tom Frieden, who led New York City's successful campaign against drug-resistant tuberculosis in the '90s. The C.D.C. should work with the State Department's new Office of Global Health Diplomacy and the World Bank to help foreign governments, law enforcement agencies and pharmaceutical companies strengthen drug supply chains and prevent companies from making substandard products.
They should follow the lead of the President's Malaria Initiative, which tests every batch of drugs it provides to patients in poor countries, and encourage authorities to do the same for tuberculosis drugs. Drug regulators should also confirm that available medicines are really registered where they say they are (we found that unregistered medicines were more likely to be substandard). Finally, they must prosecute and imprison makers of lethal fake drugs.
As long as substandard tuberculosis drugs are permitted in the marketplace, people will continue to die in pursuit of a cure. And without a coordinated response, growing resistance will eventually render even the highest quality drugs obsolete.
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