- 30% of critical, first-line TB #medicines are substandard - underdosed, degraded, or just plain #counterfeit
- The 10% of African TB cases that are drug-resistant due to underdosed pills would each cost $15,000 to treat #suberbug
- In #Africa don't blame patient negligence as the cause for resistant TB cases
Alice Ndlovu has tuberculosis but, relatively speaking, she is one of the lucky ones. Hers is a strain that responds to the best medicines available, which also happen to be the cheapest. At 28, this single mom knows that without treatment she would likely die, leaving her child to face the orphanage in a country that already has a million orphans. “I still have six weeks’ treatment to go, but hopefully that will be the end, and I’ll be home. I will see my son grow up,” she told me at her home in a poor suburb of Cape Town.
At least a quarter of the world’s population — overwhelmingly concentrated in poorer regions of the world — is infected with TB, which generally lies dormant until the carrier’s immunity is impaired by another disease. (Often, this is HIV.) Without treatment, about half of the patients with active TB will die. According to the World Health Organization, TB claimed 1.7 million lives in 2009, most of them in Africa.
The standard treatment for TB is long and complicated: It requires that patients take antibiotic combinations, at least 15 pills per day, over a six-month period. The side effects of treatment are unpleasant, including fever, vomiting, jaundice, and blurred vision. If treatment is stopped too soon or skipped, the bacteria that are still alive can become resistant, leading to a form of TB that is much more dangerous and difficult to treat. And in malnourished or weak patients, drug-resistant strains of TB can quickly become fatal.
"But while TB is less acutely fatal than malaria, this actually makes the resistance problem of underdosed TB drugs more significant."
Resistance-driven drug failure is largely due to patient noncompliance with the regimen prescribed. When patients start to feel better, they often stop taking the medicine before the TB is completely overwhelmed by the drug. As a result, the still-living strain develops resistance. This problem is not unique to the developing world. In fact, the same process is the primary reason that Western health-care systems are plagued by “superbugs.” But in Africa, inconsistent drug availability and inferior drugs that fail even when the patient completes the course of treatment compound widespread patient negligence.
Over the past few years, my research team has sampled the critical first-line TB medicines, Rifampicin and Isoniazid, from a dozen African and Asian cities. In the worst locations, such as the Congo, up to 30 percent of all TB drugs are substandard, with an average of about 8 percent across poorer markets. The drugs were underdosed in some way — some were falsified products, being passed off as something they were not, others were degraded due to poor storage. But the largest problem is sloppily made drugs, made by legal manufacturers in Africa, China, and (to a lesser extent) India. These underdosed drugs are harming patients and building drug resistance.
Aside from the health burden, the financial cost of treating TB is astounding. The total drug cost for the cheapest treatment is about $60, which is reasonable even for the poor in many countries. But treatment for resistant cases consists of a bigger range of less-effective drugs with more severe side effects for a period of two years, most of it spent in the hospital. This treatment costs no less than $15,000.
This cost is a critical factor and it limits treatment options. In 2006, patients in the Tugela Ferry area of KwaZulu-Natal, South Africa, who had not previously been treated for TB were diagnosed as being infected by an extremely resistant strain. Of the 53 patients admitted for hospital treatment, 52 died. More recent outbreaks of resistant TB in South Africa have claimed the lives of two-thirds of those infected. Generally, patients are kept in isolation and treated with medications that fail most of the time; as a result, most patients infected with extremely drug-resistant TB die.
Those fighting TB could learn from those fighting malaria. The anti-malaria community started paying attention to the dangers of fake and substandard drugs a while ago — primarily as a result of the work of malaria-drug experts such as Paul Newton and Nick White, both professors at Oxford University. The anti-TB community has lagged behind.
Perhaps this is understandable — an underdosed malaria medicine means that a child may die in 48 hours, whereas an underdosed TB medicine may have no immediate impact on the patient. But while TB is less acutely fatal than malaria, this actually makes the resistance problem of underdosed TB drugs more significant. One bad treatment batch leading to ten underdosed days can lower the TB patient’s chances of a successful treatment outcome, which relies upon total elimination of the bacteria. It may also extend the required treatment time, increasing both costs and risk of resistance.
Already at least 10 percent of TB cases in Africa are resistant to the cheapest drugs, Rifampicin and Isoniazid. The underdosed drugs my team found means this percentage is set to rise. In order to preserve the efficacy of current first-line treatments as long as possible, it is absolutely vital that bad versions of these drugs are sought out by drug regulators and removed before they reach patients.
Most of the TB-policy community is focused on ensuring that low-cost TB drugs from India can be accessed by the poor. This is important. After all, interrupted treatment due to inability to pay for drugs may be as damaging for the patient and as conducive to the proliferation of drug-resistant strains as underdosed drugs. But we mustn’t render the two problems as antagonistic to one another. Dr. Simon de Villiers, a 37-year-old physician who treats TB at homes in the rural areas of the Eastern Cape, told me: “We must tackle both problems simultaneously with whatever weapons we have available.” While we don’t, and the access arguments trump quality concerns, we may increase patient access to TB drugs only to discover that too many of those drugs do not work as anticipated. Increasing resistance, cost, and fatalities will be the tragic result.
Dr. Roger Bate is a fellow at the American Enterprise Institute, his book Phake: The Deadly World of Falsified and Substandard Medicines will be published by Rowman and Littlefield in March