Alarming levels of drug-resistant tuberculosis found worldwide

The data emanating from several countries show that there is a hike in drug-resistant TB which can cost 200% more to treat.

Scientists have found an alarming number of cases of the lung disease, tuberculosis (TB), in Africa, Asia, Europe and Latin America, that are resistant to at least four powerful antibiotics.

In a large international study published in the Lancet medical journal on Thursday, researchers found rates of both multi drug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) were higher than previously thought.

The report also said the diseases are threatening global efforts to curb their spread.

“Most international recommendations for TB control have been developed for MDR-TB prevalence of up to around 5 per cent.

“Yet now we face prevalence up to 10 times higher in some places, where almost half of the patients are transmitting MDR strains,” Sven Hoffner of the Swedish Institute for Communicable Disease Control, said in a commentary on the study.

TB is already a worldwide pandemic that has infected 8.8 million people. It killed 1.4 million in 2010.

Drug-resistant TB is more difficult and costly to treat than normal TB, and is more often fatal.

MDR-TB is resistant to at least two first-line drugs – isoniazid and rifampicin – while XDR-TB is resistant to those two drugs as well as a powerful antibiotic type called a fluoroquinolone and a second-line injectable antibiotic.

Treating even normal TB is a long process, with patients needing to take a cocktail of powerful antibiotics for six months. Many patients fail to complete their treatment correctly, a factor which has fuelled a rise in the drug-resistant forms.

Researchers who studied rates of the disease in Estonia, Latvia, Peru, the Philippines, Russia, South Africa, South Korea and Thailand found almost 44 per cent of cases of MDR TB were also resistant to at least one second-line drug.

Tom Evans, chief scientific officer at Aeras, a non-profit group working to develop new TB vaccines, told Reuters that treatment options for XDR-TB patients are “limited, expensive and toxic.”

Treatments for drug-resistant TB can cost 200 times more than those for normal TB, he said in an emailed statement. They can also cause severe side effects like deafness and psychosis, and can take two years to complete, he added.

In the U.S., MDR-TB treatment can cost 250,000 dollars or more per patient, and in many poorer countries costs can be catastrophic to health systems and patients’ families.

“Without a robust pipeline of new drugs to stay one step ahead, it will be nearly impossible to treat our way out of this epidemic,” Mr. Evans said.

Tracy Dalton from the U.S. Center for Disease Control and Prevention, who led the Lancet study, said that so far, XDR-TB has been reported in 77 countries worldwide.

“As more individuals are diagnosed with, and treated for, drug-resistant TB, more resistance to second-line drugs is expected to emerge,” she said.

The spread of these drug-resistant strains is “particularly worrisome” in areas with poor healthcare resources and limited access to effective drugs, she added.

TB is a bacterial infection that destroys patients’ lung tissue, making them cough and sneeze and spread germs through the air.

Experts say anyone with active TB can easily infect another 10 to 15 people a year.

The World Health Organisation (WHO) predicts more than two million people will contract MDR TB by 2015.

A report by non-governmental organisations in March said a $1.7 billion shortfall in funds to fight TB over the next five years meant 3.4 million patients would go untreated and gains made against the disease will be reversed.

In their research, Dalton and colleagues found rates of resistance varied widely between countries.

Overall, resistance to any second-line drug was detected in nearly 44 per cent of patients, ranging from 33 per cent in Thailand to 62 per cent in Latvia.

In about a fifth of cases, they found resistance to at least one second-line injectable drug.

This ranged from two per cent in the Philippines to 47 per cent in Latvia.

XDR-TB was found in 6.7 per cent of patients overall. Rates in South Korea, 15.2 per cent, and Russia 11.3 per cent, were more than twice the WHO’s global estimate of 5.4 per cent at that time.