28 Oct 2010

Drug resistant superbug threatens UK hospitals

Efforts to contain a new strain of superbug threatening the NHS and other health authorities around the world may almost be unachievable, exclusive research by Channel 4 News reveals.

The bacteria, which has been linked to patients treated in hospitals in the Indian sub-continent, is resistant to nearly all antibiotics. Though first only found in patients being treated in hospital – we’ve found evidence that it may be widespread in the community in India and potentially elsewhere.

There have been 64 cases of the superbug in the UK and five people have died while infected. Since it was first identified in 2007 patients infected with the bacteria have now been found in 16 countries worldwide.

“The number of cases we’ve seen in the UK is quite small,” said Dr David Livermore, director of the antibiotic resistance monitoring laboratory at the UK’s Health Protection Agency in London.

“But we are importing bacteria with this type of resistance particularly from the Indian sub-continent – and when you look at population flows, it looks likely we will continue to import more and more.”

“The fear has to be they will get traction within UK hospitals and they start to spread from patient to patient in the UK,” Dr Livermore added.

NDM-1

The threat is from bacteria carrying a type of antibiotic resistance called NDM-1. It’s the scientific shorthand for an enzyme that allows bacteria to break down some of the most powerful antibiotics used to treat life-threatening infections in hospitals.

The enzyme has been found in common bacteria like E.coli, a cause of routine infections after surgery or procedures like kidney dialysis. Normally these infections are simple to treat with antibiotics – but if the bacteria are carrying NDM-1 they are almost impossible to kill.

I am ashamed of the government’s reaction. Dr Jayanta Sarma

Only two antibiotics can kill NDM-1 bacteria. One is toxic so doctors only use it in extreme cases. The other cannot be used to treat urinary tract infections – one of the most common infections caused by E.coli and therefore useless against this type of NDM-1 infection.

There are other forms of antibiotic resistant bacteria like MRSA and C. difficile against which drugs are becoming useless. But NDM-1 worries experts more. The gene for the enzyme can be passed from bacteria to bacteria so it has the potential to lead to scores of new species of superbugs.

Political interference

A team of British and Indian scientists published a paper in the Lancet Infectious Diseases medical journal earlier this year, linking the superbug to medical tourism to India and Pakistan.

Our investigation has found that further collaboration between Indian and British scientists was halted, after direct intervention by Indian health authorities. Many doctors in India voiced anger that the report would damage a burgeoning medical tourism industry in India.

Channel 4 News has obtained a copy of a letter from the Indian health ministry sent to Indian scientists who collaborated on the Lancet Infectious Diseases report. It challenges the researchers, suggesting that they broke the law by sending samples of bacteria overseas as part of the study.

None of the scientists we contacted in India would talk to us about the research, however one of them Dr Jayanta Sarma is now back in the UK working for the NHS in Northumberland.

“As and Indian, I am ashamed of the government’s reaction,” Dr Sarma said. “We need to do studies in the community [in India] to find out how far this superbug has spread to the population and what the danger is to the rest of the world.”

Collating samples

None of the Indian researchers who worked on the Lancet Infectious Diseases study wanted to continue their collaboration with researchers here. So under the guidance of the lead author of the study, Dr Tim Walsh at the University of Cardiff, Channel 4 News conducted a study he and his Indian collaborators had wanted to carry out: collecting samples of water from sewers around New Delhi.

The finding is interesting, and disturbing. Dr David Livermore

Out of more than 120 sites across the city, we found 11 samples containing NDM-1 bacteria. The study only provides a crude snapshot of the presence of the bacteria outside hospitals, but it suggests NDM-1 in gut bacteria like E.coli may be widespread in people in Indian cities and perhaps elsewhere.

“It suggests NDM is spread all over Delhi and people are carrying [these bacteria] as part of their normal flora,” said Professor Walsh.

Scientists warn against new superbug threat

Evidence that the superbug is present outside hospitals means that efforts to contain it – which have been partially successful for bugs like MRSA – may fail. However hard hospitals try to contain infections, they will be continually reintroduced from people bringing the infection into the hospital with them.

“The finding is interesting, and disturbing,” said Dr Livermore. “It implies that control will be harder than if this was just a hospital acquired infection.”

Though it is likely healthy people travelling to and from India may be carrying NDM-1bacteria with them, Dr Livermore suspects it’s not yet widespread in the UK or other countries with better levels of sanitation. “It’s important to remember, nearly all the cases we have seen so far in the UK have been linked to hospital treatment,” he said.

Antibiotic mis-use

While NDM1 may have originated anywhere in the world, many experts think the widespread mis-use of antibiotics, poor sanitation and a rapidly expanding medical sector on the Indian subcontinent has led to the rise of the superbug there.

Though India has tough laws on antibiotic prescribing, many go unheeded. “A lot of antibiotic resistance in India is do the mis-use or overuse of antibiotics,” said Dr Randeep Guleria, professor of medicine at the All India Institute of Medical Sciences in New Delhi.

Antibiotics are available without prescription from high street pharmacies and their overuse exposes more and more bacteria to the drugs. In such situations, constantly dividing bacteria quickly evolve resistance to antibiotics.

Such superbugs are everywhere. They’re not a characteristic of one country. Dr V.M. Katoch

The overuse of powerful “last-resort” antibiotics in hospitals is blamed on the rise of superbugs like MRSA in Europe and the US. Indian health experts worry similar practices in India has led to the rise of bacteria like NDM-1.

Dr V.M. Katoch, Secretary of the Indian Department of Health Research told Channel 4 News that he was unaware who in the Health Ministry had sent the letter to scientists who worked on the Lancet Infectious Diseases study.

But he felt the research unfairly singled out India given that other countries, including the UK, are struggling to control antibiotic resistance. “Such superbugs are everywhere. They’re not a characteristic of one country,” he said.

Dr Katoch also denied that India was the epicentre of the NDM1 superbug. “NDM1 originated in the environment,” he told Channel 4 News. “India has a problem, but India has the same problem other countries do.”

The emergence and spread of NDM1 highlights a growing problem of antibiotic resistance worldwide and the dwindling arsenal of drugs to treat infections. In the last decade researchers have only produced a handful of new antibiotics.

“Against some bacteria like MRSA, were getting new antibiotics,” says Dr Livermore. “But bacteria like those with NDM1-type resistance, I’m afraid the bacteria are winning. They’re accumulating resistance faster than we’re developing new drugs.”

Many experts believe the threat of antibiotic resistance to modern medicine is so grave a global effort is needed to stop their spread and develop new drugs.