“Health tourists” flocking to south Asia have carried a new class of antibiotic-resistant superbugs to Britain, researchers reported on Wednesday, warning that the bacteria could spread worldwide.
Many hospital infections that were already difficult to treat have become even more impervious to drugs due to a recently discovered gene that can jump across different species of bacteria.
This so called NDM-1 gene was first identified last year by Cardiff University’s Timothy Walsh in two types of bacteria — Klebsiella pneumoniae and Escherichia coli — in a Swedish patient admitted to a hospital in India. NDM-1 stands for New Delhi metallo-betalactamase-1.
Worryingly, the new NDM-1 bacteria are resistant even to carbapenems, a group of antibiotics often reserved as a last resort for emergency treatment for multi-drug resistant bugs.
Researchers said the bugs had been brought into Britain by patients who travelled to India or Pakistan for cosmetic surgery.
“If these infections were allowed to continue without appropriate treatment, then certainly one would expect to see some sort of mortality,” Dr. Walsh, a microbiology professor, told BBC radio.
“It’s going to be very difficult to treat the infections once the patients present with these types of bacteria. You won’t get well.”
In the new study, led by Dr. Walsh and Madras University’s Karthikeyan Kumarasamy, researchers set out to determine how common the NDM-1 producing bacteria were in South Asia and Britain, where several cases had turned up.
Checking hospital patients with suspect symptoms, they found 44 cases (1.5 per cent) of those screened in Chennai, and 26 (8 per cent) of those screened in Haryana.
They likewise found the superbug in Bangladesh and Pakistan, as well as 37 cases in Britain.
“India also provides cosmetic surgery for other Europeans and Americans, and it is likely that NDM-1 will spread worldwide,” said the study, published in The Lancet.
NDM-1 was mostly found in E. coli, a common source of community-acquired urinary tract infections, and K. pneumoniae, and was impervious to all antibiotics except two — tigecycline and colistin.
In some cases, even these drugs did not beat back the infection. “We’ve actually almost run out of antibiotics. We only have two left and one isn’t particularly good,” Dr. Walsh told the BBC.
Alarming potential to spread
Crucially, the NDM-1 gene can be easily copied and transferred between bacteria. “Unprecedented air travel and migration allow bacterial plasmids and clones to be transported rapidly between countries and continents,” they said, adding that most could remain undetected.
The emergence of these new drug-resistant strains could become a serious global public health problem as the major threat shifts toward a broad class of bacteria — including those armed with the NDM-1 gene — known as “Gram-negative”, the researchers warn.
“There are few new anti-Gram-negative antibiotics in development, and none that are effective against NDM-1,” the study said.
“We believe it’s present within the community within India, not just within the hospitals,” he said.
“There are no new antibiotics that are going to be available in 10 years’ time,” Dr. Walsh said.
“There is a desperate need for new and novel antibiotics targeted towards these types of bacteria.”
Hasan Suroor adds from London
A new superbug called NDM-1, resistant to nearly all antibiotics, has been found in British hospitals and is reported to be spreading rapidly, sparking worldwide alarm.
Media reports said that up to 50 cases had already been reported, mostly involving people who had travelled to the Indian subcontinent for cancer treatment, cosmetic surgery or transplants. Some cases were also reported to have been detected in India, Pakistan and Bangladesh.
Experts said the bug which caused urinary and respiratory problems had been found resistant to one of the most powerful groups of antibiotics — Carbapenem, generally used in emergencies. Researchers, writing in the journal The Lancet Infectious Diseases, said NDM-1 had an “alarming potential to spread and diversify”.
“The potential for wider international spread are clear and frightening,” said Prof. Timothy Walsh of Cardiff University and a co-author of the research.
His fellow-researcher David Livermore of Britain’s Health Protection Agency (HPA) warned that there was a very real threat that it could become a serious global health problem.
“There have been a number of small clusters within the U.K., but far and away the greater number of cases appear to be associated with travel and hospital treatment in the Indian subcontinent. This type of resistance has become quite widespread there. The fear would be that it gets into a strain of bacteria that is very good at being transmitted between patients,” he said.
The Department of Health already put out an alert emphasising that it issued such alerts “very sparingly when we see new and disturbing resistance”.
The BBC quoted experts as saying that NDM-1 could now jump to other strains of bacteria that were already resistant to many other antibiotics.
“Ultimately, this could produce dangerous infections that would spread rapidly from person to person and be almost impossible to treat,” it said, adding that infections had already been passed from patient to patient in British hospitals.
Some of those affected by the bug were reported to be seriously ill and some were found to suffer from blood poisoning.