The bacteria possess the New Delhi metallo beta lactamase gene that makes them resistant to most known antibiotics. Medical studies suggest that NDM-1 has circulated in India since 2006 and patients visiting India have carried the bacteria to other countries.
“This is Canada’s first local acquisition of an organism previously linked to travel to the Indian subcontinent,” said Susan Poutanen, a microbiologist at the Mount Sinai Hospital in Toronto. “We don’t know the source, but the case suggests that NDM-1, which has mainly been linked to hospital stays in India, no longer necessarily has to have that link,” Poutanen told The Telegraph in a telephone interview.
“The NDM-1 was picked up locally, but this is a single case — there is no evidence it is continuing to circulate here,” said Poutanen, but added that the case has underlined the need for heightened surveillance for NDM-1.
Studies over the past year revealing the presence of NDM-1 bacteria in several cities and in environmental water samples in India have stirred controversy with the health ministry claiming the findings have no public health significance.
Microbiologists believe the widespread abuse of antibiotics across India has provided an environment conducive for the emergence of NDM-1. The health ministry, they said, has tried to play down the threat posed by NDM-1.
“We know that NDM-1 is found in the environment, in the water supply in India — so even with just a short visit to India, there is a considerable chance someone will pick up NDM-1 containing bacteria,” said Mark Toleman, a microbiologist at Cardiff University who had published a paper in the journal Lancet earlier this year reporting the presence of NDM-1 bacteria in water samples.
Researchers point out that although NDM-1 has been found in more than 20 countries worldwide, in the vast majority of cases, the patients have had a previous direct link to India — either a hospitalisation or a visit to India, Pakistan or Bangladesh.
Poutanen and her colleagues have also isolated NDM-1 bacteria from a 71-year-old woman who had travelled to India in September 2010 for a medical procedure and had stayed in a hospital in New Delhi for 10 days.
Three days after returning to Toronto, she developed a fever and tests revealed that she had NDM-1 bacteria. Three months after those investigations, urine tests from the patient continued to show NDM-1 bacteria, the doctors reported.
Researchers believe bacteria have acquired the NDM-1 gene from as yet unidentified micro-organisms. “It is possible for this to happen anywhere, but the chances are much, much, much more likely in a country that mass produces antibiotics, systematically abuses them, and has almost no controls on their use,” Toleman told The Telegraph.
Some countries have also reported import of NDM-1 from Bangladesh and Pakistan, and from Balkan countries which appear to have a small reservoir of infection. But, Toleman said, studies suggest that the problem in the Balkans may be linked to kidney transplants performed in Pakistan and imported with patients returning home.