A new antibiotic-resistant "superbug" has emerged in India and Pakistan and spread to British hospitals, and health professionals are warning that it could become a major problem worldwide. The bacterium has also been detected in the United States, Canada, Australia, the Netherlands and Sweden. British scientists blame the spread on medical tourism to India, often for cosmetic surgery. Scientists fear bacteria with a gene named NDM-1 (New Delhi Metallo-1) could jump to other antibiotic-resistant bacteria — most notably MRSA — and even common E.coli to create infections that would spread quickly and be nearly impossible to treat. Scientists say NDM-1 alters the bacteria, making them resistant to even the most powerful group of antibiotics, carbapenems. "There have been a number of small clusters within the UK, but far and away the greater number of cases appear to be associated with travel and hospital treatment in the Indian subcontinent," Dr. David Livermore, one of the researchers and who works for the UK's Health Protection Agency, told the BBC. "This type of resistance has become quite widespread there." Three U.S. cases of NDM-1 were identified between January and June, the Wall Street Journal writes. Te U.S. Centers for Disease Control and Prevention said the patients had received recent medical care in India. "The potential of NDM-1 to be a worldwide public health problem is great, and coordinated international surveillance is needed," the authors wrote. Researchers are also calling for new antibiotics to combat the superbug. Their report was published in The Lancet. Here are a Q&A and a map of infection hot spots. The report comes just as the CDC says MRSA may be in decline.