Health officials in the United States have once again warned people about the presence of an antibiotic-resistant germ that apparently had its origins in India and has now reportedly affected some people in North America.

Scientists at the U.S. Centers for Disease Control and Prevention say that the new strain of bacteria is a close variant of a similar one that has been present in the United States for several years. These germs are known to produce a substance that makes people resistant to a group of antibiotics called Carbapenems that comprises penicillin and ampicillin.

Dr. Alexander K. Kallen of the CDC's Healthcare Quality Promotion cell says the new bacteria, called New Delhi metallo-beta-caltamase NDM-1, are not an uncommon occurrence in the United States as the local version has existed for several years now.

Healthcare authorities reported no death from the Indian variant of the bacteria but warn that additional attention needs to be given to this new strain to understand how it will react in the future. In the U.S., the carbapenem-resistant bacteria is transmitted at healthcare facilities and spread through touch.

The researchers say that the NDM-1 produces a new strain of bacteria that looks similar to strain found in the US, but with an increased resistance to the drug family represented by carbapenem.

The CDC has reported three cases of this virus in the states of Massachusetts, California and Illinois, though expert opinion remains divided about its seriousness, given that nobody has died of this infection. Some studies have found that the death rate from the US variant could be as high as 40 percent, Dr. Kallen says.