It's a superbug that is resistant to antibiotics -- and it may be spreading more rapidly than previously thought.
This according to a new study published in the journal Proceedings of the National Academy of Sciences.
Experts say this family of superbugs - carbapenem-resistant Enterobacteriaceae or CRE - may be spreading without symptoms - so people can spread the germs without even becoming sick themselves.
CRE is resistant to most antibiotics; strains of CRE have specific enzymes that can break down carbapenem antibiotics.
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It is mainly spread in hospitals and long-term care facilities, and experts say new ways need to be developed to prevent this type of infection.
And they say when you get sick, demanding antibiotics is not always the best thing for you -- but if you do get prescribed antibiotics... always take the full course.
And make sure the people taking care of you are washing their hands and keeping the equipment clean.
According to the CDC, CRE causes 9,300 infections and 600 deaths each year in the United States.