REXBURG, Idaho -

Respiratory syncytial virus, or RSV, has reached Rexburg.

Two confirmed cases of RSV at Madison Memorial Hospital have prompted officials to ban visitors under the age of 18 or ones with flu-like symptoms.

RSV is essentially a really bad cold, but in patients less than 2 years old and the elderly, the effects can be far worse.

"With even just two positive cases, RSV is so highly contagious that we just felt like that there was a large risk for an epidemic. There could be more additional cases if we don't take care of the patients that we have,” said Mikel Barr, the hospital's director of quality improvement.

The hospital had to cancel an annual school field trip to the hospital that was scheduled to take place Thursday.

Doctors say one of the best things you can do to prevent the spread of RSV is to wash your hands.