LOGAN -- About 100 elementary school children in Cache County have been told to stay home until further notice after four cases of whooping cough were confirmed, health officials said Friday.
The latest health threat comes on the heels of a recent measles outbreak in the Salt Lake City area that began with an unimmunized student who traveled to Poland.
Jill Parker, spokeswoman for the Bear River Health Department, said it is difficult to tell how many others are at risk of contracting whooping cough beyond the 100 unimmunized students at three schools near Logan.
But she said whooping cough, like measles, is highly contagious and exposure can occur if a person comes within 3 feet of someone who is infected.
"School is not the only place these children are in contact," Parker said. "It's soccer season, and there are band concerts going on."
The unimmunized students sent home may have to stay there for 21 days. The first case of whooping cough was confirmed April 20. Three more cases were confirmed Thursday, prompting health officials to declare an outbreak and begin notifying parents.
National health officials said whooping cough has been on the upswing since last year.
Dr. Tom Clark, medical epidemiologist with the Centers for Disease Control and Prevention in Atlanta, said there were 21,000 cases of whooping cough nationwide in 2010. The actual number may be 20 percent higher once reports are finalized.
CDC officials expect a similar number of cases this year, including up to 20 deaths.
Clark said 90 percent of the deaths involve infants. That's an important reminder for parents of newborns to get their booster shots to prevent transmission, he said. The CDC recommends a series of five shots before children starting school.
Utah Department of Health officials initially feared hundreds were exposed to measles during the recent outbreak near Salt Lake City. But only nine cases have been confirmed, and the quarantine may be lifted May 18.
Nationwide, there have been 98 confirmed measles cases so far in 2011. That's nearly double the number typically seen in a year, and health officials say the country appears on track to have more measles cases than any year in more than a decade.
Europe, especially France, has been hit hard by measles this year, with more than 6,500 cases reported in 33 nations. International health officials are blaming it on the failure to vaccinate all children.