Idaho health officials on Tuesday urged vaccination to combat what they said was an alarming rise this year in the number of cases of whooping cough, which has killed an infant and afflicted 240 other state residents since January.
The 241 cases of whooping cough, or pertussis, reported in Idaho from January to July compares to the 122 and 129 cases reported during the same period in 2013 and 2012 respectively.
The Idaho Department of Health described the latest outbreak as "troubling," but said it could be eased by vaccination.
"The best way to protect children and infants from pertussis is to get vaccinated so you are protected and then you drastically reduce the risk of passing it on to extremely vulnerable infants," Mitch Scoggins, program manager for the Idaho Immunization Program, said in a statement.
Rates of whooping cough are highest among children aged 5 to 17 in Idaho, which has one of the lowest vaccination rates in the United States, Scoggins said.
Idaho last marked the death of an infant from pertussis, which causes severe coughing attacks and can bring convulsions and pneumonia, in 2012. The per-capita occurrence in the state has risen higher than the national average since 1987, health officials said.
A pertussis epidemic broke out this year in California, its second since 2010, according to that state's Department of Public Health. More than 6,930 cases of whooping cough have been confirmed there so far this year in an outbreak that has claimed the lives of three infants and hospitalized 199 people.
Worldwide, the ailment affects 30 to 50 million a year and kills roughly 300,000, mostly children in the developing world, according to the federal Centers for Disease Control and Prevention.