OLYMPIA, Wash. (AP) -- State health officials say whooping cough is a growing problem in Washington state.
The number of cases has increased by more than 50 percent between 2010 and 2011.
The state reports 912 cases of whooping cough in 2011. That's the highest number in six years. Six hundred and eight cases were reported in 2010.
Health officials say the actual number could be higher because many people who are ill with the highly contagious respiratory illness also known as pertussis may not know they have it and won't seek medical attention.
Whooping cough is spread by coughing and sneezing and it affects people of all ages. It is most serious in infants.
Health officials now recommend women get vaccinated for pertussis later in pregnancy, which would pass protection on to their babies.