BAKERSFIELD, Calif. -- The number of cases of whooping cough, or pertussis, has quadrupled this year compared to all of last year, causing state health officials to declare an epidemic.

"Yesterday, the California Department of Public Health stated we are on pace to suffer the most illness and deaths in California in the last 50 years. Pertussis is now an epidemic in California," said Matt Constantine, director of Public Health, during a news conference Thursday.

Whooping cough is a highly contagious bacterial infection that attacks the respiratory system. Anyone can catch it, but it's infants and young children who are most susceptible. "The coughs are so violent. It's been associated with cracking ribs," said pediatric Dr. Edmond Sarraf.

So far, California has recorded 910 cases of Pertussis compared to 219 cases last year. Five infants have died, according to reports.

"Their immune system is a little weaker, their air tubes smaller so they struggle a lot more to breathe," said Saraff.

Here in Kern County there are 75 cases, 45 of which were reported in June alone. People throughout the county have been infected but the highest concentration is in central and east Bakersfield, with Hispanics accounting for more than half of the cases. The reason for that is unknown.

"Many of the carriers are teens, 20, 30 year olds or parents. We may carry it in our passages but not get sick by it," said Saraff.

Saraff said those that do get sick are often misdiagnosed as having bronchitis or pneumonia because whooping cough is often thought of as a child's illness. They then unknowingly pass on the infection. Which is why health officials are urging everyone to get vaccinated. You can find the vaccine for pertussis at your doctors office, any H1N1 vaccine clinic or the Public Health Department.