California’s whooping cough cases have reached epidemic level, causing concern for citizens.

According to California’s public health agency, there have been 800 new cases documented in the last two weeks. As of June 10, there have been 3,458 cases of the infection, formerly known as pertussis; that is more than the entire number of cases for the whole year of 2013.

The people who are at the highest risk of contracting whooping cough are infants, and already two have died since the outbreak began. “Our biggest concern is always infants,” Stacey Martin, an epidemiologist with the U.S. Centers for Disease Control and Prevention’s division of bacterial diseases, said. “There’s a gap in coverage between birth and the first vaccine.”

Whooping cough is caused by the bacterium Bordetella pertussis. The symptoms of the infection vary by age. In children, whooping cough can start out with cold like symptoms, and progress to a violent cough, making it hard to breathe. Many times, infants will not have the cough, but will instead suffer from something called apnea which is a pause in the child’s breathing patters. According to the CDC, approximately half of infants under the age of one, who contract the infection, will have to be hospitalized. A person is typically most contagious up to two weeks after the coughing fits begin.

Below is a disease progression chart that shows how the infection will progress after diagnosis.

California’s health department director Ron Chapman explained that by vaccinating pregnant women and infants, the state is significantly cutting down on the likelihood of these people contracting the infection. The CDC recommends for infants to receive their immunization as early as six weeks after birth because the vaccine given to the pregnant mother can soon wear off, leaving the infant vulnerable.

Image via Wikimedia Commons, CDC.com