Whooping cough is now at epidemic levels in California and the state could record the highest number of illnesses and death due to the disease in 50 years, the state's top health official said Wednesday.
Reported cases of whooping cough, also known as pertussis, have quadrupled since the same time period last year, said Dr. Mark Horton, director of the California Department of Public Health. Five infants -- all under 3 months of age -- have died, including two in Los Angeles County and one in San Bernardino County.
Whooping cough is a bacterial disease that infects the respiratory system. There have been 910 confirmed cases of the highly contagious disease in California this year between Jan. 1 and June 15. During the same time last year, 219 cases were confirmed.
An additional 600 possible cases are being investigated.
Los Angeles County has reported 148 suspected pertussis cases, said county health officer Jonathan Fielding. He urged family members of infants and anyone else who cares for them to get a booster shot.
An infant's siblings and parents are among the most likely people to infect a newborn. Fielding urged anyone who has a cough avoid infants.
Young infants can become gravely ill rapidly with pertussis, and health officials recommend that those with even very early symptoms be treated with antibiotics. They also say that doctors should strongly consider hospitalizing ill infants in a facility with access to an intensive care unit.
Although many people may think they are still protected from whooping cough because they received inoculations as a child, immunity can begin fading five years after the immunization.
In May, state health officials warned that physicians often don't make prompt diagnosis of the whooping cough in infants because newborns often have initially deceivingly mild symptoms -- such as a runny nose with an undetectable or mild cough.