The number of whooping cough, or pertussis cases reported in the California epidemic in 2014 has eclipsed 10,000, and the counting is still ongoing.

California pertussis 1/7/15
California pertussis 1/7/15

The California Department of Public Health (CDPH) reports the preliminary numbers to be 10,831 cases with onset in 2014.

Los Angeles and San Diego have seen the most cases with nearly 2,000 cases a piece reported.

In June, health authorities declared pertussis and epidemic in the state.  The last epidemic in California occurred in 2010 when the state experienced 9,159 cases, the most in 6 decades; however, the overall incidence of pertussis has increased since the 1990s. In fact, pertussis incidence is higher than was reported in 2010 with a state rate of 28.35 cases per 100,000 population.

Approximately 3.5 percent of all cases required hospitalization, with a quarter of them requiring intensive care treatment. Two pediatric deaths were reported in 2014.

One reason for the increase is the use of acellular pertussis vaccines, which cause fewer reactions than the whole-cell vaccines that preceded them, but do not protect as long. Young infants are at greatest risk of hospitalization and death from pertussis, therefore pregnant women are encouraged to receive pertussis vaccine (Tdap) during the 3rd trimester of every pregnancy. Pertussis antibodies are transferred from vaccinated mothers to their infants and will help protect them until they are old enough to be vaccinated.

The primary DTaP vaccine series is essential for reducing severe disease in young infants and should not be delayed. DTaP can be given to infants at an accelerated schedule with the first dose given as early as 6 weeks of age. Even one dose of DTaP may offer some protection against severe pertussis disease in infants.

Whooping cough is a highly contagious bacterial disease that can be spread by coughing. People with pertussis have severe coughing attacks that can last for months. Infants too young for vaccination are at greatest risk for life-threatening cases of pertussis.