With nine deaths and 4,017 illnesses reported, California is on track to break a 55-year record in pertussis, or whooping cough, infections — a highly contagious upper respiratory illness that affects children in disproportionate numbers.
California now has one-third of the country’s whooping cough cases. One reason public health experts believe the state has such high infection rates is cultural: a squeamishness about vaccinations among parents. One pediatrician called California the “epicenter of vaccine refusal,” because the state’s schools allow parents to opt out of immunizations for reasons of religion or personal belief.
Partly to blame is the obdurate belief among many parents that the mercury-based preservative, thimerosal, in vaccines is linked with autism spectrum disorders. (The vaccination for whooping cough does not contain thimerosal.)
Research has consistently shown that vaccine preservatives do not cause autism. A watershed study showing a link was retracted by The Lancet earlier this year, amidst controversy over its methodology. More recently, a Sept. 13 article in Pediatrics reported research conducted by the director of the immunization safety office at the U.S. Centers for Disease Control and Prevention finding no link between vaccines and the developmental disorder.
“Prenatal and early life exposure to ethylmercury from thimerosal in vaccines or immunoglobulin products does not increase a child’s risk of developing autism,” wrote author Dr. Frank DeStefano.
California’s public health office is working to contain the outbreak. Beyond California, neighboring Oregon is reporting heightened rates of the infection. Ohio, also, is on alert after reports from hospitals of some whooping cough patients.
Because symptoms of the illness resemble a cold, pediatricians are advising parents to be especially vigilant with their children. Further, all of the deaths occurred in babies too young to have been immunized, so parents and caretakers are being advised to get booster shots to avoid spreading the disease to such a vulnerable population.