An outbreak of measles among visitors to Disneyland has grown to at least 20 cases across four states, as of Sunday. The majority of the cases remain centered in California, while others who were infected have sought treatment after returning home to Utah, Colorado, and Washington state. The California Department of Health has said that visitors were likely exposed at the park between Dec. 15 and Dec. 20.
The outbreak comes amid rising concerns over the vaccination levels of children in California. The Los Angeles Times reports that since 2002, vaccinations among kindergartners in the state have declined from 95 percent to 92 percent, a drop that leaves the population vulnerable to diseases such as measles and whooping cough. From the Times:
Orange County authorities Friday reported two more cases of measles and repeated warnings that the outbreak that began at Disneyland is expected to continue to spread.
The disease, rare in the United States but highly contagious and potentially serious, has now infected at least eight people in Orange County and more than a dozen statewide.
It causes fever, rash, coughing and red, watery eyes. Those infected are contagious from about four days before the rash appears through four days after.
Measles can be transmitted through the air by coughing or sneezing, and an infected person can unknowingly spread the disease until symptoms appear several days later. Those most in danger of contracting the illness include very young children, patients taking immunosuppressant drugs, and others who cannot safely be vaccinated. The "herd immunity" of a largely vaccinated population that has protected those groups is steadily eroding as vaccination rates drop. According to ThinkProgress, two of the cases in the most recent outbreak involve infants who are not old enough to receive the vaccine.
A study published in 1998 purporting to show a link between vaccines and autism has been shown to have been built on fabricated data, but Dr. Andrew Wakefield's fraudulent research continues to influence the debate, thanks in part to celebrities and other high-profile endorsers who have spread his conclusions. The perceived threat of autism stirred by Wakefield's bad medicine has the possibility of leading to a resurgence in communicable diseases with the capacity to deafen, scar, or even kill the most vulnerable among us.