The California Department of Public Health (CDPH) released their latest update Friday on the measles outbreak that began in Disneyland around December 17th. For the first time since the CDPH began posting updates on-line on February 9th, no new measles cases were added to their statewide counts.
“Since December, 2014, there have been 133 confirmed measles cases reported in California residents” read the opening line of the March 20th version of the California Measles Surveillance Update. “No new confirmed cases have been reported to CDPH since the publication of the last report on March 13, 2015.”
So can we officially declare the so-called Disneyland measles outbreak over? Not so fast, says the CDPH.
“The outbreak will be considered over when 42 days have elapsed from the end of the infectious period of the last known B3 measles cases that was a not a new importation. As of today, that date will be April 17, 2015.”
So let’s do that math. If the CDPH will be ready to officially declare the outbreak finished a full 42 days after the infectious period of the last reported case ends, then that milestone has been passed already, fully two weeks ago on March 6th.
But the end of the infectious period is perhaps less important to specifying the final ebb of the measles outbreak than the date the last reported case became infected. The CDPH also states (see HERE) that “Infected people are usually contagious from about 4 days before their rash starts to 4 days afterwards”, so this last reported case probably saw their rash appear on March 2nd and were first infectious themselves around February 26th. As for the date of their first exposure, one analysis of the outbreak (see HERE) suggests that exposures to the measles virus occur roughly 10 days before the rash appears. That would put the date of infection of the last case around February 20th.
In other words, the last California resident who got sick from measles caught it a month ago.
The CDPH won’t make the declaration official for nearly another month, and there’s always a chance another case or two might pop up elsewhere, but it’s reasonable to assume (and the CDPH has formally acknowledged the possibility) that an important milestone has been reached.
The Disneyland measles outbreak is over.
Note: Age of Autism spoke to a CDPH spokesperson who was not willing to confirm the specific dates listed above. He requested that we put our questions in writing and as of the posting time, we had not yet received a response.
Mark Blaxill is Editor-at-Large for Age of Autism and author of The Age of Autism Mercury, Medicine and a Manmade Epidemic, Vaccines 2.0 and The Invisible Edge.