In February 2015, a total of 367 doses of MMR or measles, mumps, rubella, and varicella (MMRV) vaccine were administered at NRPH general immunization clinics.
Staff from these public health units instituted disease control measures to manage susceptible contacts and exposure settings and to rule out epidemiologic links to cases from TPH or NRPH.
Although some overlapping exposures were identified, no epidemiologic links could be confirmed among the index case in NRPH or any of the cases in Toronto, York Region, or Halton Region.
As further cases were reported, NRPH declared an outbreak and engaged in active surveillance and risk communication with local physicians and public health departments in Ontario and the U.S., provincial public health officials, and Canadian public health practitioners to encourage enhanced surveillance for cryptosporidiosis, appropriate testing, and reporting to local public health.
On December 9, 2010, a laboratory-confirmed case of cryptosporidiosis was reported to NRPH (case 4).
Concurrently, NRPH was receiving alerts through the emergency department syndromic surveillance system for gastrointestinal illness.