SALT LAKE CITY — The Salt Lake Valley Health Department on Tuesday announced an official end to a short-lived measles outbreak that lasted throughout most of the month of April and resulted in more than 12,000 individuals contacted and 184 ending up on voluntary quarantine.

No new cases have been confirmed in the past 28 days, signaling a stop to the pervasive illness that infected at least nine individuals since the first case was confirmed on April 7. The health department estimates that 3,000 hours were spent tracking measles, resulting in a not-yet-final cost of $130,246.

Nearly $13,000 was spent in issuing measles vaccines to 196 children and adults who were not immunized. Lab testing and staff time spent contacting individuals made up the remaining costs.

"The impact of these nine cases should not be underestimated," said Dr. Dagmar Vitek, medical officer for the SLVHD. "This outbreak brought a lot of awareness to the issues surrounding school immunization exemptions and their impact on a total community."

While Salt Lake County maintains an average 97 percent immunization rate, approximately 17,300 school-age children are unprotected from the disease, as well as thousands of infants and individuals with compromised immune systems who cannot receive the vaccine. Utah schools allow for an exemption from immunization requirements based on religious or personal decisions, but paperwork has to be filed with the appropriate districts.

SLVHD executive director Gary Edwards credits the high vaccination rates as well as the quick response of Granite School District officials in helping to prevent the highly contagious disease from spreading further.

Seven of the county's nine confirmed cases appeared in students this year, with the cases believed to have originated from a local family's trip to Poland to pick up a missionary.

"Even though this outbreak is over, measles and other vaccine-preventable diseases continue to circulate," Vitek said, adding that it is important for individuals to keep their vaccinations up to date.

While five students acquired the disease because they had not been vaccinated, two of the seven students had received at least one measles vaccination shot. Having both doses of the vaccine is 98 percent effective, leaving a small 2 percent of those vaccinated vulnerable, according to SLVHD spokeswoman Pam Davenport.

"Vaccination is the best way to protect an individual and our community, but it happens," she said.

Davenport said costs will continue to mount because additional follow-up work is necessary, adding to the hours spent on this particular outbreak.

Actual costs to the community, however, are difficult to calculate because of all the work and school functions that were missed by those asked to remain isolated while the disease ran its course, Davenport said. The outbreak affected not only the state and local health departments, but area hospitals, clinics and private providers, day care centers, four schools within the Granite School District, as well as the district itself, a community college and two large community gatherings.

"Because there continues to be measles outbreaks in other parts of the world and across the country, it is nearly impossible to definitively say that we will not see any more measles cases this year," Edwards said.