The measles outbreak in Davis County may have peaked at 107 cases, with no new cases reported so far this week.
Health department nursing director Mary Meredith said Tuesday the number of new cases reported has tapered off over the past two weeks.But health officials are not declaring the outbreak over, she said. New cases could still be reported, and some cases could occur and not be reported with students out of school for the summer.
Meredith called the outbreak, now in its 13th week, "expensive, time-consuming and very stressful." The department has spent $4,500 just on extra needles for additional immunizations.
The outbreak has also stretched her staff to its breaking point, Meredith told the county health board, with one nurse working full-time and a second part-time on isolated infected individuals and tracing their contacts to contain the outbreak.
The nursing division expanded its normal immunization clinic schedule and set up special clinics in affected schools. As an example, Meredith said her division usually provides about 1,000 clinic services a month in May. This year the figure leaped to 6,000.
Meredith said the first case was identified March 11, but the second case was not reported, with the department finding the third case on April 5.
"By the third case, we realized we had a problem. The second case that was not reported to us exposed many, many others," Meredith said. Even now, with all the publicity the outbreak has received, some cases are still not being reported, she said.
The outbreak apparently peaked in its 10th week, with 28 reported cases. In its 11th and 12th weeks, the numbers of new cases have tapered off, Meredith said. "I think we're on the downside of it," she told the board.
Because new cases were reported in the 11th week and the disease has a 14-day incubation period, Meredith said she expects some new cases could still be reported in this, the 13th week.
"We could have some new cases, but with the immunization program we put on and the fact that school is out for the summer, we don't expect another outbreak like the last one," Meredith said.
There are eight year-round schools in the county and youngsters still get together, congregating at malls and other places, Meredith said.
Meredith also reported the outbreak shows a disturbing trend. Of the 107 cases reported so far, 43 - just under half - were people defined as being adequately immunized.
It could be that immunity wanes over time, especially if the immunization is given at around 15 months, Meredith said. It could be a case of vaccine failure, or they could be part of the 5 percent of the population that is not affected by immunizations, she said.
Eighteen cases were reported by individuals who chose for personal reasons not to be immunized or have their families immunized, Meredith said, which state law allows. But from those 18 cases, Meredith said 40 infections can be traced.