Measles: lessons from an outbreak.

BACKGROUND

Measles outbreaks continue to be a problem for infection control in hospitals--patients, personnel, and employee health service. Guidelines for measles outbreaks are not clear for medical personnel in the hospital.

METHODS

Outbreak investigation in a university-affiliated teaching hospital.

RESULTS

Four primary cases resulted in 607 staff exposures and two secondary cases. Forty-seven medical personnel were furloughed and 88 were vaccinated for measles. Minimal serologic criteria for immunity were found to be inadequate in the outbreak setting.

CONCLUSIONS

We found that serologic guidelines for assessing immunity to measles are inadequate. During the outbreak, we arbitrarily doubled the acceptable enzyme-linked immunosorbent assay titers that we would consider protective, > or = 2, to decrease the possibility of further secondary cases. Employees with enzyme-linked immunosorbent assay measles titers less than 2 and without a definite history of natural measles were revaccinated with a measles vaccine. This strategy takes advantage of the anamnestic response that revaccination would confer in persons with low antibody titer.