Delaware Division of Public Health (DPH) is providing the following mumps update to the medical community and continues to encourage providers to immediately report any suspect mumps cases to DPH. CDC and state and local health departments continue to investigate a multi-state outbreak of mumps that began on a college campus in eastern Iowa in December 2005.
DPH has investigated several suspect cases of mumps. To date, no cases of mumps have been confirmed in Delaware this year.
As of May 18, 2006, 11 states (Iowa, Nebraska, Illinois, Kansas, Mississippi, Pennsylvania, South Dakota, Wisconsin, Colorado, Minnesota and Massachusetts) reported nearly 4000 cases of mumps. Of those, over 50% are from Iowa. This figure represents confirmed, probable and suspect cases. This is the largest number of mumps cases reported to CDC in a single year since 1991.
During this outbreak, the incidence rate has been highest among persons aged 18-24 years, many of whom are college students. The peak week of onset has been April 2-8, 2006 in Iowa and April 16-22, 2006 in other states. Multiple factors may have contributed to the spread of mumps in this outbreak and on college campuses such as frequent and extended close contact with other students, low vaccination rates due to some college admission requirements not requiring 2 doses of MMR, less than 100% effectiveness of MMR vaccine, waning immunity and delayed recognition and diagnosis of mumps cases.
The Advisory Committee on Immunization Practices (ACIP) recommends a 2-dose MMR vaccination series for all children, with the first dose administered at ages 12-15 months and the second dose at ages 4-6 year. Two doses of MMR are recommended for school and college entry unless the student has other evidence of immunity.
On May 17, 2006, ACIP redefined evidence of immunity to mumps through vaccination as follows: 1 dose of a live mumps virus vaccine for preschool children and adults not at high risk; 2 doses for children in grades K-12 and adults at high risk (i.e., healthcare workers, international travelers and college students). Other criteria for evidence of immunity (i.e., birth before 1957, documentation of a confirmed mumps case, or laboratory evidence of immunity) are unchanged.
Healthcare facilities should consider recommending 1 dose of MMR vaccine to unvaccinated healthcare workers born before 1957 who do not have other evidence of mumps immunity.
Mumps is required to be reported to DPH by rapid means. Suspect cases should be immediately reported to Epidemiology at 1-888-295-5156 or 302-744-4541. The 888 number is available during normal business hours and for emergencies during non-business hours.
Additional information regarding mumps can be found at: http://www.cdc.gov/nip/diseases/mumps/default.htm