Before the vaccine’s introduction, mumps was a common childhood disease, with the highest number of cases in children ages 5-9 years.[2]Hviid A, Rubin S, Muhlemann K. Mumps. Lancet. 2008 Mar 15;371(9616):932-44.
http://www.ncbi.nlm.nih.gov/pubmed/18342688?tool=bestpractice.com
A review of worldwide serosurveys to assess mumps immunity showed that 50% of children ages 4-6 years and 90% of children ages 14-15 years were seropositive, indicating that nearly all people in an unvaccinated population would become infected. In countries without vaccination against mumps virus, the incidence remains high, with epidemic peaks every 2-5 years.[3]Galazka AM, Robertson SE, Kraigher A. Mumps and mumps vaccine: a global review. Bull World Health Organ. 1999;77(1):3-14.
http://www.ncbi.nlm.nih.gov/pubmed/10063655?tool=bestpractice.com
After the introduction of the mumps vaccine in 1967, the incidence of the disease declined initially by 99% in the US. Subsequently, outbreaks of mumps were reported between 1986 and 1987 in people born too early to receive the mandatory vaccine for school entry, leading to revised vaccine guidelines for young children and college-aged adolescents.[7]Watson JC, Hadler SC, Dykewicz CA, et al. Measles, mumps, and rubella - vaccine use and strategies for elimination of measles, rubella, and congenital rubella syndrome and control of mumps: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 1998 May 22;47(RR-8):1-57.
http://www.cdc.gov/mmwr/preview/mmwrhtml/00053391.htm
http://www.ncbi.nlm.nih.gov/pubmed/9639369?tool=bestpractice.com
This was followed by historically low rates of mumps and a goal for its elimination by 2010.[8]Dayan GH, Quinlisk MP, Parker AA, et al. Recent resurgence of mumps in the United States. N Engl J Med. 2008 Apr 10;358(15):1580-9.
https://www.nejm.org/doi/full/10.1056/NEJMoa0706589#t=article%E2%80%8B
http://www.ncbi.nlm.nih.gov/pubmed/18403766?tool=bestpractice.com
However, in 2006, the US reported 6584 people with mumps (an increase from 314 cases in 2005).[9]Centers for Disease Control and Prevention. Mumps cases and outbreaks: reported US mumps cases by jurisdiction and year. Jan 2024 [internet publication].
https://www.cdc.gov/mumps/outbreaks.html
Most of these cases were seen in the Midwest and occurred in people ages 18-24 years who were attending college. Additionally, most cases occurred in vaccinated individuals.[10]Marin M, Quinlisk P, Shimabukuro T, et al. Mumps vaccination coverage and vaccine effectiveness in a large outbreak among college students - Iowa, 2006. Vaccine. 2008 July 4;26(29-30):3601-7.
http://www.ncbi.nlm.nih.gov/pubmed/18539365?tool=bestpractice.com
Since 2006, reported numbers have fluctuated, decreasing to 229 in 2012, and peaking again at over 6000 in 2016 and 2017.[9]Centers for Disease Control and Prevention. Mumps cases and outbreaks: reported US mumps cases by jurisdiction and year. Jan 2024 [internet publication].
https://www.cdc.gov/mumps/outbreaks.html
In 2020, the number of reported cases decreased sharply compared with 2019 (reducing from 3780 to 616), possibly due to COVID-19 restrictions, with cases remaining low in 2021, 2022, and 2023 (154, 322, and 436, respectively).[9]Centers for Disease Control and Prevention. Mumps cases and outbreaks: reported US mumps cases by jurisdiction and year. Jan 2024 [internet publication].
https://www.cdc.gov/mumps/outbreaks.html
There is no difference in the prevalence of mumps between men and women. However, men are more likely to have complications, particularly neurologic complications.[2]Hviid A, Rubin S, Muhlemann K. Mumps. Lancet. 2008 Mar 15;371(9616):932-44.
http://www.ncbi.nlm.nih.gov/pubmed/18342688?tool=bestpractice.com