Estimated burden of mumps patients based on clinical and laboratory-based data from sentinel surveillance, 2015 – 2017, Japan
- Vaccine preventable diseases
Background
In Japan, mumps vaccine is not routinely recommended, with a coverage rate for mumps vaccine being approximately 30%, resulting in an epidemic every 4-5 years. Mumps is monitored through sentinel surveillance, requiring approximately 3,000 sentinel sites to report clinically diagnosed mumps cases weekly in aggregate form by age and sex. 10% of these sentinel sites are designated as sentinel sites for laboratory-based surveillance, with sample collection for mumps laboratory testing. Thus, data on the disease burden of laboratory-confirmed mumps and mumps-associated complications in Japan is limited. The purpose of this study was to estimate the disease burden of mumps in Japan by utilizing data from laboratory-based surveillance sentinel site (LBSSS).
Methods
We choose Kanazawa City (KC), a population of 465,700, as its age distribution is similar to that of Japan’s population. KC has 10 sentinel sites, including one LBSSS. A laboratory-confirmed case was defined as a person testing positive by laboratory test (i.e. immunoglobulin M antibodies, immunoglobulin G antibodies and/or RTPCR). We estimated the number of laboratory-confirmed mumps cases in KC and Japan, using proportions of cases testing positive in clinically-diagnosed cases by age and year at the LBSSS. In addition, we used previous study results to estimate the number of complications due to laboratory-confirmed mumps (deafness and aseptic meningitis, 0.1% and 1.2% of all mump cases, respectively).
Results
The numbers of laboratory-confirmed mumps cases in 2015-2017 were estimated to be 4,147 [95%CI: 3,759-4,536] in KC and 994,528 [95%CI: 886,140-1,102,916] in Japan. Deafness and aseptic meningitis were respectively estimated as 995 [95%CI: 886-1,103] and 11,934 [95%CI: 10,634-13,235].
Conclusion
Utilizing proportion by age and year from LBSSS, we estimated the number of laboratory-confirmed mumps cases and its complications in KC and in Japan. The results suggest the necessity of introducing mumps vaccine as a routine vaccination.
In Japan, mumps vaccine is not routinely recommended, with a coverage rate for mumps vaccine being approximately 30%, resulting in an epidemic every 4-5 years. Mumps is monitored through sentinel surveillance, requiring approximately 3,000 sentinel sites to report clinically diagnosed mumps cases weekly in aggregate form by age and sex. 10% of these sentinel sites are designated as sentinel sites for laboratory-based surveillance, with sample collection for mumps laboratory testing. Thus, data on the disease burden of laboratory-confirmed mumps and mumps-associated complications in Japan is limited. The purpose of this study was to estimate the disease burden of mumps in Japan by utilizing data from laboratory-based surveillance sentinel site (LBSSS).
Methods
We choose Kanazawa City (KC), a population of 465,700, as its age distribution is similar to that of Japan’s population. KC has 10 sentinel sites, including one LBSSS. A laboratory-confirmed case was defined as a person testing positive by laboratory test (i.e. immunoglobulin M antibodies, immunoglobulin G antibodies and/or RTPCR). We estimated the number of laboratory-confirmed mumps cases in KC and Japan, using proportions of cases testing positive in clinically-diagnosed cases by age and year at the LBSSS. In addition, we used previous study results to estimate the number of complications due to laboratory-confirmed mumps (deafness and aseptic meningitis, 0.1% and 1.2% of all mump cases, respectively).
Results
The numbers of laboratory-confirmed mumps cases in 2015-2017 were estimated to be 4,147 [95%CI: 3,759-4,536] in KC and 994,528 [95%CI: 886,140-1,102,916] in Japan. Deafness and aseptic meningitis were respectively estimated as 995 [95%CI: 886-1,103] and 11,934 [95%CI: 10,634-13,235].
Conclusion
Utilizing proportion by age and year from LBSSS, we estimated the number of laboratory-confirmed mumps cases and its complications in KC and in Japan. The results suggest the necessity of introducing mumps vaccine as a routine vaccination.