The impact of re-vaccination implementation on morbidity of mumps in the Kyrgyz Republic

Abstract

The article presents results of evaluation of long-term dynamics of morbidity of mumps in the Kyrgyz Republic (KR) in the pre-vaccination period, after the introduction of routine mass immunization in 1978 and in beginning of re-vaccination since 2015. The pronounced trend of increasing of morbidity was noted since 1970. In 1978, the morbidity increased up to 194 times as compared to 1948. The annual growth rate was made up to 7.7%. The application of vaccination significantly effected morbidity and prevalence of mumps in the Republic. In the long-term dynamics a pronounced trend of morbidity decreasing with annual decreasing rate of 7.5%. In 2015, re-vaccination of children of 6 years old was introduced in the Republic. This action resulted in morbidity decreasing during the next three years (2016, 2017 and 2018). However, in 2019, an outbreak of morbidity covering both children under 14 years and the adults was registered. The level of IgG to virus of mumps was determined by enzyme-linked immunosorbent assay using the test-system "VectoParotit-IgG" (by Vector BEST, Russia). The analysis of seroepidemiological study established the highest specific weight of seronegative individuals in the age group of 1-4 years (51.5%, 95% CI 42.9-60.1), and proportion of seropositive individuals falls on the age groups of 30 years and over (85, 4%), 10-14 years (62%), 5-9 years (61.5%), 15-19 years (60%).