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

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%).

[The epidemic process of whooping cough at contemporary stage in the Republic of Kyrgyzstan]

The causes of epidemic outbreaks of pertussis infection in the Kyrgyz Republic were studied in order to optimize immunological surveillance of this infection. The object of the study was the epidemic process of whooping cough, and the subject of the study was the incidence of pertussis infection in 2009-2018 and official data on the outbreak of pertussis in 2018. To diagnose pertussis the bacteriological method was applied. The bacteriological inoculation of the samples was carried out in the laboratory of the Republican Clinical Infectious Diseases Hospital. The smear from posterior pharyngeal wall was collected from 2153 patients. The level of pertussis antibodies was determined by enzyme-linked immunosorbent assay (ELISA) using the RIDASCREEN Pertussis IgG test system (R-Biopharm, Germany) in various series. The study data testifies that despite the vaccine prevention and high inoculation coverage, the epidemic increases occurred in incidence of whooping cough in 2015 and 2018 with an intensive rate of 4.7 and 9.6 per hundred thousand of population, respectively. The evaluation of vaccination status of patients demonstrated that out of them 80.7% were non-immunized; the percentage of vaccinated patients made up to 13.1%. The analysis of the age structure testifies that the main group of the diseased consisted of children under one year of life (63.1%), the second group consisted of children aged 1-4 years (33.1%). The severe forms of infection were observed among children under one year of age (95.8%). According to the territorial distribution, the largest percentage of cases fall on Bishkek - 70% (426 cases) and Chuyskaya Oblast - 22.4% (137 cases). The sero-epidemiological study revealed high proportion of seronegative individuals in all studied groups, and the highest percentage was observed in the group of children 5-9 years old and adolescents of 15-19 years old - 62.8% and 62%, respectively.

[The condition of post-vaccination immunity to diphtheria and tetanus in population of the Republic of Kyrgyzstan]

The serologic epidemiological analysis of intensity of anti-diphtheria and anti-tetanus post-vaccination population immunity in the Republic of Kyrgyzstan was carried out. The presence of immune defense was determined in 453 residents by detecting IgG to diphtheria and tetanus by enzyme-linked immunosorbent assay using test system RIDASCREEN Diphtherie IgG and RIDASCREEN Tetanus IgG (Germany, R-Biopharm). It was established that the level of antibodies depends on the age of individuals. The highest immune defense against diphtheria is present in adult population aged 20-29 years (100%) and 30 years and older (100%). The lowest level is detected in the group of children of 1-4 years old and is up to 30.6%. The proportion of individuals with protective titer of antibodies ≥ 0.10 for diphtheria was 88.5%. The population intensity of post-vaccination tetanus immunity high antibody titers were established in age groups of 15-19 years (92.9%), 20-29 years (93.3%) and 30 years and older (94.8%). There is relationship between level of antibody titers and the age. Thus, in children age group of 5-9 years, high level of protection was established, that amounted up to 60.4%, in adolescents of 10-14 years old this indicator was 40%, and the lowest level in children aged of 1-4 years old was 39.6%.