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

Abstract

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.