Objective. To describe the epidemic process of pertussis in Belarus over an 8-year period (2012—2019) based on the results of an extended laboratory diagnosis.
Materials and methods. In total 4113 pertussis cases registered from 2012 to 2019 were analyzed. Nasopharyngeal swabs were tested by culture and real-time PCR assays targeting IS481, IS1001, h- IS1001, flaA genes. IgG antibodies to pertussis toxin were detected in sera samples by ELISA.
Results. The incidence rate of pertussis in the country ranged between 2.0 and 6.9 per 100 000 with a slight increase to 8.2/100 000 in 2019. The rise in notification was observed in the summer months and was weaker in January and December. Children 0—14 years old dominate accounting for 90% among all patients with the highest notification rates among infants of the first year of life (the average long-term incidence rate for 8 years of observation was 101.8 cases per 100 000 versus 22.5; 29.9 and 19.4 respectively among children 1—4 years old, 5—9 years old and 10—14 years old). The proportion of unvaccinated or not fully vaccinated (1—2 doses) among sick children 3—11 months old was 88.9%, among children 1—4 years old — 62.5%. Persons not vaccinated for reasons not related to age accounted for 32,3% of the total number of cases. The proportion of fully vaccinated among patients 5—19 years of age was 74.3%, which indicates immunity depletion with age. The main sources of pertussis for children under one year of age were siblings of 6—13 years old (54.6%) and parents (32.0%) with a mother being 4 times more likely than father.
Conclusion. To reduce the incidence and for further control of the infection it is necessary to ensure timely and maximum possible vaccination coverage for children in accordance with the existing vaccination schedule, as well as to consider expanding the existing immunization schedule.Ключевые слова:
Автор(ы): V. L. Kolodkina, S. V. Martinov