Epidemiological features of whooping cough in children in Sumy city

Проаналізовано результати епідеміологічного обстеження 238 випадків кашлюку серед дітей у місті Суми з 2001 по 2016 рр., враховуючи вік, сезонний розподіл, вакцинний статус. Встановлено, що за останні 15 років відмічається певна циклічність захворюваності на кашлюк з періодами зменшення частоти випадків хвороби до значного їх збільшення. У той же час, незважаючи на циклічність перебігу, останніми роками намічається тенденція до збільшення захворюваності на кашлюк серед дитячого населення, причому показник захворюваності серед когорти щеплених дітей залишається на досить високому рівні і складає 51,4 %. Більш вразливішими є діти до 1 року та школярі. Найбільша захворюваність на кашлюк у дітей спостерігалась у осінньо-зимово-весняний період.Проанализированы результаты эпидемиологического обследования 238 случаев коклюша среди детей города Сумы с 2001 по 2016 гг., учитывался возраст, сезонное распределение, вакцинный статус. Установлено, что за последние 15 лет отмечается определенная цикличность заболеваемости коклюшем с периодами уменьшения частоты случаев болезни и периодами значительного их увеличения. В то же время, несмотря на цикличность течения, отмечается тенденция к увеличению заболеваемости коклюшем среди детского населения, при этом показатель заболеваемости среди когорты вакцинированных детей остается стабильно высоким и составляет 51,4 %. Более уязвимыми являются дети до 1 года и школьники. Наибольшая заболеваемость коклюшем у детей наблюдалась в осенне-зимневесенний период.Introduction. Pertussis is an acute infectious disease of bacterial etiology, with an airborne mechanism of transmission, the causative agent of which is V. pertussis and with a high index of contagiousness. In recent years, the incidence rate of the pediatric population for pertussis remains rather high and tends to increase, which may be due not only to low postvaccinal immunity, but also an increase in the age of children under 18 years of age. Despite the fact that in most developed country in the world, the percentage of children covered by vaccination against pertussis is quite high and reaches 90–95%, whilst infectious diseases, according to WHO, affect about 60 million people in the world and about 1 million children die, mainly at the age of 1 year. In Ukraine, 90–95% of children are vaccinated against pertussis every year, while in the country, 3–4,000 cases of the disease are registered among children, mostly up to 1 year old, and from 2 to 10 deaths annually. There is a tendency for an increase in the structure of the diseased portion of vaccinated children. Therefore, for the timely diagnosis of a whooping cough, a very important combination of understanding of the epidemiological and clinical features of the disease at the present stage, especially among the children's population. Purpose. Study of epidemiological features of a pertussis in children at the present stage in Sumy. Materials and Methods. 238 cases of pertussis disease that were registered during the reporting period in Sumy were analyzed. The data were subjected to an epidemiological analysis, which included: studying the long-term dynamics of the disease from 2000 to 2016; seasonal dynamics of morbidity; distribution by age, vaccine status. Discussion. It has been established that in the past 15 years a certain cyclicity of the pertussis disease has been observed with periods of reduction of the incidence of the disease to a significant increase. At the same time, in recent years there has been a tendency towards an increase in the incidence rate among children, with the incidence rate among the children of the vaccinated children being at a rather high level and is 51.4%. Children more than 1 year are more vulnerable. It is likely that an increase in the proportion of children under one year in the structure of the disease is due to the lack of transplacental transmission of antibodies, incomplete course of vaccination against pertussis, unformed postvaccinal immunity and, moreover, an increase in the incidence of disease among older children, which can be considered as a potential source of infection for children. infancy The increase in the incidence of pertussis in pre-school and school-age children is due to unreasonably broad contraindications to vaccination and the allegedly limited exposure of the current ACP vaccine to the epidemic disease process. It was revealed that the highest morbidity was observed in the autumnwinter-spring period, which is associated with an increase in the circulation of respiratory viruses, since it is known that pertussis in 24.5–60% of children is combined with acute respiratory viral infections. The decrease in the rate of vaccination against pertussis in the city of Sumy during the last 10 years has been shown, which reduces collective immunity, promotes the constant circulation of the causative agent among the children and influences the morbidity. In general, data on the epidemiological course of a pertussis in the city of Sumy repeats the course of the pattern of pertussis morbidity in Ukraine as a whole and in the world