CHARACTERISTICS OF COVID-19 GROUP INCIDENCE SPREAD IN ORGANIZED COMMUNITIES IN THE KHABAROVSK KRAI DURING APRIL-SEPTEMBER OF YEAR 2020

During the observation period, total number of 31 epidemic cites with spread of COVID-19 in organized communities of the Khabarovsk region were registered. Epidemic analysis included evaluation of group incidence contribution in overall COVID-19 incidence, mean number of infected people in epidemic cites, indices of primary and secondary (including exposed people) incidence in epidemic cites on the expectation of 1000 exposed people, total percentage of COVID-19 clinical forms as well as their estimation for each type of epidemic cite. Statistical analysis was performed via STATISTICA 6.0. Software utilizing nonparametric techniques. Evaluation of epidemic significance of different types of epidemic cites was performed following the terms of evaluated criteria of epidemic process intensity. Pearson’s and Chi-squared test including Yates continuity correction if needed were estimated in order to assign ranks of the evaluated criteria. Mann-Whitney U-test was performed in order to rank mean duration of epidemic cites. Highest intensity of the epidemic process was revealed under conditions of COVID-19 clusters formation in social residential institutions that manifested with highest (mean for 1 epidemic cite) number of COVID-19 infected people, highest rates of primary and secondary (including exposed people) incidence in epidemic cites as well as longest mean duration of epidemic process. Indices of epidemic cites that were formed in medical facilities had high epidemic intensity but were lower than in social residential institutions. These criteria included high rates of overall COVID-19 incidence in epidemic cites (calculated for one COVID-19 cluster), registration of incidence among exposed people, fatal outcomes of the disease as well as substantial contribution of medical staff in COVID-19 overall group incidence registered in medical institutions of the region. Least intensity of epidemic process of COVID-19 group incidence was revealed in large industrial facilities and educational organizations where no spread of the disease was registered among exposed people as well as absence of lethal outcomes due to COVID-19. Percentage of acute respiratory infections in the structure of COVID-19 infected people was significantly higher in epidemic cites of educational communities.

Based on presented criteria of COVID-19 epidemic process intensity a differentiated approach towards application of preventive measures in epidemic cites of COVID-19 group incidence can be utilized. An intensified complex of constantly applied preventive measures against spread of new coronavirus disease is justified in the communities with high risk of COVID-19 spread where chances of outbreaks are high.

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