Characteristics of extreme increase of vector-borne infections in the european north

Abstract

Aim. To describe clinical and epidemiological situation of the massive increase of cases of vector-borne infections and the level of preventive and antiepidemic measures in the Archangelsk region over the last decade. Methods. Retrospective, longitudinal study investigated ten-year incidence of vector-borne infections, vaccination of the population and the amount of disinfection measures in the region over the last decade. Results of a survey of 232 citizens, who were referred for vaccination against tick-borne encephalitis, are listed. The study included 101 patients with tick-borne encephalitis, 19 of which had concomitant a tick-borne Lyme disease, and 21 patients with tularemia treated in infectious hospitals of Archangelsk between 2011 to 2014. Results. Observations performed over the last decade showed marked increase in the incidence of vector-borne infections among the population of the Archangelsk region Levels of immunization against tick-borne encephalitis has also increased, level of vaccination against tularemia was unstable. Amounts of disinsectization measures tends to increase, but the number of people bitten by ticks also progressively increases. None of patients diagnosed with tick-borne encephalitis and tularemia who got the disease in the Archangelsk region had been previously vaccinated. The survey of 232 citizens showed sustainable motivation for vaccination, therefore, regional program for children and adult vaccination should be facilitated, considering the increasing incidence of vector-borne infections in non-vaccinated subjects. Predominant clinical forms were feverish and severe focal for tick-borne encephalitis, erythema for Lyme disease and bubonic for tularemia. Due to climate change, incidence of vector-borne infections over the last decade was on stable upward trend with high share of severe forms and high risk for progredient clinical course. Conclusion. Preventive and antiepidemic measures in the Archangelsk region over the last decade tend to increase, but are still not enough effective, as do not lead to a significant reduction of incidence.