Original scientific paper
Tick-Borne Encephalitis in the Area of Koprivnica-Križevci County – Prevalence and Spatial Distribution of those Affected in Settlements, in the Period from 1979 to 2011
Ljiljana Mišić–Majerus
; Dr. Tomislav Bardek General Hospital, Koprivnica, Croatia
Abstract
Koprivnica-Križevci County has been known as an endemic hotspot for tick-borne encephalitis (TBE) for the past 60 years, though it is certain that the disease was present here earlier. Special emphasis
was placed on examining the specificity of TBE and in gathering new knowledge about its epidemiology, clinical signs and diagnosing the disease, though many issues have remained unknown to the present day. The objective of this study was to show the prevalence and spatial distribution of patients with TBE by settlements, and to determine whether the prevalence and spatial distribution has changed over the course of the study. Over the period from 1979 to 2011, a total of 714 patients with TBE (599 adults and 115 children, aged 2 to 82 years) were treated at the Infective Diseases ward and Paediatric Ward of the Dr. Tomislav Bardek Clinical Hospital in Koprivnica. There were more
male than female patients and all patients were residents of the county, originating from 168 settlements. The average prevalence was one TBE patient per 162 residents in the county. Of the settlements, 57 had only one TBE patient, while the remaining 111 settlements had between 2 and 22 patients. The settlements with the highest number of patients to residents were: Dedina, Vinarec, Potok Kalnički, Selanec, Podvinje Miholečko, Karane, Sveta Ana, Brodić, Veliki Grabičani and Donji Maslarac. The highest numbers of patients in the investigated area originated from the settlements: Virje (22), Novigrad (20), Ferdinandovac (18), Molve (18), Hlebine (11), Rasinja (10), Dedina (20), Vinarec (16), Kalnički potok (13), Selanec (9) and Sveti Petar Čvrstec (9). One-fifth (19.6%) of all TBE patients lived in towns. Based on the collected data, significant changes were established in both
the prevalence and spatial distribution of TBE patients. In the first examined 11-year period, a total of 29.6 patients per year were examined, which decreased to 26.5 in the second 11-year period, and
decreased by more than three-fold in the third period. In examining the distribution of patients by place of residence, a pronounced drop in prevalence was observed for the Koprivnica area, with an increasing prevalence of the disease in settlements along the Drava River. Over time, several of the initially very “active” settlements, in terms of the disease, were “extinguished” over time, some occasionally or permanently remained “active”, while several new settlements have become active in recent years (e.g. Kloštar Podravski, etc.). The reason for such a significant drop in the incidence of TBE and changes in the spatial distribution of patients is difficult to explain. One possible explanation should be sought, due to the fact that diagnostic testing has been reduced due to the economic situation, that certain changes have been taking place in the lifestyle of the county’s inhabitants. Preventative measures that do not encompass the broader population (immunization programmes for TBE are aimed primarily risk groups of the population) cannot have a significant effect on the prevalence
of this disease. And while the majority of Europe’s endemic areas associate (with high significance) an increase in the prevalence and changes in spatial distribution of the disease with climatic changes,
primarily with increasing air temperature, these factors, though present, cannot be accountable for the changes observed in the territory of Koprivnica-Križevci County.
Keywords
tick-borne encephalitis; prevalence; spatial distribution by settlements; Koprivnica-Križevci County
Hrčak ID:
95374
URI
Publication date:
3.12.2012.
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