Department of Virology, Karolinska Institute, c/o National Bacteriological Laboratory, National Defense Research Establishment, Department of Infectious Diseases, Sundsvall County Hospital, Departments of Infectious Diseases, Virology, and Animal Ecology, University of Umea, Hemorrhagic Fever Laboratory, Institute of Poliomyelitis and Viral Encephalitides, Academy of Medical Sciences, Stockholm, Sweden
The incidence and antibody prevalence of hemorrhagic fever with renal syndrome (HFRS) in Bashkirtostan (European part of Russia) and northern Sweden was compared with the abundance of Clethrionomys glareolus (bank voles) in the two areas. In Bashkirtostan, 10% of the women and 15% of the men were found to be antibody positive. The corresponding figures for Sweden were 8% and 16% for women and men, respectively. The annual incidence of HFRS in Bashkirtostan was 50 cases per 100,000 inhabitants, with a male:female ratio of 4.6:1. The incidence in the endemic area of Sweden was seven cases per 100,000 inhabitants, with a male:female ratio of 1.8:1. A similar age distribution of cases, with a peak in the middle age groups, especially in men, was found in both Bashkirtostan and Sweden. The incidence of HFRS in humans and the abundance of bank voles varied with time in both Bashkirtostan and Sweden, but the study failed to find any significant correlation between the two variables. The study showed that HFRS causes significant human morbidity in the areas studied but that both incidence and possibly bank vole abundance was higher in Bashkirtostan than in northern Sweden.