Disease burden of Puumala virus infections, 1995–2008

Abstract

SUMMARY: Puumala virus (PUUV) causes mild haemorrhagic fever with renal syndrome, a rodent-borne zoonosis. To evaluate the disease burden of PUUV infections in Finland, we analysed data reported by laboratories to the National Infectious Disease Registry during 1995–2008 and compared these with data from other national registries (death, 1998–2007; hospital discharge, 1996–2007; occupational diseases, 1995–2006). A total of 22 681 cases were reported (average annual incidence 31/100 000 population); 85% were in persons aged 20–64 years and 62% were males. There was an increasing trend in incidence, and the rates varied widely by season and region. We observed 13 deaths attributable to PUUV infection (case-fatality proportion 0·08%). Of all cases, 9599 (52%) were hospitalized. Only 590 cases (3%) were registered as occupational disease, of which most were related to farming and forestry. The wide seasonal and geographical variation is probably related to rodent density and human behaviour.