A case-control study after a hantavirus infection outbreak in the South ofBelgium: Who is at risk?

Puumala is the most common hantavirus serotype in Europe and is spread main ly by the red bank vole. Between 1 July 1992 and 31 January 1994, an outbre ak of Puumala virus-induced nephropathia epidemica (NE) occurred in the Bel gian Ardennes. Serologically confirmed cases (n = 41) sere compared with tw o groups of asymptomatic seronegative controls. Risks identified included s ighting of living rodents, exposure to rodent droppings, and trapping roden ts during the 4 necks preceding onset of symptoms. Activities during this 4 -week period that presented the greatest risk were woodcutting, reopening o f a nonaerated room, and strenuous physical effort. This is the first case- control study on risk factors for NE in Europe. In comparison with the Amer ican form of hantavirus pulmonary syndrome, which is spread by deer mice, p rofessional activity appears to be a more important risk factor for acquisi tion of hantavirus in Europe.