A major outbreak of hantavirus infection in Belgium in 1995 and 1996

Haemorrhagic fever with renal syndrome (HFRS) is a human disease characteri zed by flu-like symptoms, renal dysfunction, and in severe cases, haemorrha gic manifestations. The causative agents of HERS are Hantaan (HTN), Seoul ( SEO), Puumala (PUU) and Dobrava (DOB) hantaviruses. Hantavirus infections a re of increasing importance in Europe. Outbreaks occur in Belgium with a 3- to 4-year interval with an increasing number of cases. We describe the lar gest outbreak so far in Belgium with 217 serologically and clinically confi rmed cases in the period between October 1995 and December 1996. We demonst rated that the use of viral antigen derived from a local PUU-strain was abl e to detect significantly more sera positive for IgM in an immunofluorescen ce assay. Furthermore, although in some cases SEO, HTN and DOE antibody-rea ctivities were detected by ELISA, only PUU infections could be confirmed by neutralization test. The presence of an unknown hantavirus serotype circul ating in Belgium should be considered.