OUTBREAKS OF CLINICAL CEREBROSPINAL ELAPHOSTRONGYLOSIS IN REINDEER (RANGIFER-TARANDUS-TARANDUS) IN FINNMARK, NORWAY, AND THEIR RELATION TO CLIMATIC CONDITIONS

Outbreaks of clinical cerebrospinal elaphostrongylosis (CSE) in reindeer (Rangifer tarandus tarandus) in Finnmark county, northern Norway, were summarized for the period 1960-1993 and compared to meteorological data. Disease outbreaks occurred during autumn and winter of seven different years. They were highly associated with high temperatures and moderately associated with heavy rainfall during the preceding summers. Mean summer temperatures for years with and without subsequent disease outbreaks were 1.5-degrees-C above and 0.4-degrees-C below the overall mean for the observation period. Summer temperatures above mean seem to be required to induce the mass development of infective Elaphostrongylus rangiferi larvae in the intermediate gastropod hosts that subsequently leads to severe infection and clinical CSE in reindeer in Finnmark. After hot summers, the nematode may cause epidemics with heavy losses, especially among calves.