[Arbovirus infections in Spain: serological survey on small mammals]

Sera of 386 small mammals (rodents, insectivora, small carnivora and cheiroptera) trapped in Spain in 1978 and 1979 were studied for antibody against 10 arboviruses. Positive reactions were found against flaviviruses: West Nile (3.1%), dengue type 2 (0.5%), tick-borne encephalitis, European type (0.2%), together with Tahyna (6.5%), Uukuniemi (2%) and Bhanja (1%) viruses. The animal species concerned by positive reactions were essentially Mus spretus and Apodemus sylvaticus which were also the more numerous species trapped during the survey. In addition, in Crocidura russula, an unique reaction against West Nile virus was found. Results of our serosurvey in small mammals correlated well with those of previous reports in men or animals, from Portugal and from north-western Spain.