Small Mammals in Sweden as Hosts of Tick-Borne Encephalitis Virus and Vagrant Ectoparasites

A total number of 1234 small wild mammals of 11 different species were tested for the presence of neutralizing (NT) antibodies against tickborne encephalitis (TBE) virus. The infestation of the animals by ticks and fleas, particularly the recognized vector of the western type of TBE virus, Ixodes ricinus, was also recorded. The material was collected from areas with varying incidence of immune cattle, two areas known to be enzootic for TBE virus and another with a low frequency of infections with this virus. The frequencies of positive specimens from the endemic areas were 3 and 5 per cent, the positive individuals being found in 6 of 10 and 3 of 5 animal species, respectively. The corresponding figure for the low infectious area was I per cent and positive individuals were found in only I of 7 species. Animals from the endemic areas were infested to a higher degree with ticks and fleas than animals from the low infectious area. Pe3IoMe 1234 3K3eMniJIipa MeJIKHX RHKHX MJIeKon4TaiOiuX, npHHaajexalUX K 11 BHaaM, HcciiegoBaHO Ha HpHCYTCTBiHe HeATpaJ1H3YIOUU4X (N T) aHTHTfeI HpOTHB BHpyca Kiieiuesoro 3Hue4baJiHTa (TBE). KOHCTaTH~pOBaHO 3apaweHEe CKHBOTHBIX KJIeIuaMH H 6JIoxaMHi, B MaCTHOCTH, 3afaaHbIl4 THUI BHpyca TBE nepeJgaeTcA qIepe3 Ixodes ricinus. MaTeplIan 6BEI co6paH c y'aCTKOB C pa3JIHMHbIM KOJIHIeCTBOM HMYHHBIOX XHBOTHbIX, IlpHqeM H3BeCTHO, 'TO 2 y'iacTKa RBJIqIOTCq 3H300THqH]MM6 )YI$A BHpyca TBE, a Ha apyrHx 'laCTOTa 3apawKeHHOCTH 3THM BHpYCOM HH3Ka. KOJIH'IeCTBO oco6erl c HOJIOWKHTeJn1HOA peaKUHeiI Ha 3HJeMHllHbIX yqaCTKax COCTaBJIReT 3 % H 5 %, KOJIH'eCTBO Bh4ROB C nOJIO)KHTeJIbHOA peaKuLeg Ha 3THX y'aCTKaX COOTBeTCTBeHHO 6 113 10 H 3 113 5. 4jim apyr~x y'laCTKOB 3apa)KeHHOCTbO COCTaBJIqeT 1 % Y XKHBOTHBIX OaHorO BHaa (113 HCCJ1ieaOBaHHbIX 7 BHaOB). )KHBOTHbIe Ha 3HaeMHH6IbX yqaCTKax 3apawaKaOTCA 'epe3 KJiewerl H 6jiox B 6onmImierl CTeCeHH, xieM Ha yqaCTKaX C HH3KOUl 3apa)KeH-