Table 1 Summary of published and unpublished data on I. ricinus ticks collected in Sweden, Norway, Finland and Denmark analysed for TBE virus infection
| Â | Â | Â | Number of collected ticks | Number of TBEV-positive | Prevalence estimate (%) | Â | Â | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Country | Collection year | Locality | Nymphs | Males | Females | Total | Pools | Positive pools | Positive nymphs | Positive adults | MIR nymphs | MIR adults | MIR all | Method | Reference |
Sweden | 1958 | 96Â km NE of Stockholm (9 sites) | 35 | 898 | 933 | 24 | 4 | 1 | 3 | 2.86 | 0.33 | 0.42 | MBI* | [43] | |
Sweden | 2003 | Torö | 106 | 9 | 115 | 1 | 1 | – | – | – | – | 0.87 | RT-PCR | [17] | |
Sweden | 2003 | Combined central Sweden (3 sites) | 167 | 23 | 190 | 1 | 1 | – | – | – | – | 0.53 | RT-PCR | [17] | |
Sweden | 2006 | 3 sites south of Vänern (T1-T3) | 4380 | 220 | 220 | 4820 | 263 | 11 | 9 | 2 | 0.21 | 0.45 | 0.23 | RT-PCR | [29] |
Sweden | 2004 | South-western Sweden (T4) | 2740 | 70 | 2810 | 144 | 7 | 6 | 1 | 0.22 | 1.43 | 0.25 | RT-PCR | [29] | |
Sweden | 2008 | Hudiksvall (1) | 30 | 6 | 5 | 41 | 14 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Stenö/Källskär (2) | 300 | 90 | 92 | 482 | 202 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Gävle (3) | 4 | 1 | 0 | 5 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Trödje (4) | 3 | 2 | 2 | 7 | 4 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Skutskär (5) | 29 | 11 | 15 | 55 | 27 | 1 | 0 | 1 | 0 | 3.85 | 1.82 | RT-PCR | This study |
Sweden | 2008 | Älvkarleby (6) | 10 | 6 | 13 | 29 | 20 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Borlänge (7) | 7 | 4 | 4 | 15 | 9 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Vikmanshyttan (8) | 15 | 2 | 4 | 21 | 7 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Östhammar (9*) | 94 | 10 | 15 | 119 | 31 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Norbo Finnmark (10) | 11 | 11 | 12 | 34 | 24 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Väddö (11*) | 32 | 10 | 6 | 48 | 18 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Skebobruk (12*) | 40 | 13 | 19 | 72 | 34 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Morga (13*) | 300 | 31 | 55 | 386 | 114 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Rimbo (14*) | 8 | 2 | 4 | 14 | 7 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Kapellskär (15*) | 373 | 59 | 70 | 502 | 151 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Kolarvik (16*) | 158 | 57 | 49 | 264 | 115 | 1 | 1 | 0 | 0.63 | 0 | 0.38 | RT-PCR | This study |
Sweden | 2008 | Västerås (17*) | 137 | 11 | 24 | 172 | 47 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Strängnäs (18*) | 37 | 27 | 22 | 86 | 51 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Eskilstuna (19*) | 27 | 4 | 7 | 38 | 13 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Karlstad (20) | 9 | 5 | 3 | 17 | 9 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Värmdö (21*) | 46 | 3 | 6 | 55 | 16 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Askersund (22) | 36 | 0 | 5 | 41 | 9 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Herrhamra (23*) | 196 | 31 | 36 | 263 | 99 | 4 | 1 | 3 | 0.51 | 4.48 | 1.52 | RT-PCR | This study |
Sweden | 2008 | Kapellängen, GS (24) (P) | 24 | 21 | 2 | 47 | 25 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Gamla gården, GS (25) (P) | 5 | 2 | 2 | 9 | 4 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Jönköping (26) | 30 | 2 | 1 | 33 | 5 | 1 | 0 | 1 | 0 | 33.33 | 3.03 | RT-PCR | This study |
Sweden | 2008 | Västervik (27) | 14 | 4 | 5 | 23 | 10 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Änggårdsbergen (28) | 31 | 0 | 1 | 32 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Särö Västerskog (29) (P) | 68 | 0 | 2 | 70 | 8 | 0 | 0 | 0 | 0 | 0 | 0 | RT-PCR | This study |
Sweden | 2008 | Combined central Sweden, 12 sites* | 1448 | 258 | 313 | 2019 | 258 | 5 | 2 | 3 | 0.14 | 0.53 | 0.25 | RT-PCR | This study |
Sweden | 2008 | Combined Sweden, 29 sites | 2074 | 425 | 481 | 2980 | 1074 | 7 | 2 | 5 | 0.10 | 0.55 | 0.23 | RT-PCR | This study |
Sweden | 1958–2008 | Combined Sweden, 4 studies, 45 sites | 9396 | 2337 | 11733 | 1510 | 30 | 18 | 11 | 0.19 | 0.47 | 0.26 | */PCR | ||
Finland | 1957–1960, 1964 | Archipelago of southern-western Finland | 4932 | 391 | 389 | 8131 | 249 | 18 | – | – | – | – | 0.22 | MBI** | [44] |
Finland | 1957-1960, 1964 | Southern Finland | 124 | 9 | 0 | 133 | 7 | 0 | – | – | – | – | 0 | MBI** | [44] |
Finland | 1957–1960, 1964 | South-eastern Finland | 1308 | 39 | 84 | 1643 | 51 | 1 | – | – | – | – | 0.06 | MBI** | [44] |
Finland | 1996–1997 | Isosaari (Mjölö) island, Helsinki | 69 | 70 | 139 | 20 | 1 | – | – | – | – | 0.72 | RT-PCR | [45] | |
Finland | 1996–1997 | Åland islands | 203 | 247 | 450 | 48 | 1 | – | – | – | – | 0.22 | RT-PCR | [45] | |
Finland | 1996–1997 | Helsinki city parks | 74 | 123 | 726 | 130 | 0 | – | – | – | – | 0 | RT-PCR | [45] | |
Finland | 2004 | Kokkola (Karleby) archipelago (10 sites) | 72 | 539 | 570 | 1181 | 122 | 13 | – | – | – | – | 1.10 | RT-PCR | [13] |
Finland | 2003 | Kumlinge | – | – | – | 454 | 46 | 4 | – | – | – | – | 0.88 | RT-PCR | [21] |
Finland | 2005 | Isosaari (Mjölö) island, Helsinki | – | – | – | 96 | 11 | 1 | – | – | – | – | 1.04 | RT-PCR | [21] |
Finland | 2007 | Turku (Åbo) archipelago | – | – | – | 1039 | 315 | 1 | – | – | – | – | 0.10 | RT-PCR | [21] |
Finland | 2005 | Lappeenranta (Villmanstrand) | – | – | – | 292 | 29 | 2 | – | – | – | – | 0.68 | RT-PCR | [21] |
Finland | 2008 | Närpiö (Närpes) | – | – | – | 36 | – | 0 | – | – | – | – | 0 | RT-PCR | [21] |
Finland | 1957–2008 | Combined Finland, 4 studies, ≥ 27 sites |  |  |  | 14320 | 2490 | 42 | – | – | – | – | 0.29 | **/PCR | |
Norway | 2003 | Vest-Agder and Hordaland county | 360 |  |  | 1 | – | – | – | – | 0.28 | RT-PCR | [19] | ||
Norway | 2004 | Vest-Agder and Hordaland county | 450 |  |  | 1 | – | – | – | – | 0.22 | RT-PCR | [19] | ||
Norway | 2009 | Risør, Dalen (S1) | 900 | – | – | 900 | 90 | 1 | 1 | – | 0.11 | – | 0.11 | RT-PCR | [46] |
Norway | 2009 | Arendal (S2–S3) | 1350 | – | – | 1350 | 135 | 8 | 8 | – | 0.59 | – | 0.59 | RT-PCR | [46] |
Norway | 2009 | Mandal (S4–S5) | 1520 | – | – | 1520 | 152 | 9 | 9 | – | 0.59 | – | 0.59 | RT-PCR | [46] |
Norway | 2009 | Lyngdal (S6–S7) | 1860 | – | – | 1860 | 186 | 6 | 6 | – | 0.32 | – | 0.32 | RT-PCR | [46] |
Norway | 2003–2009 | Combined Norway, 2 studies, 9 sites |  |  |  | 6440 | ≥ 563 | 26 | – | – | – | – | 0.40 | RT-PCR | |
Denmark | 1999 | Bornholm (7 sites) | 3843 | 215 | 4058 |  | 2 | – | – | – | – | 0.05 | RT-PCR | [47] | |
Denmark | 2002–2003 | Northern Zealand | 50 | 25 | 30 | 105 | 3 | 1 | 1 | – | 2.00 | – | 0.95 | RT-PCR | [48] |
Denmark | 2002–2003 | 3 different sites | 62 | 62 | 9 | 0 | – | – | – |  | – | RT-PCR | [48] | ||
Denmark | 2011 | Tokkekøb (3 sites, Jun.) | 854 | 22 | 20 | 896 | 24 | 3 | 2 | 1 | 0.23 | 2.38 | 0.33 | RT-PCR | [20] |
Denmark | 2011 | Tokkekøb (3 sites, Sept.) | 700 | 15 | 15 | 730 | 8 | 5 | 5 | 0 | 0.71 | – | 0.68 | RT-PCR | [20] |
Denmark | 2011 | Grib Forest | 183 | 9 | 6 | 198 | 13 | 0 | 0 | 0 | – | – | – | RT-PCR | [20] |
Denmark | 2011 | Bornholm (3 sites) | 738 | 37 | 41 | 816 | 13 | 0 | 0 | 0 | – | – | – | RT-PCR | [20] |
Denmark | 1999–2011 | Combined Denmark, 3 studies , ≥ 18 sites |  |  |  | 6865 | ≥ 70 | 11 | – | – | – | – | 0.16 | RT-PCR | |
All four countries | 1957–2011 | All sites (≥ 99) included in references |  |  |  | 39358 | 3171 | 109 |  |  |  |  | 0.28 |  | |