Arteaga 199837 | Cross sectional, 1998† | Vizcaya, Spain | 302 Outdoor workers (117 forestry, 52 large animal vets, 18 shepherds, 27 apiculturists, 74 mushroom and truffle gatherers, 14 other) v none | ELISA, WB (CDC criteria for serological reactivity), and self reported clinical questionnaire. | Seroprevalence outdoor workers = 15% (44/302) by WB |
| Cumulative clinical prevalence, outdoor workers = 15% (11/44) by WB |
Baird 198942 | Cross sectional, 1989† | Wigtownshire, UK | 101Samples from farmers, foresters, and gamekeepers and seven samples from patients with potential LD v none | IFA, ELISA and physician diagnosis | Seroprevalence = 11% (12/108) |
| | | | | Cumulative clinical prevalence = 91% (11/12) |
Bowen 198448 | Prospective, 1978–82 | Monmouth County, NJ, USA | 366 Outdoor workers at naval weapons station v 766 indoor workers at naval weapons station | IFA, clinical interview and medical record review | Incidence outdoor workers = 3.8% (14/366) |
| | | | | Incidence indoor workers = 0.8% (6/766), p<0.001 |
Chmielewska-Badora 199836 | Cross sectional, 1998† | Lublin, Poland | 1153 Workers exposed to ticks (880 forestry workers and 273 farmers), 458 patients suspected of LD (362 from neurological clinic and 96 from dermatologic clinic) v 100 healthy blood donors | IFA, ELISA and physician diagnosis | Seroprevalence farmers = 38.6% |
| | | | | Seroprevalence foresters = 28.1% |
| | | | | Seroprevalence blood donors = 6%, p<0.001 |
| | | | | Cumulative clinical prevalence farmers/foresters = 0.0% (1/1153) |
Christiann 199621 and Christiann 199757 | Case-control with control data supplemented from Christiann 1997 | Berry, France | 59 Cases of Lyme disease among the residents of Berry Sud (Christiann 1996); 170 recreational hunters v 182 blood donors (Christiann 1997) | IFA or ELISA until Nov 1993 and then ELISA only; clinical examination and WHO recommendations 1993 and CDC criteria 1990 | 58% (34/59) Of LD cases were among farmers |
| | | | | Seroprevalence hunters = 15% (25/170) |
| | | | | Relative risk of seroreactivity hunters v blood donors = 1.79, p=0.00001 |
Fahrer 199840 | Phase II, prospective, 1986–88 and 1993 | Switzerland | Phase II, 305 seropositive orienteers reexamined v phase I, 950 orienteers | ELISA, self reported clinical questionnaire, physician diagnosis and medical record review. | Annual clinical incidence phase II orienteers = 0.8% |
| | | | | 6 Month clinical incidence phase I orienteers = 0.8% |
| | | | | Cumulative clinical prevalence phase II orienteers = 4.9% (15/305) |
Fahrer 199141 | Phase I of Fahrer 1998, prospective, 1986 | Switzerland | 950 Swiss orienteers v 51 healthy volunteers who had spent most of their life at altitudes >1000 m and 50 inhabitants of Berne at altitude 500 m‡ | ELISA, self reported questionnaire, physician diagnosis and medical record review. | Cumulative clinical prevalence orienteers = 1.9%–3.1% |
| | | | | Seroprevalence orienteers = 26.1% |
| | | | | Seroprevalence high altitude = 3.9% (2/51) |
| | | | | Seroprevalence Berne = 6.0% (3/50) |
| | | | | Six month clinical incidence orienteers = 0.8% |
Goldstein 199049 | Cross sectional, Oct 1998 | New Jersey, USA | 689 Employees from the NJ Natural and Historic Resources Section from 12 different sites v none | IFA, ELISA, and self reported clinical questionnaire | Seroprevalence = 5.7% (39/689) by IFA or ELISA |
| | | | | There was no association between seropositivity and job title or job habitat |
Golubic 199819 | Case series, 1998† | Croatia | 218 Cases of LB in NW Croatia v none | IFA, self reported questionnaire, physician diagnosis and medical record review. | Clinical prevalence according to occupation: student 15% (33/218), agricultural worker 30% (30/218), agricultural clerk 14% (32/218), pensioner 12.5% (27/218) and housewife 14% (30/218) |
Gregory 199343 | Case series, 1987–91 | UK | Two cases of neuroborreliosis and 6 more reports of clinical LD with positive ELISA v none | ELISA and physician diagnosis | 2 Case reports of neuroborelliosis and six case reports of LD among military personnel in the UK |
Gustafson 199339 | Cross sectional, Oct 1990 | Stockholm, Sweden | 362 Orienteers from the county of Stockholm during a large relay race in October 1990 | ELISA, self reported clinical questionnaire and physician diagnosis | Seroprevalence orienteers = 9% (31/362) |
| | | | | Seroprevalence controls = 2% (A-1/50), 9% (B-13/150), 1% (C-1/74), 2% (D-9/378) |
| | | A - 50 Blood donors | | Seroprevalence OR orienteers v control B = 0.9 (95% CI 0.5 to 1.8) |
| | | B - 150 People living in Sweden (no orienteers) | | Seroprevalence OR orienteers v control C = 9.3 (95% CI 3.6 to 24.2) |
| | | C - 74 Hospital patients | | Cumulative clinical prevalence orienteers = 6% (22/362) |
| | | D - 378 People from Iceland (no Ixodes ticks) | | Cumulative clinical prevalence controls-B = 1% (2/150), OR = 4.8 (95% CI 1.1 to 20.6) |
Guy 198944 | Cross sectional, 1989† | Southampton, UK | 41 Forestry Commission workers (11 keepers, 30 other) v none | ELISA, WB and self reported clinical questionnaire | Seroprevalence = 25% (10/40) by WB |
| | | | | Cumulative clinical prevalence = 5% (2/40) |
Hauser 199823 | Case control, 1989–95 | Germany | 222 Patients with clinically defined LB and 458 asymptomatic forestry workers v 133 blood donors | ELISA and physician diagnosis | Seroprevalence foresters = 41–44.8%, depending on ELISA antigen. |
| | | | | Seroprevalence blood donors = 8%, OR = 8.4 (95% CI 4.4 to 15.9) |
Ikushima 199928 | Cross sectional, 1999† | Japan | 80 Forestry workers v none | ELISA and WB | Seroprevalence foresters = 22.5% (18/80) by WB |
Klein 199550 | Case series, 1995 | Wilmington, DE, USA | Five physicians among 83 employed pediatricians and 55 pediatric residents v none | Physician diagnosis | One year clinical prevalence physicians = 3.6% (5/138) |
Kuiper 199332 | Prospective, 1989–90 | Netherlands | 151 Dutch forestry workers v 151 male office workers matched for age and residence | ELISA, WB, and physician diagnosis with reference to CDC case definition, 1990 | Seroprevalence forestry = 28% (43/151) by ELISA |
| | | | | Seroprevalence office = 5% (8/151) by ELISA, p<0.01 |
| | | | | Clinical incidence forestry = 0.0% |
| | | | | Seroconversion forestry = 5% by ELISA/WB |
| | | | | 18% (7/39) Of seropositive forestry workers or 5.5% (7/127) of all forestry workers in 1989 met the case definition criteria for LB. |
Kuiper 199131 | Cross sectional, 1989 | Netherlands | 127 Dutch forestry workers v 127 male office workers, matched for age and region | IFA, WB and physician diagnosis (adapted CDC classification) | Seroprevalence foresters = 19.7% (25/127) |
| | | | | Seroprevalence office = 6.3% (8/127), OR = 3.7, 95% CI 1.5 to 9.7. |
| | | | | Cumulative clinical prevalence foresters = 6% (7/127) |
Lane 199251 | Prospective, 1988–89 | Northwest California | 119 Residents of Mendocino County at entry (99 current and 20 former residents) and 59 at follow up v none | IFA, WB and physician diagnosis | Seropositivity was associated with greater years of residence in the area (p=0.032), decreased hiking (p=0.006), and woodcutting (p=0.048). |
| | | | | Time spent working outdoors was not identified as a risk factor for probable LD. |
Ley 199552 | Case control, June 1991–Dec 1992 | California | All cases of EM reported to CA Department of Health Services v age and sex matched controls | Physician diagnosis | Diagnosis of LD was not associated with work outdoors, OR = 1.04 (p=0.87) or total number of hours spent outside during leisure activities per month. |
Montejunas 199430 | Prospective, 1988–91 | Lithuania | Three occupational groups: foresters (n=268), outside field workers (n=115), and veterinarians (n=68) v 163 urban industrial workers | IFA | Seroprevalence foresters = 14% (37/268) |
| | | | | Seroprevalence field = 22% (25/115) |
| | | | | Seroprevalence vets = 32% (22/68) |
| | | | | Seroprevalence urban = 4% (6/163), OR = 2.5, p<0.001 |
Morgan 198945 | Cross sectional, 1989 | UK | 180 Farmers and their familes v 75 control patients who lived in the area, but who denied contact with farm animals | ELISA | Seroprevalence farmers/families = 14.4% (26/180) |
| | | | | Seroprevalence control = 2.6% (2/75) |
Nakama 199429 | Cross sectional, 1990–91 | Nagano, Japan | 222 Forestry workers v 760 residents of an agricultural town | IFA | Seroprevalence foresters = 1.1% (8/760) |
| | | | | Seroprevalence residents = 5.9% (13/222), p<0.01 |
Nuti 199326 | Cross sectional, 1987–91 | Italy | 1146 Subjects subdivided into six categories: farmers (395), forestry workers (265), rangers (82), soldiers (299), hunters (75) and fishermen (30) v none | IFA | Seroprevalence farmers = 10.1% (40/395) |
| | | | | Seroprevalence foresters = 19.6% (52/265) |
| | | | | Seroprevalence rangers = 19.5% (16/82) |
| | | | | Seroprevalence soldiers = 3.0% (9/299) |
| | | | | Seroprevalence hunters = 8.0% (6/75) |
| | | | | Seroprevalence fisherman = 16.6% (5/30) |
Oksi 199520 | Prospective, Jun 1993–Dec 1993 | Gylto, Finland | 77 Military recruits in Lyme endemic area initially, 67 recruits completed the study at 6 months v 50 military recruits in nonendemic area, initially; 33 recruits completed the study at 6 months. | ELISA and self reported clinical questionnaire | No probable history of EM in either group. |
| | | | | Seroprevalence military endemic = 16.9% (13/77) |
| | | | | Seroprevalence military nonendemic = 4.0% (2/50) |
| | | | | No change in IgG seroprevalence at 6 month follow up for either group. |
Oteo 199238 | Cross sectional, Oct 1986–Mar 1988 | La Rioja, Spain | 500 Non-randomised individuals residing in Rioja, Spain v none | IFA and self reported clinical questionnaire | Seroprevalence outdoor worker = 20% v other 4.7%, p<0.001 |
| | | | | Seroprevalence was associated with rural residence, p<0.001 |
| | | | | Seroprevalence was associated with foresters, cattle raisers, and contact with domestic animals, p<0.001 |
| | | | | 28% of farmers/foresters showed clinical signs compatible with LD |
Parrott 19937 | Prospective, May 1989–Oct 1989 | Assateague Island, MD | 99 Outdoor workers on Assateague Island initially with 86 workers continuing to post seasonal evaluation v None | ELISA and self reported clinical questionnaire | Seroprevalence = 0% |
| | | | | Seroconversion 3 month follow up = 0% |
| | | | | Clinical prevalence = 0% |
Rath 199624 | Prospective, Feb–Sep 1992 | Brandenburg, Germany | 626 Foresters initially, 406 foresters at 6 month follow up v 200 blood donor controls | IFA, IBA, and self reported clinical questionnaire | Seroprevalence foresters = 8% by IBA |
| | | | | Seroprevalence controls = 4% by IBA, p<0.05 |
| | | | | Seroconversion foresters, 6 month follow up = 7.2% (IBA) |
Reese 199446 | Cross sectional, 1993 | London, UK | 44 Outdoor park workers from Richmond and Bushey parks v 27 zoo keepers from Whipsnade wildlife park in Bedfordshire, who worked in a similar outdoor environment | ELISA, IBA and self reported clinical questionnaire | Seroprevalence park = 32% (14/42) by IBA (three bands) |
| | | | | Seroprevalence zoo = 4% (1/27) by IBA (three bands), p<0.005 |
Robertson 199825 | Cross sectional, 1998† | Ireland | 38 National park rangers v 1224 blood donors from the same location as the park rangers | ELISA and IBA (5 bands present) | Seroprevalence park rangers = 0% (0/22) by IBA |
| | | | | Seroprevalence blood donors = 3.4% (42/1224) by IBA |
Santino 199827 | Cross sectional, Jun–Aug 1995 | Abruzzo, Italy | 22 Park workers at an altitude of 750 to 1150 m v 50 park inhabitants at an altitude of 1150 m‡ | ELISA, WB, and self reported clinical questionnaire | Seroprevalence park rangers = 9.1% (2/22) by ELISA, altitude = 800 m, 1080 m |
| | | | | Seroprevalence park rangers = 4.5% (1/22) by WB (5 bands), altitude unknown |
| | | | | Seroprevalence park inhabitants = 0.0% by ELISA, altitude = 1150 m |
| | | | | None of the park workers or inhabitants showed signs compatible with LD. |
Schmutzhard 198818 | Cross sectional, 1985 | Tyrol, Austria | 80 Austrian Federal Army soldiers intially, 50 soldiers at 4 week follow up (serology) and clinical observation for 14 weeks v none | ELISA and physician diagnosis | Seroprevalence initially = 11% (9/80) |
| | | | | Seroprevalence at 4 week follow up = 38% (18/50) |
| | | | | Seroconversion = 22% (11/50) |
| | | | | Clinical prevalence at 14 week follow up = 4% (2/50) |
Schwartz 19909 | Cross sectional, Sep–Oct 1988 | NJ, USA | 689 Employees of NJ State Dept. of Env. Protection, included both indoor and outdoor workers v subset of indoor workers | IFA, ELISA, and self reported clinical questionnaire | Seroprevalence indoor/outdoor workers = 5.7% (39/689) |
| | | | | Crude OR associated with occupational tick exposure = 2.2 (95% CI 0.7 to 9.0). |
| | | | | Adjusted OR associated with occupational tick exposure = 5.1 (95% CI =1.1 to 23.6). |
Schwartz 199353 | Cross sectional, Oct 1990 | NJ, USA | 758 Employees of NJ State Dept. of Env. Protection Outdoor workers v none | ELISA and self reported clinical questionnaire | Seroprevalence outdoor, 1988 = 8.1% |
| | | | | Seroprevalence outdoor, 1990 = 18.7% (142/758) |
| | | | | LD incidence in the general population increased 30% from 1989 to 1991 |
Schwartz 199454 | Prospective, 1988–91 | NJ, USA | NJ outdoor workers from Dept. of Env. Protection; 1519 workers for at least 1 y, 378 workers for 2 y, 228 for 3 yrs, and 192 for 4 years v none | IFA in 1988 and then ELISA from 1989 to 1991; and self reported clinical questionnaire | Seroprevalence outdoor = 4.4 to 18.7% |
| | | | | Seroconversion outdoor = 0.6 to 16.7% |
| | | | | Seroreversion outdoor = 23 to 53% |
| | | | | Risk factors for seroconversion included years at residence, rural residence, pet ownership, and a history of medical problems. |
Smith 198855 | Cross sectional, May–Nov 1986 | NY, USA | 414 State employees of the NY State Office of Parks, Recreation and Historic Preservation and of the NY State Department of Environmental Conservation v 362 NY State blood donors in Lyme endemic area and NY State blood donors in non Lyme endemic area, total number unknown | ELISA, WB and self reported clinical questionnaire | Seroprevalence state employees = 6.5% (27/414) |
| Seroprevalence Lyme endemic controls = 1.1% (4/362) |
| | | | | Seropositivity RR state employees v Lyme endemic controls = 5.9 (95% CI 2.4 to 14.6) |
| | | | | RR seropositivity outdoor worker v indoor worker = 2.0 (95% CI 0.3 to 13.0). |
| | | | | Seropositivity was associated with leisure time outdoor exposure, while the evidence for an association with work exposure was less consistent. |
| | | | | Hours spent outdoors during work was not associated with seropositivity. |
Stanchi 199317 | Case control, 1993 | Argentina | 28 Farmers referred by physicians for arthritis v 25 farmers without past or present arthritis | IFA | Seroprevalence farmers with arthritis = 11% (3/28) |
| | | | | Seroprevalence farmers without arthritis = 0% (0/25) |
Thomas 199847 | Prospective, 1991 to 96 | UK | 404 Farmers and their families at enrollment; 387 at 1 year; 345 at 2 years; and 336 at 3 years v None | ELISA, WB and self reported clinical questionnaire | Seroprevalence enrollment = 0.2% (1/404) by WB |
| | | | | Seroreversion = 0.3% (1/387) |
| | | | | Seroconversions = None |
Van Charante 1998;33 Follow up of Van Charante 199434 | Prospective, 1989 to 93 | Netherlands | 312 Forestry workers and muskrat catchers stratified according to high or low exposure v 356 office workers with no exposure | ELISA, WB self reported clinical questionnaire | Seroprevalence OR high exposure foresters/muskrat v office workers = 17 (95% CI 6.4 to 55) |
| | | | | Seroprevalence OR low exposure foresters/muskrat v office workers = 6.1 (95% CI 2.9 to 13) |
| | | | | Seroconversion = 0.23 year−1 (95% CI 0.12 to 0.34) |
Van Charante 199434 | Prospective, 1989 to 90 | Netherlands | 151 Forestry workers v 151 office clerks | ELISA, self reported clinical questionnaire | Seroprevalence forester = 19.9% (30/151) |
| | | | | Seroprevalence office = 6% (9/151) |
| | | | | Seroprevalence OR foresters v office = 3.9 (95% CI 1.7 to 9.7) |
Vos 199435 | Prospective, Jan to Dec 1991 | Netherlands | Initially, 905 outdoor military recruits. After 1 year 469 recruits for second blood draw v Initially, 1253 indoor military recruits. After 1 year 463 for follow up | ELISA, WB, self reported clinical questionnaire and physician diagnosis | Seroconversion indoor = 0.9% (4/469) |
| Seroconversion outdoor = 2.2% (10/463) |
| | | | | Seroconversion RR outdoor v indoor = 0.4 (95% CI 0.1 to 1.2) |
| | | | | Clinical incidence among seroconverted outdoor = 7.1% (1/14) |
| | | | | Clinical incidence among seroconverted indoor = 0.0% (0/10) |
Zhioua 199722 | Cross sectional, 1997 | France | 212 Forestry workers v 31 blood donors with no contact with the forest | IFA and physician diagnosis | Seroprevalence forester = 15.2% (32/211) |
| | | | | Seroprevalence blood donor = 3.2% (1/31) |
| | | | | Seropositivity OR forester v blood donor = 5.4 (95% CI 0.7 to 40.7) |
| | | | | Cumulative clinical prevalence forester = 3.3% (7/211) |