OCCUPATIONAL RISKS OF ZOONOTIC INFECTIONS IN DUTCH FORESTRY WORKERS AND MUSKRAT CATCHERS

Lyme borreliosis (LymeB), Hemorrhagic fever with renal syndrome (HemoF RS), Lymphocytic choriomeningitis (LymphoCM), Tick-borne encephalitis (TickBE), Q Fever (QFever), and Well's leptospirosis (Lepto) are known to be occupational diseases for rural outdoor workers. We investigate d the occupational infection risks for these diseases in greater detai l. Antibodies to these agents were assessed in 312 forestry workers an d muskrat catchers, and in 356 matched office workers. Three levels of occupational exposure were distinguished: high for active forestry wo rkers, low for supervisory forestry staff and muskrat catchers and zer o for office workers. At high exposure the prevalence odds ratios (wit h 95% CI between brackets) were: LymeB 15 (5.5-42), HemoFRS 11 (1.3-50 1), LymphoCM 5.4 (1.0-50), TickBE 1.0 (0.3-3.0), QFever 1.0 (0.4-2.1), and Lepto 0 (0.0-33). No significant risk of infection was found at l ow exposure. Part of the present group had also been studied in 1989 a nd 1990. Within this cohort the conversion rates to Borrelia burgdorfe ri have been estimated for the periods 1989-1990 and 1990-1993 as 0.23 and 0.066 year(-1), respectively, and the reversion rate as 0.44 year (-1). The corresponding values for HemoFRS were 0.031, 0.018 and 1.42 year(-1). Active forestry workers in the Netherlands are at high risk of infection by LymeB, HemoFRS and LymphoCM. Prevalence of antibodies to LymeB and HemoFRS appeared to reflect the levels of these infection hazards in recent history.