High coronavirus incidence has prompted the Netherlands to implement a second lockdown. To elucidate the epidemic’s development preceding this second wave, we analysed weekly test positivity in public test locations by population subgroup between 1 June and 17 October 2020. Hospitality and public transport workers, driving instructors, hairdressers and aestheticians had higher test positivity compared with a reference group of individuals without a close-contact occupation. Workers in childcare, education and healthcare showed lower test positivity.

In a cross-sectional study involving 131 flower bulb farmers (mean age = 43 y) and 67 well-matched controls, peripheral and autonomic nerve functions were examined. The study group had been exposed during a period of 20 y (standard deviation = 7) and applied a similar pesticide package. Lifetime cumulative exposure was estimated based on exposure levels for specific application methods and duration of exposure. Exposure-related decreased conduction velocities were found in the motor fibers of the median (-1.1 m/s) and peroneal (fast fibers: -1.2 m/s, slow fibers: -1.3 m/s) nerves, and in the sensory fibers of the median (-1.4 m/s) and sural (-0.9 m/s) nerves. In addition, the refractory period was determined and found to be increased in the sural and peroneal nerves. With regard to the autonomic nerve function, a decrease was found in resting sinus arrhythmia (-10%).

Certain functions of the nervous system were examined in 31 printing workers (mean age 44) exposed to trichloroethene (mean duration 16 years) and 28 controls (mean age 45). In the sural nerve the conduction velocity (SNCV), response amplitude, and refractory period (SRP) were measured. The latencies of the masseter and the blink reflex were determined to test the trigeminal nerve. In the peroneal nerve the conduction velocity of fast and slow nerve fibres, the response amplitude, and the refractory period were determined. As a measure of autonomic nerve function the response of the heart rate was determined to isometric muscle contraction and deep breathing. Individual cumulative exposure was calculated on the basis of exposure levels in the past. The mean cumulative exposure of the exposed workers was 704 ppm x years. For the assessment of the exposure effect relation a multiple linear regression model was used. A slight reduction (-1 1 m/s) in the SNCV was found and a prolongation (04 ms) of the SRP (mean of the controls 1-95 ms). The latency of the masseter reflex (mean 10-4 ms) had increased (0-4 ms). With respect to the blink reflex no prolongation was found. No impairment was found in the functions of motor and autonomic nerves. This study shows that the refractory period may be a sensitive indicator of preclinical toxic neuropathies. Long term exposure to trichloroethene at threshold limit values (about 35 ppm) may slightly affect the trigeminal and sural nerves.Trichloroethene (TRI) has been applied in industry as a solvent and a degreasing agent since the beginning of this century. In medicine it was used as an 87 anaesthetic and analgesic. The neurotoxicity of TRI has been established in both applications.'23 Lesions of the cranial nerves, the trigeminal nerve in particular, were found after very high exposures.Several reports suggest that non-accidental industrial exposure to TRI may also result in some nerve impairment.4 67 These reports do not allow the derivation of exposure effect relations. This hampers the evaluation of the threshold limit value with respect to possible neurotoxic effects. In a review, Spencer and Schaumburg also state that there are no adequate epidemiological studies of worker populations to evaluate the neurotoxicity of TRI.V Several methods have been proposed that may contribute to the early detection of TRI induced nerve dysfunctions. Matikainen and Juntunen9 studied the variation in heart rate in workers with a toxic neuropathy to ascertain the function of the autonomic nerve system. Studies in diabetic and uraemic patients suggest that a prolongation of the refractory period of nerve fibres may precede a decrease in the conventionally measured conduction velocity."'0' In workers exposed to CS, we found slight nerve dysfunction when applying these two methods." It is well known that solvents may also affect central nervous functions, resulting in psychoorganic disturbances. Hogstedt et all" proposed that the so called questionnaire-16 be used for a first crude scr...

Certain functions of the peripheral and autonomic nervous systems, and colour discrimination were examined in 45 workers (mean age 49; mean exposure to carbon disulphide (CS2) 20 years) and 37 controls (mean age 48). Conduction velocity and refractory period of the peroneal and sural nerves were determined. The conduction velocity of the slower fibres of the peroneal nerve was measured by means of an improved method that makes use of the refractory period. Function of autonomic nerves was assessed by measuring the variation in heart rate during rest, during deep breathing, and during isometric muscle contraction. Colour discrimination was evaluated by the Lanthony desaturated test. Individual cumulative exposure to CS2 was calculated on the basis ofexposure in the past and individual job history. Mean cumulative exposure was 165 ppm-years. The peroneal nerves of exposed workers showed a decrease (-10 m/s) in conduction velocity of the slow fibres and a prolongation (0-1 ms) of the refractory period (mean 1-6 ms) compared with controls. These effects were related to cumulative exposure. No impairment of function of the sural nerve or of colour discrimination was found. The muscle heart reflex was decreased in the exposed group, but this was not related to cumulative exposure. This study has established more firmly that a decrease in conduction velocity of slow motor fibres occurs at low levels of exposure to CS2. Prolonged occupational exposure to less than 20 ppm carbon disulphide (CS2) is known to adversely affect peripheral nerves"X and colour discrimination,7 and a decrease in conduction velocity of slow motor fibres is an early indicator of CS2 neuropathy.45Methods have been described that may be used to improve the early detection of neuropathy induced by CS2. Studies on diabetic and uraemic patients suggest that prolongation of the refractory period of peripheral nerves may be an earlier symptom of neural impairment than the decrease in conduction velocity.89 Matikainen and Juntunen'0 found that the variation in heart rate in workers suspected of toxic neuropathy was less than in a control group.The objectives of our investigation were to determine whether a low level exposure to CS2 affected the peripheral nervous system and colour vision, and to study the feasibility of proposed diagnostic methods. SubjectsAll male workers at a viscose rayon plant who had been exposed to CS2 for 10 years or more, and a selection of non-exposed workers from the same plant were personally contacted by local occupational health personnel; 87 workers agreed to participate. After exclusion offive workers with other risk factors for neuropathy the analyses concerned 45 exposed workers and 37 controls. The exposed workers (mainly shift workers) had a mean age of 49 (SD 7) and had been exposed to CS2 for a mean of 20 (SD 9) years. The controls were matched on a group basis with the exposed workers for socioeconomic state, shift work, nationality, and age (48 (SD 7) years); they had all been employed for at least 10...