The Effectiveness of the Third Dose of COVID-19 Vaccine: When Should It Be Performed?

BACKGROUND: COVID-19 vaccination is the most significant step toward the long-term mitigation of SARS-CoV-2-related complication, avoiding disease and death and decreasing virus spread. This study aimed to evaluate, in a real-world setting, booster dose effectiveness to reduce COVID-19 risk considering the amount of time after the end of the two-dose vaccination cycle. A sub-analysis was conducted to adjust the booster dose effect for occupational and demographic factors. METHODS: About 16,000 COVID-19-vaccinated HCWs of three University Hospital Networks in Milan (HN1/HN2/HN3) were included in the study. Data were collected by Occupational Health Physicians of the HNs within specific computerized databases. RESULTS: In univariable analysis, booster dose administration displayed a slightly higher risk of infection with respect to not receiving it, OR = 1.18, with 95% confidence interval (C.I) [0.99, 1.41]. When the model was adjusted with the modulating effect of time from the completion of the vaccination cycle on booster dose administration, the latter resulted in strong protective effect against infection, OR = 0.43, 95% CI [0.26, 0.74]. However, considering the modifying influence of time from the vaccination cycle's completion, the administration of booster doses appeared to have a protective effect against infection. In HN1, students and resident physicians displayed lower odds of infection with respect to physicians. Lastly, a non-linear effect of age was reported. CONCLUSIONS: Our findings suggest that the correct timing in vaccine scheduling and administration is critical to vaccine effectiveness. These findings, applicable to all vaccinations, should help in setting up more effective vaccination strategies.

Neurobehavioral Effects of Low-Dose Chronic Exposure to Insecticides: A Review.

The modes of action of insecticides frequently involve a neurotoxic effect; therefore, the study of neurotoxic effects caused by long-term and low-dose insecticide exposure is of particular interest. This study looks at whether or not new studies conducted after 2009 and up to 2021 have provided new evidence for a better understanding of the actual neurobehavioral risk associated with long-term insecticide exposure. We selected and reviewed studies carried out on the neurobehavioral effects of neurotoxic insecticides (organophosphates and/or carbamates, pyrethroids, multiple or undefined insecticides, and organochlorines) considering occupational and non-occupational exposures. The articles were also scored and ranked based on seven parameters. Eighty-six studies were chosen for a final review process from among the 950 scientific papers identified. Twenty-six addressed occupational exposure and six environmental exposure. Among the latter group of studies, 17 focused on rural residents, to be assumed exposed because of living in rural areas, and 43 on the general population. Pending doubts have not been resolved in the last ten years due to the presence of contradictory and hardly comparable results and the fact that in most of the studies showing an evident neurobehavioral impairment the frequent presence of a previous episode of poisoning and hospitalization, with severe brain hypoxia, impaired the possibility of confirming the presence of a causal association with insecticide exposure. Interestingly, the most severely exposed groups, such as applicators who did not wear personal protective equipment, performed worse on neurobehavioral tests. As for residential exposure, there is sufficient evidence to suggest that prenatal OP exposure may increase the risk of ADHD in children.

Assessing the Impact of Work Activities on the Physiological Load in a Sample of Loggers in Sicily (Italy).

Occupational logging activities expose workers to a wide range of risk factors, such as lifting heavy loads, prolonged, awkward positioning of the lower back, repetitive movements, and insufficient work pauses. Body posture has an important impact on the level of physiological load. The present study involved a group of 40 loggers in the province of Enna (Sicily, Italy) with the aim of defining the impact of logging activities on the workers' physiological strain during the three primary work tasks of felling, delimbing, and bucking. The Zephyr Bioharness measurement system was used to record trunk posture and heart rate data during work tasks. The NASA TLX questionnaire was used to explore workers' effort perception of the work tasks. Based on our results, the most demanding work task was tree felling, which requires a higher level of cardiac cost and longer periods spent in awkward trunk postures. The perceived physiological workload was consistently underestimated, especially by the more experienced loggers. Lastly, as the weight of the chainsaw increased, the cardiac load increased.

Occupational hand and wrist disorders among forestry workers: An exposed-control study to investigate preventive strategies.

BACKGROUND: In the arboriculture sector, some activities are still manually performed by forestry workers, which result consequently exposed to a high risk of developing muscle skeletal disorders. The Italian Compensation Authority reported an increase of work-related tendinopathies and carpal tunnel syndrome in loggers, but screening protocols are not available yet. OBJECTIVES: The objectives were: a) to evaluate the prevalence of tendinopathies and carpal tunnel syndrome in a sample of loggers and b) identify a sound screening approach. METHODS: 41 loggers and 41 paired control workers were recruited for a total of 164 hands. The protocol included 1) demographic data; 2) medical history; 3) identification of CTS symptoms through a questionnaire and a hand-chart; 4) upper limbs clinical examination; 5) Raynaud's diseases questionnaire; 6) wrists ultrasound; 7) NCS of the distal median nerve. RESULTS: The prevalence of tendinopathies was statistically significant only in the non-dominant hand (75, 5% in the exposed group and 53, 6% in the non-exposed group). The prevalence of CTS was 32, 2% in the exposed group and 15, 5% in the non-exposed group. The questionnaire had a sensitivity of 56, 7% and a specificity of 75%. The hand-chart had a sensitivity of 30% and a specificity of 92%. The clinical examination had sensitivity of 30% and specificity of 80%. The ultrasound had a sensitivity of 70% and a specificity of 56%. CONCLUSIONS: Loggers are a population at risk of occupational hand and wrist disorders. The hand-chart could be considered, together with the questionnaire, as the best secondary prevention tool to diagnose CTS.

Hand-Wrist Disorders in Chainsaw Operators: A Follow-Up Study in a Group of Italian Loggers.

Despite the mechanization process implemented in arboriculture, logging tasks are still manually performed by chainsaw operators, which therefore are exposed to the risk of developing hand-wrist musculoskeletal disorders. Our research aimed to: (a) define whether the slight changes observed in 2017 showed an evolution to overt diseases; (b) study some risk determinants for these diseases such as age, working experience, and performing a secondary job. We recruited in a two-year follow-up study, 38 male forestry workers performing logging tasks employed in the Sicilian Forestry Department located in Enna. All the subjects underwent: (1) personal data collection; (2) administration of questionnaire addressed at upper limbs symptoms with a hand chart; (3) physical examination of the upper limbs, including Tinel's and Phalen's maneuvers; (4) ultrasound investigation of the hand-wrist area. In the two-year follow-up study we registered an overall increasing in wrist disorders, thus we can assume that forestry workers may be a target population for wrist diseases and deserve a particular attention in workers' health surveillance programs. Interestingly, the prevalence of wrist-hand disorders resulted to be higher in younger workers.