COVID-19 mortality among Massachusetts workers and the association with telework ability, 2020

BACKGROUND

Working outside the home put some workers at risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exposure and might partly explain elevated coronavirus disease 2019 (COVID-19) mortality rates in the first months of the pandemic in certain groups of Massachusetts workers. To further investigate this premise, we examined COVID-19 mortality among Massachusetts workers, with a specific focus on telework ability based on occupation.

METHODS

COVID-19-associated deaths between January 1 and December 31, 2020 among Massachusetts residents aged 18-64 years were analyzed. Deaths were categorized into occupation-based quadrants (Q) of telework ability. Age-adjusted rates were calculated by key demographics, industry, occupation, and telework quadrant using American Community Survey workforce estimates as denominators. Rate ratios (RRs) and 95% confidence intervals comparing rates for quadrants with workers unlikely able to telework (Q2, Q3, Q4) to that among those likely able to telework (Q1) were calculated.

RESULTS

The overall age-adjusted COVID-19-associated mortality rate was 26.4 deaths per 100,000 workers. Workers who were male, Black non-Hispanic, Hispanic, born outside the US, and with lower than a high school education level experienced the highest rates among their respective demographic groups. The rate varied by industry, occupation and telework quadrant. RRs comparing Q2, Q3, and Q4 to Q1 were 0.99 (95% confidence interval [CI]: 0.8-1.2), 3.2 (95% CI: 2.6-3.8) and 2.5 (95% CI: 2.0-3.0), respectively.

CONCLUSION

Findings suggest a positive association between working on-site and COVID-19-associated mortality. Work-related factors likely contributed to COVID-19 among Massachusetts workers and should be considered in future studies of COVID-19 and similar diseases.

Impact of differential injury reporting on the estimation of the total number of work-related amputations

BACKGROUND

A capture-recapture analysis was performed to estimate the total number of work-related amputations. We examined the impact of misclassification due to differential injury reporting on the estimate of total number of work-related amputations.

METHODS

Bureau of Labor Statistics' Survey of Occupational Injuries and Illnesses (SOII) samples and workers' compensation records (WC) were used to estimate the total number of work-related amputations. Some of the amputation cases in one data source matched with injuries other than amputations in the other data source. We performed sensitivity analyses reassigning such cases as matched amputations.

RESULTS

Depending on how we treated the cases matched with other injuries, the total number of work-related amputations ranged from 276 to 442 cases, yielding dramatically different capture rates (35-87%).

CONCLUSION

Due to differential classification, estimates of work-related amputations would be biased. Our findings highlight the importance of accurately reporting and classifying work-related injuries and illnesses.

Host cellular immune response to pneumococcal lung infection in mice

Although there is substantial evidence that pneumolysin is an important virulence factor in pneumococcal pneumonia, relatively little is known about how it influences cellular infiltration into the lungs. We investigated how the inability of mutant pneumococci to produce pneumolysin altered the pattern of inflammation and cellular infiltration into the lungs. The effect on bacterial growth in the lungs also was assessed. There were three phases of growth of wild-type bacteria in the lungs: a decline followed by a rapid increase and then stasis or decline. The absence of pneumolysin was associated with a more rapid early decline and then a much slower increase in numbers. The pattern of inflammatory-cell accumulation also had distinct stages, and the timing of these stages was influenced by the presence of pneumolysin. Neutrophils began to accumulate about 12 to 16 h after infection with wild-type pneumococci. This accumulation occurred after the early decline in pneumococcal numbers but coincided with the period of rapid growth. Following infection with pneumococci unable to make pneumolysin, neutrophil influx was slower and less intense. Coincident with the third stage of pneumococcal growth was an accumulation of T and B lymphocytes at the sites of inflammation, but the accumulation was not associated with an increase in the total number of lymphocytes in the lungs. Lymphocyte accumulation in the absence of pneumolysin occurred but was delayed.

Staphylococcus aureus stimulates neutrophil recruitment by stimulating interleukin-8 production in dog trachea

The present study examined whether neutrophil recruitment in dog airways by Staphylococcus aureus is mediated by interleukin-8 (IL-8). S. aureus culture supernatant was superfused into an isolated tracheal segment in six dogs, and neutrophil recruitment and IL-8 concentrations were measured in the superfusate. Dog IL-8 was cloned, expressed in Escherichia coli, purified by chromatography, and shown to be biologically active. With the use of an enzyme-linked immunoabsorbent assay (ELISA) for the measurement of dog IL-8, we showed that S. aureus supernatant induced neutrophil recruitment and increased IL-8 concentration in the superfusate in a time-dependent manner. The chemotactic activity present in the superfusate 6 h after superfusion with S. aureus was inhibited by an anti-IL-8 antibody. S. aureus supernatant also stimulated IL-8 production and gene expression by cultured canine tracheal epithelial cells. These results provide evidence that IL-8 plays a major role in S. aureus-induced neutrophil recruitment in the airways by stimulating IL-8 production in airway cells.