The association between thromboembolic events (TE) and COVID-19 infection is not completely understood at the population level in the United States. We examined their association using a large US healthcare database. We analyzed data from the Premier Healthcare Database Special COVID-19 Release and conducted a case-control study. Thestudy population consisted of men and non-pregnant women aged18years with (cases) or without (controls) an inpatient ICD-10-CM diagnosis of TE between 3/1/2020 and 6/30/2021. Using multivariable logistic regression, we assessed the association between TE occurrence and COVID-19 diagnosis, adjusting for demographic factors and comorbidities. Among 227,343 cases, 15.2% had a concurrent or prior COVID-19 diagnosis within 30days of their index TE. Multivariable regression analysis showed a statistically significant association between a COVID-19 diagnosis and TE among cases when compared to controls (adjusted odds ratio [aOR]1.75, 95% CI 1.72-1.78). The association was more substantial if a COVID-19 diagnosis occurred 1-30days prior to index hospitalization (aOR3.00, 95% CI 2.88-3.13) compared to the same encounter as the index hospitalization. Our findings suggest an increased risk of TE among persons within 30days of beingdiagnosed COVID-19, highlighting the need for careful consideration of the thrombotic risk among COVID-19 patients, particularly during the first month following diagnosis.

OBJECTIVE: To analyze acute hazardous substance release surveillance data for events involving secondary contamination of hospital emergency departments (EDs). Secondary contamination of EDs may occur when a patient exposed to a hazardous chemical is not decontaminated before arrival at the ED and when ED staff are not wearing appropriate personal protective equipment. This can result in adverse health outcomes among department personnel, other patients, and visitors. Even events without actual secondary contamination risk can be real in their consequences and require the decontamination of the ED or its occupants, evacuation, or temporary shutdown of the ED. METHODS: Events involving secondary contamination were identified by using the Hazardous Substances Emergency Events Surveillance system and the National Toxic Substance Incidents Program from 2007 to 2013. RESULTS: Five incidents involving the threat of secondary contamination (0.02% of all events reported to the surveillance systems [n=33,001]) were detected and are described. Four incidents involved suspected secondary contamination in which the facility was evacuated or shut down. CONCLUSIONS: These results suggest that although rare, incidents involving secondary contamination continue to present a hazard for emergency departments. Suggested best practices to avoid secondary contamination have been described. Hospitals should be made aware of the risks associated with secondary contamination and the need to proactively train and equip staff to perform decontamination.