COVID-19 in a Correctional Facility Employee Following Multiple Brief Exposures to Persons with COVID-19 - Vermont, July-August 2020.

On August 11, 2020, a confirmed case of coronavirus disease 2019 (COVID-19) in a male correctional facility employee (correctional officer) aged 20 years was reported to the Vermont Department of Health (VDH). On July 28, the correctional officer had multiple brief encounters with six incarcerated or detained persons (IDPs)* while their SARS-CoV-2 test results were pending. The six asymptomatic IDPs arrived from an out-of-state correctional facility on July 28 and were housed in a quarantine unit. In accordance with Vermont Department of Corrections (VDOC) policy for state prisons, nasopharyngeal swabs were collected from the six IDPs on their arrival date and tested for SARS-CoV-2, the virus that causes COVID-19, at the Vermont Department of Health Laboratory, using real-time reverse transcription-polymerase chain reaction (RT-PCR). On July 29, all six IDPs received positive test results. VDH and VDOC conducted a contact tracing investigation† and used video surveillance footage to determine that the correctional officer did not meet VDH's definition of close contact (i.e., being within 6 feet of infectious persons for ≥15 consecutive minutes)§,¶; therefore, he continued to work. At the end of his shift on August 4, he experienced loss of smell and taste, myalgia, runny nose, cough, shortness of breath, headache, loss of appetite, and gastrointestinal symptoms; beginning August 5, he stayed home from work. An August 5 nasopharyngeal specimen tested for SARS-CoV-2 by real-time RT-PCR at a commercial laboratory was reported as positive on August 11; the correctional officer identified two contacts outside of work, neither of whom developed COVID-19. On July 28, seven days preceding his illness onset, the correctional officer had multiple brief exposures to six IDPs who later tested positive for SARS-CoV-2; available data suggests that at least one of the asymptomatic IDPs transmitted SARS-CoV-2 during these brief encounters.

Organic carbon sequestration in sediments of subtropical Florida lakes.

Recent studies have shown that sediments of temperate and tropical lakes are sinks for organic carbon (OC), but little is known about OC burial in subtropical lakes. There are questions regarding the ability of subtropical lakes to store OC, given their relatively warmwater temperatures, lack of ice cover, frequent water-column mixing, and labile carbon forms. We used 210Pb-dated sediment cores from 11 shallow Florida (USA) lakes to estimate OC burial, i.e. net OC storage, over the last ~100 years. Shallow Florida water bodies average ~30% OC content in their sediments and displayed rates of net OC accumulation (63-177 g C m-2 a-1) that are similar to natural temperate lakes, but lower than temperate agricultural impoundments. We considered the influence of lake morphometry on OC storage in our study lakes, but did not observe an inverse relationship between lake size and OC burial rate, as has been seen in some temperate lake districts. We did, however, find an inverse relation between mean water depth and OC sequestration. Despite recent cultural eutrophication and the associated shift from macrophyte to phytoplankton dominance in the Florida study lakes, overall OC burial rate increased relative to historic (pre-1950 AD) values. Lakes cover >9000 km2 of the Florida landscape, suggesting that OC burial in sediments amounts to as much as 1.6 Mt a-1. The high rate of OC burial in Florida lake sediments indicates that subtropical lakes are important for carbon sequestration and should be included in models of global carbon cycling.

Assessment of metal contamination in the biota of four rivers experiencing varying degrees of human impact.

Urbanization, agriculture, and other land transformations can affect water quality, decrease species biodiversity, and increase metal and nutrient concentrations in aquatic systems. Metal pollution, in particular, is a reported consequence of elevated anthropogenic inputs, especially from urbanized areas. The objectives of this study were to quantify metal (Cu, Al, Cd, Ni, and Pb) concentrations in the waters and biota of four streams in South Georgia, USA, and relate metal concentrations to land use and abiotic and biotic stream processes. Additionally, macrophytes, invertebrates, and fish were identified to assess biodiversity at each site. Metal concentrations in the three trophic levels differed among sites and species, correlating to differences in land use surrounding the rivers. The highest metal concentrations (except Al) were found in the streams most impacted by urbanization and development. Al concentrations were highest in streams surrounded by land dominated by forested areas. Metal content in macrophytes reflected metal concentrations in the water and was at least three orders of magnitude higher than any other trophic level. Despite metal concentration differences, all four streams contained similar water quality and were healthy based on macroinvertebrate community structure. This study provides insight into the impact of urbanization and the fate and effects of metals in river ecosystems with varying degrees of anthropogenic impact.

The prevalence and factors associated with QTc prolongation among emergency department patients.

STUDY OBJECTIVE: Previous studies have suggested that QTc prolongation may lead to significant morbidity and mortality. The prevalence of QTc prolongation among emergency department (ED) patients is unknown. The purpose of this study is to determine the prevalence of QTc prolongation among ED patients. METHODS: This was a retrospective review of ED and inpatient data for all patients with an ECG conducted for any reason at a tertiary care university ED during a 3-month period. QTc prolongation was defined as computer-generated QTc intervals greater than or equal to 450 ms for men and greater than or equal to 460 ms for women. RESULTS: Of the 1,558 eligible cases, 544 patients had QTc prolongation (35%; 95% confidence interval [CI] 32% to 37%). The prevalence of QTc intervals greater than or equal to 500 ms was 8% (120/1,558; 95% CI 6% to 9%). The most common comorbidities were structural heart disease, renal failure, and stroke. Forty-four percent (239/544; 95% CI 40% to 48%) of patients with any degree of QTc prolongation were discharged from the ED. Furthermore, 23% (28/120; 95% CI 16% to 32%) of patients with QTc intervals greater than or equal to 500 ms were discharged from the ED, including 16 patients with QTc intervals greater than or equal to 500 ms and QRS durations less than 120 ms (16/60; 27%; 95% CI 16% to 40%). Five percent of the patients with QTc prolongation died in the ED or during hospitalization (27/544; 95% CI 3% to 7%); none had QTc prolongation or torsades de pointes listed as a cause of death. CONCLUSION: QTc prolongation occurred frequently among ED patients who had an ECG study for any reason. Nearly half of all patients with QTc prolongation were discharged from the ED.