SARS-CoV-2 exposures among healthcare workers in New York City.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a significant impact on hospitals, including the occupational health departments in charge of handling healthcare worker (HCW) staffing during high rates of exposure and infection of HCWs. HCWs who were exposed to a patient or community member infected with SARS-CoV-2 were required to isolate from work for a minimum of 14 days from the date of exposure. AIMS: This study was aimed to assess the relative risk of SARS-CoV-2 infection following different types of workplace and community exposures. METHODS: We analyzed the details of workplace and community exposures of HCWs to SARS-CoV-2 at Montefiore Medical Center in New York between 22 June 2020 and 22 November 2020. RESULTS: Of 562 HCW SARS-CoV-2 exposures analyzed, 218 were from the community and 345 were from the workplace. Twenty-nine per cent of community exposures resulted in infection, which was significantly greater than workplace exposure infection (2%). Household community exposures resulted in a larger frequency of infection than non-household community exposures. Of the seven infections after workplace exposures, five had qualifying exposures to a co-worker and two were exposed to an infected patient during a non-aerosolized procedure. CONCLUSIONS: HCW exposure to SARS-CoV-2 continues to present staffing challenges to healthcare systems. Even with deviations from standard personal protective equipment protocol, workplace exposures resulted in low frequencies of infection. In our study, the primary source of HCW infection was exposure in the community. Our findings support investing in efforts to educate around continued masking and social distancing in the community in addition to interventions targeted at addressing vaccine hesitancy.

Optimization of the production of hCG beta-like material by CaSki human cervical carcinoma cells in roller bottle culture.

This study was aimed at optimizing large-scale roller bottle culture conditions for CaSki human cervical carcinoma cells, to produce ectopic hCG beta-like material in quantities sufficient for subsequent characterization studies. Several cell culture techniques contributed to the achievement of this goal: (1) use of serum-free culture medium; (2) use of intermittent recovery periods in presence of serum; and (3) ultrafiltration of the serum-free medium pool for initial concentration of 100-fold.

Discordant human chorionic gonadotropin results: causes and solutions.

This study was performed to demonstrate the phenomenon of discordant human chorionic gonadotropin (hCG) results, in which some serum specimens are positive in one hCG detection procedure but negative in another procedure. Nine different quantitative hCG procedures were used to document discordant hCG results in 22 cases. A two-site monoclonal antibody immunoradiometric assay had the least tendency to give aberrant low-positive hCG values in nonpregnant patients without neoplasms. Potential causes of discordant hCG results are discussed, and guidelines for dealing with them are suggested. Recommended approaches include analysis in an alternate hCG detection procedure that uses a different technology for collection of antigen-antibody complex, dilution analysis, and sequential hCG analysis.

Stability of human chorionic gonadotropin and its alpha subunit in human blood.

The stability of human chorionic gonadotropin (hCG) and its alpha-subunit in whole blood, plasma, and serum under a variety of sample handling conditions commonly encountered in clinics, hospital wards, physician's offices, and clinical service laboratories was investigated with the use of radioreceptor assay, radioimmunoassays, as well as hormone integrity determinations. The results clearly demonstrate that hCG and its alpha-subunit are stable in unfrozen whole blood, plasma, and serum for at least 6 days and in frozen plasma and serum samples for at least 6 months. Repeated freezing and thawing of the samples during this period had no effect. Separation of plasma or serum from erythrocytes is not needed for at least 12 hours. Hemolysis in samples resulted in a 20% to 30% decrease in hCG and its alpha-subunit levels, which may be attributable to sample dilution.

Human chorionic gonadotropin in BeWo trophoblastic cells after 12 years in continuous culture: retention of intact human chorionic gonadotropin secretion in mechanically versus enzyme-dispersed cells.

Gel filtration and radioimmunological studies were used to demonstrate that BeWo malignant trophoblastic cells, subcultured for more than 12 yr as roller tube colonies using dissection by scalpel, retained the ability to secrete large quantities of intact hCG. By contrast, BeWo cells that had been subcultured weekly for 12 hr using proteolytic enzyme dispersion lost their ability to secrete intact hCG. Rather, a large form of hCG-alpha was the major secretory product, along with lesser amounts of heterogeneous low molecular weight forms of hCG-beta. The gradual loss of hormone secretory ability and fidelity of hormone product by cells in continuous culture is a well known phenomenon. Our results suggest that the habitual use of trypsin-EDTA to subculture cells may accelerate this process.