Association between SARS-CoV-2 exposure and antibody status among healthcare workers in two London hospitals: a cross-sectional study.

BACKGROUND: Patient-facing (frontline) health-care workers (HCWs) are at high risk of repeated exposure to SARS-CoV-2. AIM: We sought to determine the association between levels of frontline exposure and likelihood of SARS-CoV-2 seropositivity amongst HCW. METHODS: A cross-sectional study was undertaken using purposefully collected data from HCWs at two hospitals in London, United Kingdom (UK) over eight weeks in May-June 2020. Information on sociodemographic, clinical and occupational characteristics was collected using an anonymised questionnaire. Serology was performed using split SARS-CoV-2 IgM/IgG lateral flow immunoassays. Exposure risk was categorised into five pre-defined ordered grades. Multivariable logistic regression was used to examine the association between being frontline and SARS-CoV-2 seropositivity after controlling for other risks of infection. FINDINGS: 615 HCWs participated in the study. 250/615 (40.7%) were SARS-CoV-2 IgM and/or IgG positive. After controlling for other exposures, there was non-significant evidence of a modest association between being a frontline HCW (any level) and SARS-CoV-2 seropositivity compared to non-frontline status (OR 1.39, 95% CI 0.84-2.30, P=0.200). There was 15% increase in the odds of SARS-CoV-2 seropositivity for each step along the frontline exposure gradient (OR 1.15, 95% CI 1.00-1.32, P=0.043). CONCLUSION: We found a high SARS-CoV-2 IgM/IgG seropositivity with modest evidence for a dose-response association between increasing levels of frontline exposure risk and seropositivity. Even in well-resourced hospital settings, appropriate use of personal protective equipment, in addition to other transmission-based precautions for inpatient care of SARS-CoV-2 patients could reduce the risk of hospital-acquired SARS-CoV-2 infection among frontline HCW.

Where, when, and how many tuberculosis patients are lost from presumption until treatment initiation? A step by step assessment in a rural district in Zimbabwe.

OBJECTIVES: To describe the pre-diagnosis and pre-treatment loss to follow-up (LTFU) in the tuberculosis (TB) care cascade in Guruve (2015-16), a rural district in Zimbabwe. DESIGN: Guruve has 19 rural health centres (RHCs) and one district hospital. In this cohort study, persons ≥15 years of age with presumptive pulmonary TB were tracked from the facility presumptive TB registers to the laboratory registers; if laboratory diagnosed, they were tracked to the district TB register (contains details of all TB patients registered for treatment). Each patient was tracked for 90days after registration as presumptive TB and for 90days after laboratory diagnosis. Environmental health technicians transported sputum specimens from the health facilities to the laboratories (n=3). RESULTS: Of 2974 persons with presumptive TB, pre-diagnosis LTFU occurred in 575 (19%, 95% confidence interval 18-21%). Associated factors included registration at a RHC, at a facility more than 2km from the laboratory, and absence of an environmental health technician. Of 162 laboratory diagnosed pulmonary TB patients, pre-treatment LTFU occurred in 19 (12%, 95% confidence interval 8-18%). CONCLUSIONS: The presumptive TB register was helpful to assess the pre-diagnosis gaps beginning from presumption. Pre-diagnosis LTFU can be reduced by placement of an environmental health technician at all facilities.