Background: Readmission within 30-day in coronavirus disease 2019 (COVID-19) is an important indicator of patient safety and quality of care. Conflicting evidence exists regarding in-hospital mortality in solid organ transplant (SOT) recipients with COVID-19. Furthermore, during the pandemic, an increase in hospital-acquired infections (HAI) potentially partially due to environmental contamination was observed. Objective: This thesis evaluated i) the impact of comorbidities on the odds of 30-day readmission following COVID-19 hospitalization, ii) the risk of in-hospital mortality among SOT recipients with COVID-19, and iii) the efficacy of a novel continuously active disinfectant (CAD) to reduce bioburden and infectious pathogens on environmental surfaces in a critical-care setting. Methods: A retrospective cohort study was conducted using the Premier database of COVID-19 in-patients in the United States. The association between comorbidities and readmission, and the relationship between SOT and in-hospital mortality were examined using logistic regression and log-binomial models respectively. General linear models and logistic regression were used to evaluate the efficacy of the CAD in a randomized controlled trial. Results: Among 331,136 COVID-19 patients, 36,827 (11.1%) were readmitted within 30 days. Each additional comorbidity category was associated with increased odds of all-cause readmission (adjusted odds ratio [aOR], 1.18; 95% confidence interval (CI):1.17–1.19) and readmission for COVID-19 (aOR, 1.10; 95% CI:1.09–1.11). Among 378,111 COVID-19 patients, 3,527 (0.9%) SOT recipients had an increased risk of in-hospital mortality (adjusted relative risk, 1.26; 95% CI, 1.17–1.35). The mean difference in environmental bioburden between the new CAD and the standard disinfectant was -0.59 (95% CI: -1.45 , 0.27) and the odds of detection of epidemiologically important pathogens was 14% lower in rooms cleaned with the CAD compared to the standard disinfectant (OR 0.86, 95% CI: 0.31 -2.32). Conclusions: In COVID-19 patients, readmission was common within 30-days. SOT recipients with COVID-19 are at an increased risk of mortality. Larger trials may be warranted to further evaluate CAD to limit the transmission of infectious pathogens. A better understanding of these risk factors will facilitate hospital epidemiologists to better manage emerging infectious diseases by improving bed-flow planning, resource allocation, and implementing appropriate measures to deliver high-quality patient care.