Hydroxychloroquine to Prevent COVID-19 Disease Amongst Healthcare Workers

Inclusion Criteria: * 18 years of age or older to participate. * Healthcare workers with primary practice in intensive care unit, general internal medicine, * COVID-19 testing centres, emergency rooms, and nursing homes. * COVID\_19 symptom free at the time of randomization and have a negative diagnostic swab. Exclusion Criteria: * Known COVID-19 positivity defined as: a laboratory confirmed case as defined by the local public health institutes * Suspected COVID-19 positivity defined as possessing symptoms consistent with COVID-19 infections such as: headache, fever, nausea, vomiting, diarrhea, dyspnea, dry cough * Healthcare workers with pre-existing retinopathy or serious visual problems * Healthcare workers with known malignancies receiving active chemotherapy or immune modifying medications * Healthcare workers with known autoimmune disorders * Healthcare workers with known QT prolongation * History of ventricular arrhythmias * Participants at risk of malignant arrythmias ○ At risk defined as: A sudden loss of consciousness with injury; anyone in their immediate family, under the age of 45year, with sudden cardiac death; anyone family history of long QT syndrome * Known sensitivity/allergy to hydroxychloroquine * Healthcare workers that are currently pregnant * Healthcare workers that are already taking chloroquine or hydroxychloroquine * Healthcare workers on colchicine or any other anti-viral medication * Healthcare workers taking a medication that may interact with hydroxychloroquine (see table below * Inability to take oral medications * Inability to provide written consent * Known G6PD deficiency