Development and Assessment of Rapid Testing for SARS-CoV-2 Outbreak (DARTS)

On 12 January 2020, a novel coronavirus was identified as the cause of an outbreak of unexplained pneumonia in Wuhan City, Hubei Province, China. This coronavirus was later named SARS-CoV-2, and the disease it causes COVID-19.

SARS-CoV-2 is a non-segmented, positive sense RNA virus and part of the family of coronaviruses. Similar to the Systemic Acute Respiratory Syndrome (SARS) virus, it binds to the angiotensin-converting enzyme 2 (ACE2) receptor located on type II alveolar cells and intestinal epithelia. SARS-CoV-2 can result in a severe Acute Respiratory Distress Syndrome (ARDS) which is characterised by diffuse alveolar damage and direct viral cytopathic effect on pneumocytes. Some patients who develop COVID19 may respond with a fulminant "cytokine storm" reaction.

As of 23 March 2020, a total of 374,921 COVID-19 cases have been reported in 168 countries with a total of over 16,411 deaths (case fatality amongst confirmed cases of 4.4%) (John Hopkins's Coronavirus Resource centre). Over 293,425 cases and 13,258 deaths have been reported from countries outside mainland China. The World Health Organisation (WHO) declared on the 12th of March the SARS-CoV-2 outbreak a pandemic in the context of a Public Health Emergency of International Concern (PHEIC) [4]. Europe has rapidly become the epicentre of the pandemic and in the UK, cases are increasing daily. There have been 6,724 confirmed cases in the UK as of 23 March 2020, including 190 confirmed inpatients at St George's Hospital NHS Trust (23 March 2020 , Dr. Breathnach, personal communication).

Because of the lack of a validated serological test, the actual number, and therefore the proportion, of people that develop asymptomatic infection remains unknown. This means that an accurate case fatality estimate remains elusive. Due to the rise in the number of diagnostic samples, tests are taking longer than expected. Among the foremost priorities to facilitate public health interventions is a reliable laboratory diagnosis. Prompt case ascertainment is necessary to ensure rapid and effective contact tracing, implementation of infection prevention and control measures according to WHO recommendations, and collection of relevant epidemiological and clinical information.

Because of the lack of a validated serological test, the actual number, and therefore the proportion, of people that develop asymptomatic infections remains unknown. This means that an accurate case fatality estimate remains elusive. Due to the rise of the number of samples to diagnose, tests are taking longer than expected. Among the foremost priorities to facilitate public health interventions is a reliable laboratory diagnosis. Prompt case confirmation is necessary to ensure rapid and effective contact tracing, implementation of infection prevention and control measures according to WHO recommendations, and collection of relevant epidemiological and clinical information.