A narrative review by Daniel P. Oran and Eric J. Topol discusses the prevalence of asymptomatic SARS-CoV-2 infections. The authors found that asymptomatic individuals account for approximately 40% to 45% of SARS-CoV-2 infections and can transmit the virus for an extended period, possibly longer than 14 days. Asymptomatic infections may be associated with subclinical lung abnormalities, and testing programs should include those without symptoms. Innovative tactics for public health surveillance, such as crowdsourcing digital wearable data and monitoring sewage sludge, might be helpful. The review analyzed data from various studies, including those from Iceland, Italy, the Diamond Princess cruise ship, Boston and Los Angeles homeless shelters, New York City obstetric patients, the U.S.S. Theodore Roosevelt, the Charles de Gaulle aircraft carrier, and repatriated citizens from Wuhan, China and Spain, Turkey, and the United Kingdom. These studies suggest that a significant proportion of SARS-CoV-2 infections are asymptomatic, with rates ranging from 30% to 96%. However, the data are limited and not always representative of the general population. The review highlights the difficulty in distinguishing asymptomatic from presymptomatic individuals and the importance of longitudinal testing. It also notes that asymptomatic individuals can transmit the virus to others, which may explain the rapid spread of the virus globally. The findings suggest that testing programs should include those without symptoms, and that public health measures should be modified to address the challenge of asymptomatic transmission. The review concludes that further research is needed to better understand the natural history of SARS-CoV-2 infection and to develop effective strategies for controlling the pandemic. The authors emphasize the need for large, representative studies and longitudinal data to accurately assess the role of asymptomatic infections in the spread of the virus. They also suggest that innovative surveillance tactics, such as using digital wearable data and monitoring sewage sludge, could provide valuable insights for public health officials.A narrative review by Daniel P. Oran and Eric J. Topol discusses the prevalence of asymptomatic SARS-CoV-2 infections. The authors found that asymptomatic individuals account for approximately 40% to 45% of SARS-CoV-2 infections and can transmit the virus for an extended period, possibly longer than 14 days. Asymptomatic infections may be associated with subclinical lung abnormalities, and testing programs should include those without symptoms. Innovative tactics for public health surveillance, such as crowdsourcing digital wearable data and monitoring sewage sludge, might be helpful. The review analyzed data from various studies, including those from Iceland, Italy, the Diamond Princess cruise ship, Boston and Los Angeles homeless shelters, New York City obstetric patients, the U.S.S. Theodore Roosevelt, the Charles de Gaulle aircraft carrier, and repatriated citizens from Wuhan, China and Spain, Turkey, and the United Kingdom. These studies suggest that a significant proportion of SARS-CoV-2 infections are asymptomatic, with rates ranging from 30% to 96%. However, the data are limited and not always representative of the general population. The review highlights the difficulty in distinguishing asymptomatic from presymptomatic individuals and the importance of longitudinal testing. It also notes that asymptomatic individuals can transmit the virus to others, which may explain the rapid spread of the virus globally. The findings suggest that testing programs should include those without symptoms, and that public health measures should be modified to address the challenge of asymptomatic transmission. The review concludes that further research is needed to better understand the natural history of SARS-CoV-2 infection and to develop effective strategies for controlling the pandemic. The authors emphasize the need for large, representative studies and longitudinal data to accurately assess the role of asymptomatic infections in the spread of the virus. They also suggest that innovative surveillance tactics, such as using digital wearable data and monitoring sewage sludge, could provide valuable insights for public health officials.