The article reviews the prevalence and impact of asymptomatic SARS-CoV-2 infections, which have been a significant but uncertain factor in the ongoing pandemic. Asymptomatic individuals account for approximately 40% to 45% of all 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 detected by computed tomography. The authors emphasize the importance of expanding testing programs to include asymptomatic individuals and suggest innovative surveillance tactics such as crowdsourcing digital wearable data and monitoring sewage sludge to better understand and control the spread of the virus. The review highlights several cohorts where asymptomatic infections were prevalent, including cruise ship passengers, prison inmates, and residents of nursing facilities, and discusses the challenges in distinguishing asymptomatic from presymptomatic cases. The findings suggest that the high proportion of asymptomatic infections could explain the rapid global spread of the virus and highlight the need for broader testing and preventive measures.The article reviews the prevalence and impact of asymptomatic SARS-CoV-2 infections, which have been a significant but uncertain factor in the ongoing pandemic. Asymptomatic individuals account for approximately 40% to 45% of all 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 detected by computed tomography. The authors emphasize the importance of expanding testing programs to include asymptomatic individuals and suggest innovative surveillance tactics such as crowdsourcing digital wearable data and monitoring sewage sludge to better understand and control the spread of the virus. The review highlights several cohorts where asymptomatic infections were prevalent, including cruise ship passengers, prison inmates, and residents of nursing facilities, and discusses the challenges in distinguishing asymptomatic from presymptomatic cases. The findings suggest that the high proportion of asymptomatic infections could explain the rapid global spread of the virus and highlight the need for broader testing and preventive measures.