A method is provided for acquiring and transmitting biometric data (e.g., vital signs) of a user, where the data is analyzed to determine whether the user is suffering from a viral infection, such as COVID-19. The method includes using a pulse oximeter to acquire at least pulse and blood oxygen saturation percentage, which is transmitted wirelessly to a smartphone. To ensure that the data is accurate, an accelerometer within the smartphone is used to measure movement of the smartphone and/or the user. Once accurate data is acquired, it is uploaded to the cloud (or host), where the data is used (alone or together with other vital signs) to determine whether the user is suffering from (or likely to suffer from) a viral infection, such as COVID-19. Depending on the specific requirements, the data, changes thereto, and/or the determination can be used to alert medical staff and take corresponding actions.