Disclosed are embodiments for estimating risk associated with a user of a wireless device. In some embodiments, the risk relates to a risk of infection by a contagious disease. For example, in some embodiments, the contagious disease is Coronavirus 2019. In some embodiments, locations of multiple wireless devices are estimated based on signal strengths of signals associated with the devices. Neighboring devices are identified based on highest probability regions of the devices that are determined based on associated signals. A measure of proximity to other devices is then determined based on probabilities that each device is located in neighboring regions. The risk is then based on the measure of proximity. In some embodiments, a risk of a first user associated with a first wireless device is based, in part, on a risk of a second user within a proximity of the first user.