Suppose Alice is permanently at home with only one caregiver. The system should never tell Alice that she has been in contact with a virus carrier because that

Suppose Alice is permanently at home with only one caregiver. The system should never tell Alice that she has been in contact with a virus carrier because that will imply that the caregiver tested positive. Instead, the system should rather tell Alice she may have been exposed to the virus and should get tested. Bloom filters can provide that uncertainty.