Atraitatic Disease Carrier
You are infected with a disease but show no symptoms yourself. Choose a disease from official fifth edition sources or another source. You transmit this disease to others via the transmission method associated with it. Anyone who comes into contact with you via its transmission method must succeed on a DC 8 + (IE) Constitution saving throw or become infected.
Real-world Examples
Typhoid Fever, HIV, Epstein–Barr Virus, Clostridioides Difficile, Cholera, Chlamydia, Poliomyelitis, Tuberculosis, COVID-19
Assistive Options
Depending on the method of transmission, taking precautions (e.g., a face mask for air transmission) can give the potential target advantage on the Constitution saving throw.
Magical Assistance
Magic that cures diseases can eliminate this condition, but anytime you need to make a saving throw against disease, unless you succeed by at least 5, you become an Atraitatic Disease Carrier of the new disease.