D.C. Mun. Regs. tit. 22, r. 22-B213
No person who is affected by, or believed by the Director upon probable cause to be affected by, a communicable disease in a communicable form; and no person who is, or is believed by the Director upon probable cause to be, a carrier of a communicable disease; shall actively engage in any occupation in which the person is likely to be dangerous to the lives or health of other persons.
No operating proprietor or manager of any business shall permit any person who is, or is believed by the Director upon probable cause to be, a carrier of a communicable disease, to engage or continue to be engaged in any occupation in which the person is likely to be dangerous to the lives or health of other persons.
Except when specifically authorized otherwise by the Director, no person affected with chickenpox, diphtheria, measles, mumps, meningococcus meningitis, poliomyelitis, smallpox, or whooping cough shall ride or be transported during the communicable period of his or her disease in any of the following common carriers:
D.C. Mun. Regs. tit. 22, r. 22-B213