96.A public health director may conduct an epidemiological investigation in any situation where the public health director believes on reasonable grounds that the health of the population is or could be threatened and, in particular,
(1) where the director receives a report of an unusual clinical manifestation following a vaccination under section 69;
(2) where the director receives a report of an intoxication, infection or disease to which Chapter VIII applies;
(3) where the director receives a notice under Chapter IX to the effect that a person is refusing, omitting or neglecting to be examined or treated or to comply with compulsory prophylactic measures;
(4) where the director receives a report under Chapter X.