When a vessel hailing from a contaminated port has been subjected to an operation for the destruction of rats, this operation shall not be repeated unless the vessel has stopped and moored at a wharf in a contaminated port, or unless the presence of dead or diseased rats is discovered on board.
The crew and passengers may be subjected to a surveillance not to exceed five days from the date on which the vessel left the contaminated port. The landing of the crew may also be forbidden during the same time except in connection with the service.
The competent authority of the port of arrival may always demand an affidavit from the ship's physician, or in default of such physician, from the captain, to the effect that there has not been acase of plague on the vessel since its departure and that no unusual mortality among the rats has been observed.
Art. 24. When rats have been recognized as plague-stricken on board an uninfected vessel as a result of a bacteriological examination, or when an unusual mortality has been discovered among these rodents, the following measures shall be applied:
I. Vessels with plague-stricken rats:
a) Medical inspection.
b) The rats shall be destroyed either before or after the discharge of the cargo as rapidly as possible and at all events within a maximum period of forty-eight hours, avoiding injury to the cargo, plating, and engines. On vessels in ballast this operation shall be performed as soon as possible and at all events before taking on cargo.
c) The parts of the vessel and the articles which the health authority considers to be contaminated shall be disinfected.
d) The passengers and crew may be subjected to a surveillance whose duration shall not exceed five days from the date of arrival, save exceptional cases, in which the health authority may prolong the surveillance to a maximum of ten days.
II. Vessels on which an unusual mortality among rats is discovered:
a) Medical inspection.
b) An examination of the rats with regard to the plague shall be made as far and as quickly as possible.
c) If the destruction of the rats is deemed necessary, it shall take place under the conditions indicated above for vessels with plague-stricken rats.
d) Until all suspicion is removed, the passengers and the crew may be subjected to a surveillance whose duration shall not exceed five days from the date of arrival, save exceptional cases, in which the health authority may prolong the surveillance to a maximum of ten days.
Art. 25. The health authority of the port shall deliver to the captain or to the shipowner or his agent, whenever demanded, a certificate to the effect
