the crew and passengers, but only in exceptional cases when the health authority has special reason to believe that they are contaminated.
3. Although the measure should not be laid down as a general rule, the health authority may subject vessels coming from a contaminated port to an operation designed to destroy the rats on board, either before or after the discharge of the cargo. This operation should take place as soon and as quickly as possible and should not in any event last more than twenty-four hours, avoiding hindrance to the movement of the passengers and crew between the vessel and the shore and, as far as possible, injury to the cargo, plating, and engines. As for vessels in ballast, that operation will, if there be occasion, be performed as soon and as quickly as possible, and at all events before taking on cargo.
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 a case of plague on the vessel since its departure and that no unusual mortality among the rats has been observed.
Art. 25. 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, avoiding injury, as far as possible, to the cargo, plating, and engines. This operation should take place as soon as possible, in no case lasting more than forty-eight hours. On vessels in ballast this operation shall be performed as soon and as quickly 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.
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.
