- d) Until all suspicion is removed, the passengers and crew may be subjected to a surveillance whose duration shall not exceed five days from the date of arrival.
Art. 26. It is recommended that vessels be periodically rid of their rats, the operation to take place at least once every six months. The health officer of the port in which the rat ridding operation is performed shall deliver to the captain, owner, or agent, whenever request is made therefor, a certificate showing the date of the operation, the port where it was performed, and the method employed.
It is recommended that the health authorities of ports at which vessels stop which practice periodical rat ridding keep account of the aforementioned certificates in determining the measures to be taken, especially as regards the provisions of No. 3 of the 2d paragraph of article 24.
C. Measures concerning cholera
Art. 27. Vessels infected with cholera shall be subjected to the following measures:
1. Medical inspection.
2. The patients shall be immediately landed and isolated.
3. The other persons shall likewise be landed and subjected, from the date of arrival of the vessel, to an observation or a surveillance whose duration shall vary according to the sanitary condition of the vessel and the date of the last case, without, however, exceeding five days; provided this period is not exceeded, the medical authority may proceed to make a bacteriological examination as far as necessary.
4. The soiled linen, wearing apparel, and other articles of the crew and passengers which are considered by the health authority of the port as being contaminated shall be disinfected.
5. The parts of the vessel which have been occupied by cholera patients or which are considered by the health authority as being contaminated shall be disinfected.
6. When the drinking water stored on board is considered suspicious, it shall be turned off, after being disinfected, and replaced if necessary by water of good quality.
The health authority may prohibit turning water ballast off in ports if it has been taken on in a contaminated port, unless it has been previously disinfected.
It may be forbidden to let run or throw human dejections or the residuary waters of the vessel into the waters of the port, unless they are first disinfected.
Art. 28. Vessels suspected of cholera shall be subjected to the measures prescribed under Nos. 1, 4, 5, and 6 of article 27.
The crew and passengers may be subjected to a surveillance not to exceed five days from the arrival of the vessel. It is recommended that the landing
