Health and Cruise ships
In general, there are few health risks associated with cruise ship holidays. As long as the traveller is up-to-date with routine vaccinations (such as ADT) no further vaccinations may be required. If, however, there is a possibility that meals will be eaten on-shore in any less-developed country, vaccination against hepatitis A would be advisable. Despite the well-publicised outbreak of typhoid fever amongst some cruise-ship passengers who ate at a restaurant in PNG in 1999, the risk of typhoid fever is extremely low & vaccination would not be routinely recommended. The main method of protection against food- & water-borne diseases in less-developed countries should be through following the rules of eating & drinking safely overseas (using bottled water, avoiding shellfish & uncooked foods). This is well covered in an excellent publication "A Health Guide for International Travellers" produced by the Travel Doctor-TMVC Group of centres around Australia.
Respiratory infections can sometimes spread quickly on cruise ships. It is therefore advisable that passengers be vaccinated with the current flu vaccine.
The risk of malaria & other mosquito-borne diseases for passengers on a cruise ship is extremely low. Cruise ships usually moor in port during the day, & depart in the early evening. Mosquito avoidance measures would be sufficient.
Sea-sickness may be a problem for some passengers. There are a number of behavioural measures that can sometimes be adopted to prevent this:
· Minimise exposure through location in the middle of the vessel where there is least movement, & adopt a horizontal or semi-recumbent position;
· Minimise head & body movements;
· Restrict visual activity by fixing vision on the horizon or some other external stable object; avoid fixation on a moving object; avoid reading; & close the eyes;
· Ensure good ventilation;
· Engage in distracting behaviour;
· Avoid large meals, but have frequent small amounts of food.
There are also a number of pharmacological agents which can be useful in preventing sea-sickness. Anti-histamines have been shown to be effective, but the non-sedating varieties will not work as they do not cross the blood-brain barrier. Promethazine theoclate (Avomine) or promethazine hydrochloride (Phenergan) as a single daily dose of 25 mg for adults, would be a good option. This can be taken the night before commencing the cruise & perhaps continuing for two or three nights whilst adaptation occurs. An alternative would be dimenhydrinate (Dramamine) 50 mg two to three times daily. Oral hyoscine (Kwells) is recommended for short-term use only & so would not usually be appropriate for a cruise. They give about 4 hours protection, & should not be used for longer than 12 hours, as side-effects can become particularly troublesome with repeated administration.
All cruise-ship passengers should have travel insurance in case a significant medical event occurs during the cruise, which may require intensive treatment & possibly a medical evacuation.