When we told my son, who was trained as a biologist, that we were going on a cruise, he muttered darkly about norovirus. We dismissed his forebodings. But a couple of days out our ship, with more than 2000 passengers aboard, was, indeed, hit by an outbreak.
"Told you," the irritating boy declared later. "Cruise ships are basically massive floating petri dishes with the humans as the growth medium." This may be something of an exaggeration, but epidemics of this nasty form of gastro-enteritis are a persistent problem for cruise companies.
The US Center for Disease Control and Prevention says cruise ships are at no higher risk from norovirus than land-based facilities; the virus is thought to cause 90 per cent of non-bacterial outbreaks of gastro-enteritis worldwide. Closed communities like prisons, hospitals, and camps are vulnerable because of the ease of transmission of the disease and cruise ships are particularly conspicuous examples.
This speed of transmission is the headache for cruise ships rather than the seriousness of the condition which, while unpleasant, is usually short-lived and not life-threatening.
A study of an outbreak at a scout camp suggested each infected person infected another 14.
Bringing such contagion under control is not easy and we were impressed by the operation which our ship, the Radiance of the Seas, mounted. The fact that it had struck was quickly announced and radical counter-measures were put in place.
Hand sanitising was mandatory every time you entered a food area and all self-service provision, of which there was much, was stopped. Every item, down to ice from vending machines and hot water for tea, was dispensed by surgical glove-wearing crew. Every member of the ship's company, from photographers to art auctioneers, was pressed into action and there was a perpetual parade of people disinfecting every conceivable surface, from hand rails to chairs.
The hygiene message was reinforced to the point of tedium by the captain's announcements and in the ship's publications. And what were presumably the higher-risk attractions such as the children's activities and the water slide were closed.
For us, the biggest inconvenience was the closure of the library, which was hardly holiday-wrecking. If we had had children, it might have been different - and it was hard not to feel sympathy for those who conscientiously admitted to suffering and were put into isolation just as we reached ports for excursions.
The outbreak was a bore, but as my father, who worked for a shipping company, used to say: "Worse things happen at sea." It won't stop me cruising.