To the Editor.
—While Dr Koo and colleagues1 should be complimented on their report of diarrheal disease outbreaks on cruise ships, the issues they note extend well beyond the civilian cruise ship industry. United States Navy aircraft carriers are quite different from cruise liners, but diarrheal disease outbreaks occasionally occur that can have military significance. After a visit to a North African port in 1988, a study from the USS John F. Kennedy (CV 67) supported the significance of onshore food-borne sources.2 They detailed the impact on the ship's medical requirements and personnel availability. After a port visit in the Mediterranean in 1991, the medical department of the USS Forrestal (CV 59) treated more than 750 cases of diarrheal disease in a crew of 5000.3 Another ship in the company treated 15% of the crew for diarrheal diseases, though no cause was established for either ship. During