Seafarer mortality and morbidity have been extensively studied, especially in British and Danish seafarers, and for many years diseases of the digestive system have been shown to be a major cause of morbidity and death . Most studies on mortality and morbidity are based on statistics from government agencies and insurance companies, reports from Tele-Medical Advice Services (TMAS), and studies on passenger vessels by cruise doctors. The US Centers for Disease Control and Prevention (CDC) have published many series on outbreaks of acute gastroenteritis on passenger ships.
In mortality studies [1-4], liver cirrhosis, peptic ulcers and pancreatitis dominate in seafarers, and there is a high overall relative risk of all cancers associated with tobacco smoking and alcohol [5-7].
Morbidity studies show that diseases of the digestive system are second only to accidents - and gastritis and ulcers occur as the most frequent GI disorders [8,9]. Thus, the excess gastrointestinal morbidity in seafarers may be related to their work and lifestyle and may to some degree be caused by stress and/or stress-relieving measures [9,10].
It is noteworthy that in Britain a significant reduction in mortality from gastrointestinal diseases and alcoholism has been demonstrated since the 1970s, which is in contrast to the general British population. Shorter contracts, improved work conditions aboard, stricter policies regarding alcohol use at sea, and a shift from European to Asian seafarers are some factors that may influence future series. There are also important limitations to longitudinal mortality studies in seafarers .
Tele-Medical Advice Services (TMAS) report that abdominal complaints (e.g. pain, nausea, vomiting and/or diarrhea) account for 10 - 25% of the maritime radio-medical contacts [11-17]:
Studies from cruise ships [18-21] – with doctor(s) aboard – show that the most frequent GI cause of
- sick leave aboard is acute gastroenteritis,
- hospitalization ashore is ’abdominal pain’ and appendicitis,
- medical sign-off and repatriation is inguinal hernia, and
- referral to a specialist ashore is dental disorders.
Further epidemiology details can be found in the studies referred to below, a selection based on the author’s maritime-medical library and PubMed searches. The quality of the studies varies widely, from small reports comprising a few cases to large statistical series based on official records from insurance companies and government agencies.