A review of outbreaks of waterborne disease associated with ships: evidence for risk management.
OBJECTIVE
The organization of water supply to and on ships differs considerably from that of water supply on land. Risks of contamination can arise from source water at the port or during loading, storage, or distribution on the ship. The purpose of this article is to review documented outbreaks of waterborne diseases associated with passenger, cargo, fishing, and naval ships to identify contributing factors so that similar outbreaks can be prevented in the future.


METHODS
The authors reviewed 21 reported outbreaks of waterborne diseases associated with ships. For each outbreak, data on pathogens/toxins, type of ship, factors contributing to outbreaks, mortality and morbidity, and remedial action are presented.


RESULTS
The findings of this review show that the majority of reported outbreaks were associated with passenger ships and that more than 6,400 people were affected. Waterborne outbreaks due to Enterotoxigenic Escherichia coli, noroviruses, Salmonella spp, Shigella sp, Cryptosporidium sp, and Giardia lamblia occurred on ships. Enterotoxigenic E. coli was the pathogen most frequently associated with outbreaks. One outbreak of chemical water poisoning also occurred on a ship. Risk factors included contaminated port water, inadequate treatment, improper loading techniques, poor design and maintenance of storage tanks, ingress of contamination during repair and maintenance, cross-connections, back siphonage, and insufficient residual disinfectant.


CONCLUSIONS
Waterborne disease outbreaks on ships can be prevented. The factors contributing to outbreaks emphasize the need for hygienic handling of water along the supply chain from source to consumption. A comprehensive approach to water safety on ships is essential. This may be achieved by the adoption of Water Safety Plans that cover design, construction, operation, and routine inspection and maintenance.
Rooney
Roisin M
RM
Water, Sanitation and Health Programme, Department of Protection of the Human Environment, World Health Organization, Geneva, Switzerland. rooneyr@who.int
Bartram
Jamie K
JK
Cramer
Elaine H
EH
Mantha
Stacey
S
Nichols
Gordon
G
Suraj
Rohini
R
Todd
Ewen C D
EC
D003140:Communicable Disease Control / Q000379:methods / Q000592:standards; D004196:Disease Outbreaks / Q000517:prevention & control / Q000706:statistics & numerical data; D019317:Evidence-Based Medicine; D006801:Humans; D009017:Morbidity; D009326:Naval Medicine / Q000379:methods / Q000592:standards; D020380:Needs Assessment; D011159:Population Surveillance; D017410:Practice Guidelines as Topic; D012307:Risk Factors; D012308:Risk Management / Q000379:methods / Q000592:standards; D012767:Ships / Q000706:statistics & numerical data; D014867:Water / Q000469:parasitology; D014871:Water Microbiology / Q000592:standards; D018508:Water Purification / Q000379:methods / Q000592:standards; D014944:World Health Organization
D014867:Water