Fact Sheet N°
Shipping and health
A recently released World Health Organization (WHO)
literature review1 has identified over 100 disease outbreaks
associated with ships since 1970. This is probably an underestimate
because many outbreaks are not reported and some may go undetected. Such
outbreaks are of concern because of their potentially serious health
consequences and high costs to the industry. The main diseases associated
with ships are gastrointestinal disease and Legionnaires' disease.
The passenger shipping industry (cruise ships and
ferries) has expanded considerably in recent decades. In 2000, 10 million
people travelled on cruise ships. This figure is expected to double by the
The cargo shipping industry is also growing. It is
estimated that 1.2 million seafarers are employed on general cargo
vessels. Many spend months at sea, sometimes in remote regions of the
world. Naval vessels also carry considerable numbers of crew, sometimes
over 5,000 per ship.
- A wide range of pathogens affected passengers and crew during
ship-associated gastrointestinal disease outbreaks. These included Vibrio
parahaemolyticus, Salmonella species, Hepatitis A,
enterotoxigenic Escherichia coli, enterohaemorrhagic Escherichia
coli O157, Shigella species, Staphylococcus aureus,
Norwalk-like virus (NLV), Cryptosporidium, Giardia lamblia
- Most of the detected gastrointestinal disease outbreaks were
associated with cruise ships and were linked to food or water consumed
onboard ship. Factors contributing to outbreaks included contaminated
bunkered water, inadequate disinfection of potable water, potable
water contaminated by sewage on ship, poor design and construction of
potable water storage tanks, deficiencies in food handling,
preparation and cooking and use of seawater in the galley.
- NLV is the most common pathogen implicated in outbreaks. Symptoms
often start with sudden onset of vomiting and/or diarrhoea. There may
be fever, abdominal cramps and malaise. The virus can spread in food
or water or from person to person. NLV is a very infectious virus,
and, in one outbreak on a cruise ship in 1998, over 80% of the 841
passengers were affected.
- Outbreaks of acute gastroenteritis are also frequently reported
aboard naval ships. One outbreak of viral gastroenteritis on a naval
vessel in 1997 affected 1,806 (43%) crewmembers. Another outbreak of a
waterborne infection in 1998 affected 200 crew or 22%. These outbreaks
cause substantial morbidity among military personnel during
- Very little information is available on the incidence of infection
among seafarers on general cargo vessels. Many outbreaks and cases of
infection probably go undetected. However, inspections on ships
carried out in the year 2000 revealed that 9.2% had deficiencies
relating to food and catering2.
- Legionnaires' disease is a potentially fatal form of pneumonia, first
recognized in 1976. The disease is normally contracted by inhaling
legionella bacteria deep into the lungs. Legionella species can
be found in tiny droplets of water (aerosols) or in droplet nuclei (the
particles left after the water has evaporated).
- The WHO review showed that over 50 incidents of Legionnaires'
disease, involving over 200 cases, were associated with ships in the
past three decades.
- For example, an outbreak of Legionnaires' disease occurred on a
single cruise ship in 1994: 50 passengers were affected on nine
different cruises and one passenger died. The disease was linked to a
whirlpool spa on the ship.
- The problem is not restricted to passenger ships. Surveys carried
out on general cargo ships have shown drinking water and air
conditioning systems to be contaminated with Legionella pneumophila3.
- Serologic surveys of seafarers on cargo ships have also shown that a
high proportion have antibodies to Legionella pneumophila, suggesting
that those on board ships are at increased risk of legionellosis
compared with communities onshore3.
- Control measures, such as proper disinfection, filtration and
storage of source water, avoidance of dead ends in pipes and regular
cleaning and disinfection of spas are therefore required to reduce the
risk of legionellosis on ships.
International Health Regulations
- The International Health Regulations (IHR), adopted by the World
Health Organization (WHO) in 1969, provide a regulatory framework to
support public health security by preventing the international spread of
infectious diseases through permanent public health measures for
travellers, cargo, and points of entry. These regulations replaced the
1951 International Sanitary Regulations.
- The purpose of the IHR is to provide the maximum protection against
the international spread of diseases with minimum interference with
- The current requirements of the IHR relate to provision of potable
water at ports, public health inspections of ships, proper disposal of
waste from ships, appropriate facilities for examining and isolating
travellers and maintaining vector free zones and vector surveillance.
- The IHR are currently being updated. It is proposed that the revised
IHR cover both urgent and routine public health services at ports,
airports and ground crossings.
WHO Guide to Ship Sanitation
- The WHO Guide to Ship Sanitation4 is the official
global reference on health requirements for ship construction and
operation and is directly referenced in Article 14 of the IHR.
- Its purpose is to standardize the sanitary measures taken in ships,
to safeguard the health of travellers and to prevent the spread of
infection from one country to another. The present edition of the Guide
is based on the results of a survey of 103 countries and represents a
synthesis of best national practice.
Revision of the Guide to Ship Sanitation
- The Guide was first published in 1967 and was reprinted with
minor amendments in 1987. The construction, design and size of ships
have changed dramatically since the 1960s and the greatly increased
level of transport by ships poses new hazards (e.g. Legionnaires'
disease) that were not foreseen when the 1967 Guide was
- Therefore, WHO is now updating the Guide in close
collaboration with the International Labour Organization (ILO) and the
International Maritime Organization (IMO).
- A meeting was held in Miami, United States on 3-4 October 2001 to
discuss and recommend the proposed contents of the revised Guide. Participants
represented the ship building industry, cruise ship operators,
seafarers associations, collaborating member states for the IHR, Port
State Control, Port Health Authorities and other regulatory agencies
attended. Experts from Australia, Brazil, Canada, Egypt, Finland,
India, Morocco, the Netherlands, Norway, Russia, South Africa,
Thailand, the United Kingdom and the United States are involved in the
Recommendations on the revised Guide
The meeting's participants recommended that the revised
- Apply to all ships including passenger ships, general cargo vessels,
fishing vessels, naval vessels and tankers;
- Cover preventive environmental health management including water
supply at port, water production, treatment and distribution on ship,
swimming and spa pools, waste disposal, food safety and vermin and
vector control; and
- Contain concluding chapters on disease surveillance, outbreak
investigation, and routine inspection and audit.
The revised Guide will be based on a critical
review of available evidence, including experience regarding effectiveness
and feasibility of preventative and remedial measures.
The revised Guide is scheduled to be published
1. World Health Organization. Sustainable Development
and Healthy Environments. Sanitation on Ships. Compendium of outbreaks of
foodborne and waterborne disease and Legionnaires' disease associated with
ships, 1970-2000. WHO/SDE/WSH/01.4.
2. Paris Memorandum of Understanding on Port State
Control, Blue Book. 2000.
3. Temeshnikova ND, Brudny PA, Marakusha BI,
Tartaknvskii IS and Prosorovskii SV. The presence of legionella spp
in the water system of ships. In Proceedings of the 11th
meeting of the European Working Group on Legionella Infections. Norway,
4. Lamoureux V B. Guide to Ship Sanitation. WHO.
For further information,
please contact the Office of the Spokesperson, WHO, Geneva; Tel.: (+41 22)
791 2599, Fax: (+41 22) 791 4858, E-mail: firstname.lastname@example.org
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