A major outbreak of typhoid among asylum seekers living on a ship in the Netherlands has been traced to raw sewage which was allowed to mix with tanks of freshwater for drinking and cooking.
A total of 72 cases of the highly contagious disease were confirmed during the spring 2022 outbreak on the Liberty Ann, an old cruise ship which was being used as emergency accommodation in Haarlem.
Details of the outbreak were released this weekend, prior to the opening in Copenhagen on 15 April of this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID), which will hear a full report of investigations into the outbreak that led to 25 people being hospitalised.
One of those leading the investigation, Dr Anne de Vries, of the municipal health service Kennemerland in Haarlem, the Netherlands, said they had discovered that fresh water and wastewater tanks on the ship shared a common wall which was severely corroded and peppered with small holes.
“This allowed sewage containing Salmonella typhi, the bacterium which causes typhoid fever, to leak into the tank containing fresh water, which was then used to drink and prepare food,” she said.
If typhoid is treated promptly with antibiotics, infection is usually mild. However, without treatment, it can be fatal. Symptoms include high temperature, headache, stomach pain and constipation or diarrhoea.
On 6 April 2022, the municipal health service in Kennemerland was notified about an ongoing outbreak of fever and abdominal illness on the Liberty Ann and typhoid was quickly diagnosed. Bottled water was provided, food preparation on the ship halted and all the asylum seekers were moved to other accommodation.
All the asylum seekers, and most of the staff members, on the Liberty Ann were male. Twenty-five people were hospitalised and all recovered after treatment.
The municipal health service visited the ship six times to carry out microbiological investigations and technical inspections. Tests pointed to a common source of infection.
The study’s authors conclude: “A large outbreak of typhoid fever in the Netherlands was caused by sewage water containing Salmonella typhi leaking into a freshwater tank. Strict supervision of water quality is key to the health and safety of those on board ships. Water tanks and associated equipment must be properly maintained and subject to regular inspections.”
