An outbreak of Legionnaire’s disease at a Lisbon suburb that has killed ten people and infected over 300 others over the past two weeks has ended, Portugal’s health minister said.
“The source of the outbreak has been eliminated and we can declare that it has been put out,” Health Minister Paulo Macedo told a news conference.
The outbreak – which the World Health Organisation last week called a “major public health emergency” – started on 7 November with an initial case detected in Vila Franca de Xira, about 30km north of Lisbon.
The authorities say the outbreak was very likely caused by bacteria found in the refrigeration system of a fertiliser factory Adubos de Portugal.
The environment ministry has said the factory has been tested to see if there was negligence in maintenance and if any “environmental crime” had been committed.
A total of 336 people were infected in the outbreak, of which seven men and three women aged 59-89 died, the health directorate said in a statement.
Over half of those infected have already left hospital but 38 people remain in intensive care.
Portugal’s government said the outbreak was the third biggest in the history of the disease in terms of the number of people infected.
The disease is not contagious and cannot be spread directly from person to person.
It can multiply in water and air conditioning systems, including humidifiers, whirlpools and spas.
Legionella contamination is usually caught by breathing in small droplets of contaminated water.
Large buildings such as hotels, hospitals, museums and office blocks are more vulnerable to legionella contamination because they have larger, more complex water supply systems in which the bacteria can quickly spread.
Legionnaire’s disease was discovered in the United States in 1976 after a convention of the American Legion, a military veterans group, at which 29 people died.