British holidaymakers are being warned about an outbreak of a deadly disease that has already claimed four lives. The European Centre for Disease Prevention and Control (ECDC) and the British Foreign Office-backed website Travel Health Pro have highlighted the problem.

Yesterday (23 August), a new update from the ECDC confirmed the presence of Legionnaires’ disease in several areas within the city limits of Milan, in particular in Corsico and Buccinasco in the Lombardy region. A dozen people are currently receiving hospital treatment.

As of August 19, statistics show that there were 53 confirmed infections and four deaths. Authorities are currently taking tough measures to stop the disease from spreading further and prevent new cases. Authorities said people in the area could be particularly at risk as the source has not yet been identified.

The ECDC has recorded cases ranging in age from 26 to 94 years and stated that all four deceased were over 70 years old and had additional health complications.

There are currently 12 patients being treated in hospital, and 37 of the admitted patients have now returned home. Authorities also report four deaths in connection with the outbreak.

Extensive investigations are currently underway to determine the origin. The ECDC announced that “epidemiological, microbiological and environmental investigations are ongoing. Water samples were collected from several sampling points of the municipal water supply system, both from the water systems of patients/control cases’ private households and from cooling towers.”

“Collection of respiratory specimens from patients and typing of isolated Legionella strains are continuing to assist in identifying the source of the outbreak. Public health measures to prevent transmission and emergence of new cases continue to be implemented, including chemical disinfection of the municipal water supply system and private residences with chlorine.”

Legionnaires’ disease is caused by inhaling water vapor that contains Legionella bacteria. The risk is greater for people over 50, those with weakened immune systems, or those with pre-existing medical conditions.