More than 30 people have needed hospital treatment in Italy for suspected botulism intoxication.

The 35 patients seen at the emergency department of the Giglio Foundation hospital in Cefalù, a city in northern Sicily, had the same meal in a canteen.

Currently, 24 patients are being looked after in three Sicilian hospitals with seven in intensive care and four under observation in an emergency room. Admissions started on Wednesday this past week.

Suspicion falls on food for construction workers
Those sick are workers from Toto Costruzioni Generali and initial investigations point toward a shared meal of salad containing tuna, tomato and mozzarella.

The firm has been operating for more than 50 years in the construction sector specializing in tunnels and the building of large bridges and viaducts.

In a statement quoted by Italian media, the company said it has provided assistance for employees hospitalized for food poisoning and their families and was seeking clarity on the incident. Its own doctors were also in contact with hospital staff.

The canteen at the construction site, which was provided with meals by a catering service, is being investigated by health officials in Palermo and local police.

Samples taken from patients in the emergency room were sent for confirmation of the diagnosis to the Istituto Superiore di Sanità in Rome.

More than 10 discharged patients have been monitored via telephone follow up by the Poison Control Center in the town of Pavia.

Italy is the European country with the highest number of botulism cases. From 1986 to June 2019, 342 botulism incidents involving 501 people were confirmed by laboratory testing, according to data reported by the National Reference Center for Botulism (CNRB).

Botulism is a rare but life-threatening condition caused by toxins produced by Clostridium botulinum bacteria. In foodborne botulism, symptoms generally begin 18 to 36 hours after eating a contaminated food. However, they can start as soon as six hours after or up to 10 days later.

It can cause symptoms including general weakness, dizziness, double-vision, and trouble with speaking or swallowing. It paralyzes respiratory muscles so most patients must be placed on life support. Difficulty in breathing, weakness of other muscles, abdominal distention and constipation may also occur. People experiencing these problems should seek immediate medical attention.