A suspected outbreak of a rare and extremely dangerous food poisoning in Moscow left more than 120 people seeking medical help and at least 30 in intensive care, health officials said on Monday.

The patients were admitted to hospital with suspected foodborne botulism, a life-threatening condition that attacks the nervous system and can cause respiratory failure and paralysis.

Russian authorities said the toxic outbreak came from salads distributed by a popular online delivery service, which on Sunday temporarily suspended its operations amid a criminal investigation.

“In total 121 people sought medical help,” state news agencies quoted Anastasia Rakova, the deputy mayor of Moscow, as saying on Monday.

“At the moment 55 people are in a serious condition, 30 of them in intensive care,” she added.

The city’s consumer and health watchdog, Rospotrebnadzor, said on Saturday it was conducting an “epidemiological investigation into suspected cases of botulism.”

The Moscow prosecutor’s office said it had launched a criminal investigation into a breach of consumer safety standards.

Deputy Mayor Rakova said there was “no threat to the lives” of those who had been hospitalized thanks to timely medical intervention.

The food delivery company linked to the outbreak, Kuchnia Na Rayone (“local kitchen”), said it had identified a “potential risk incident” with a salad that used tinned beans, and it had suspended orders.

What is botulism?

Botulism is an extremely rare condition, typically caused by improperly processed food and linked to canned and preserved goods.

According to the World Health Organization, foodborne botulism is a “serious, potentially fatal disease.”  It does not pass between people.

Early symptoms include fatigue, vertigo, blurred vision, dry mouth, and difficulty in swallowing and speaking, according to WHO. 

“Incidence of botulism is low, but the mortality rate is high if prompt diagnosis and appropriate, immediate treatment is not given,” WHO states.

Last year, one woman died and eight other people — including a University of Colorado graduate — were in intensive care after an outbreak of botulism linked to a wine bar in France. 

There were 82 confirmed cases of botulism across the European Economic Area (EEA) in 2021, the last year of available data, according to the European Centre for Disease Prevention and Control.