Outbreak of type A foodborne botulism

The purpose — to study the clinical and epidemiological features of the outbreak of type A foodborne botulism in Kazan. Material and methods. We analyzed 22 case histories of patients with botulism hospitalized in the Republic Clinical Hospital for Infectious Diseases named after A.F. Agafonov from 06/16/24 to 06/26/24. Results. All patients ate vacuum-packed «Lobio salad with beans» ordered from a food delivery service from 12.06 to 17.06.24. The patients were predominantly young and actively working people. The average age of patients was 33.1 (9.3) years (Min 21; Max 65). There were 15 (66.7%) women and 7 (33.3%) men. The incubation period duration was 2.2 (1.9), (Min 1; Max 8) days. The onset of botulism with neurological symptoms occurred in 82%, with symptoms of gastroenteritis and mixed type — in 9% of cases. In 47.6% of cases, diagnoses at the prehospital stage were incorrect. Mild botulism was diagnosed in 7 (32%), moderate — in 5 (23%), severe — in 10 (45%) people. Changes in laboratory blood parameters characteristic of bacterial infection were detected in patients with severe botulism. Type A botulinum toxin was determined in a biological sample on mice. Two (9.5%) patients with severe botulism and aspiration pneumonia underwent mechanical ventilation. There were no fatalities. Conclusion. Mass botulism may develop when consuming «ready-to-eat» food supplied via delivery services, which may create a public health emergency. Knowledge of the clinical picture of botulism, as well as the epidemiological investigation of cases, is crucial for early diagnosis and timely administration of botulinum serum. Governmental food safety controls are essential in preventing such foodborne outbreaks.