Packaged Curd and Food Poisoning in Kutch: An Outbreak Across Logistically Challenged Stations

Packaged curd is a rarely reported source of food poisoning. We analyzed a simultaneous outbreak across two stations located 95 km apart in the Kutch region of Gujarat.

A descriptive observational study was conducted using interviews and clinical data from affected individuals. Case identification, symptom analysis, food consumption history, and laboratory investigations were used to trace the source and cause of the outbreak.

A total of 280 individuals-including personnel and family members-reported gastrointestinal illness over a four-day period following the consumption of curd or curd-based food items at both affected locations. The majority of cases were male (71%) and within the age group of 15-45 years (77%). All reported cases were epidemiologically linked to curd procured from a common dairy source serving the Kutch region. The highest food-specific attack rate was observed for curd, at 33.4%. The median incubation period ranged from 18 to 23.5 hours across the two stations. The predominant clinical manifestations included loose stools (78.2%), abdominal pain (65%), and fever (59.6%). Microbiological analysis confirmed the presence of Salmonella enterica serovar Chester in stool samples from affected individuals. Although Escherichia coli was detected in the curd samples, the clinical profile of the cases and the epidemiological pattern were strongly indicative of Salmonella as the primary causative pathogen.

This large Kutch outbreak has an unusual source of contamination with rare Salmonella enterica serovar Chester in packaged curd, thereby contributing to a rare identification in foodborne outbreaks. Collaborative efforts in a unique way across public health, food safety, and microbiology were important for the timely identification of the agent and source. The study accentuates the importance of keeping suspicion high and strong interagency protocols in place to effectively manage an outbreak.