Truong Thi Phuong's stall on Phan Chau Trinh Street in Hoi An will be suspended for at least five months, Mai Van Muoi, director of the Quang Nam Department of Health, said in a proposal submitted to provincial authorities for approval.
Inspectors of the health department said the eatery did not have sanitary waste collection and storage facilities and its cooking tools did not meet hygiene requirements.
Food testing results also showed that the stall violated food safety regulations in processing, supplying and selling banh mi to customers.
The department said a total of 3,600 people bought banh mi from the eatery on September 11 and September 12. Later, 313 of them including 103 foreigners showed symptoms of headache, fever, abdominal pain, and diarrhea.
273 people had to be hospitalized, all of whom have since been discharged. There were no deaths.
The food poisoning was caused by Salmonella bacteria that had been found in the char siu (BBQ pork) and various herbs and vegetables in banh mi samples taken from Phuong's stall, the department concluded.
Phuong's banh mi stall is popular among foreign tourists and has often received rave reviews from international media outlets.