After a suspected serious norovirus outbreak in a tent at the Stuttgart Spring Festival, there are now more than 700 people affected. So far, the administration has registered around 727 cases of illness with the highly contagious gastrointestinal virus, the city announced on Thursday. A day earlier, the official figures reported were only around half as high. Of these, five cases of norovirus have so far been confirmed by laboratory diagnostics. The spokesman said that there is a high number of unreported cases among those affected because the infection is certainly passed on within the family.

The illnesses were not due to the food served in the affected festival tent, it said. “All samples taken by food control tested negative for norovirus.” There is also no evidence of violations of hygiene regulations. The city “assumes that the transmission occurred from person to person.”

The question of whether employees were infected with norovirus and could have triggered the outbreak was not yet fully clarified. According to the city, employees of the festival tent with and without symptoms were examined. Eleven employees without symptoms have already had negative test results, while eight employees with symptoms have had tests carried out, but so far without results.

According to its own information, the city immediately sent experts from the food control department and the health department to the festival. This prevented further spread. The operator of the affected festival tent is doing everything to ensure hygiene. There is daily basic cleaning and everything is being done to prevent a recurrence of the virus.

The operator of the affected tent told the "Stuttgarter Nachrichten" and "Stuttgarter Zeitung" (Thursday): "We had carefully checked all processes" - and added, "after the suspected cases even more than before." No cases of illness have been reported for days. There were no cancellations.

The city explained that the reported number of illnesses now suggests that the measures taken are effective. According to what we know so far, the infection rate in the festival tent was concentrated on the weekend. However, secondary illnesses in the private environment of sick visitors are possible.

Noroviruses cause nausea, vomiting and diarrhea, are very contagious and spread extremely quickly - especially in places where many people come together, such as kindergartens, retirement homes or hospitals. An infection is usually short and severe. Those affected feel weak, often have stomach aches, headaches and body aches, and sometimes a slight fever.

According to an expert, many people in a small space in a festival tent are perfect conditions for the spread of germs - including noroviruses. “It happens pretty quickly, experience tells us that,” said doctor Manfred Schmid. According to him, the virus is transmitted through touch and saliva. "So if you touch common objects, drink from the same glass and use the same dishes." Which often happens on the beer bench in a festival tent. Disinfectant wipes are only partially helpful because you constantly have to wipe everything down.

Large-scale norovirus outbreaks occur again and again. In nursing homes, entire wards are often affected within two days when an outbreak occurs. Large outbreaks are also observed on cruises. The incubation period is one to two days.

The city of Stuttgart advised those affected to contact the health department and their family doctor. Sick people should follow the recommended hygiene measures to prevent further spread. The tent can remain open, as a city spokesman announced. The operator is very cooperative.

The 84th Stuttgart Spring Festival began on Saturday with the traditional tapping of the barrel. For 23 days, the showmen have their rides, stalls and snack bars open, and there are drinks and performances in the festival tents.