Around 20 students and one teacher from the "Nevena Georgieva-Dunja" primary school in Kisela Voda reported stomach trouble - nausea, vomiting and diarrhoea. The case alarmed parents, and health services are now trying to determine whether this is food poisoning or a viral infection.

Of the children, about 15 were examined at the Children's Diseases Clinic; most had mild symptoms and were sent home to recover. One child was briefly hospitalised, then discharged once stable. Another four children and one adult were seen at the Infectious Diseases Clinic, with no need to keep them in.

Here's the curious part of the epidemiological inquiry: the affected students did not eat the same food. They come from different age groups and ate their meals in different places, some of them outside the school. That makes the easy verdict - "blame the school kitchen" - much harder, and puts the actual source of the problem in question.

And then comes the familiar weakness: coordination. The Kisela Voda municipality says it immediately notified the Centre and the Institute for Public Health - but both institutions said that, by the time the story broke, they had received no official report. When 20 kids end up with symptoms and the institutions can't agree on who told whom, the problem isn't only medical. It's a system that's supposed to react fast, but instead first checks whose job it is.