According to Estonia's Health Board, the cases of illness currently lack laboratory confirmation, however viral enteritis has been diagnosed based on clinical evidence.

Ida-Viru Central Hospital has not noted any outbreaks in disease recently.

The decision to quarantine the entire class in question was first and foremost a preventive measure, said Jõhvi Russian Basic School director Irina Šulgina. On Sept. 28, information spread at a meeting of the parents of the school's second grade children that two students had contracted an unusual virus that involved symptoms such as a sore throat and blistering skin rash.

"Then eight children from one class were absent from school on Monday and we decided that we have to take some kind of measures," Šulgina said. "We contacted the Health Board, which recommended quarantining the class."

According to the school director, the virus began to spread to students in other classes, and it was decided to close the school swimming pool as well, in order to help curb the spread of the virus.

50 children absent on Tuesday

"We have also decided that we have to disinfect all kinds of public areas in the school as well as inspect all classes," Šulgina added.

A total of 518 students attend the Jõhvi school, 21 of whom belong to the class that was quarantined. 50 students were absent from school on Tuesday.

According to Šulgina, doctors have said that symptoms of the viral infection can appear similar to those of the Coxsackievirus, but this has not yet been clinically confirmed.