Influenza epidemics were declared in the Bulgarian districts of Bourgas, Shoumen, Silistra and Stara Zagora on January 14.
The threshold for the declaration of a flu epidemic is reached when there is a rate of 290 out of 10 000 of the population of a district who have flu.
In Bourgas, the regional health inspectorate declared that the flu epidemic declaration would remain in force until January 18, when the inspectorate will meet again to decide whether to extend it.
As of January 15 in Bourgas, all schools will be closed.
Earlier, Bourgas mayor Dimitar Nikolov called for the declaration of the epidemic, after he held a meeting with the head of the regional health inspectorate, Dr Georgi Pazderov.
Pazderov said that currently, more than 15 per cent of pupils in the Bourgas district were not at school because they had flu.
Nikolov said that large-scale events would be cancelled.
In Silistra, where the incidence of flu is 329 out of 10 000, there will be restrictions on visitor admissions to medical facilities.
Schools where more than 30 per cent of the pupils have flu must suspend classes.
In Stara Zagora, the declaration takes effect as of January 15 and schools will be closed from January 16 to 18, the health inspectorate said.
There was an incidence of A H3N2 virus at a rate of 264.84 per 10 000 population in Stara Zagora, and all age groups were affected, the announcement said.
Bulgarian media reports on January 14 said that four other districts could face flu epidemics being declared: Yambol, Sofia, Sliven and Plovdiv.
(Photo: Iwan Beijes)