Most of the people ill are children to the age of four and teenagers, however those most affected are the older people.
"Last week the incidence of disease has grown with influenza cases registered almost in every monitored territory. In five of them the intensity has surpassed 100 cases on 100,000," said epidemiologist Raina Nikiforova.
She advises people to wash hands frequently, not visit public spaces with many people and use public transportation more rarely.
Latvia has declared a flu epidemic since January 17.