Influenza and ARI intensity in Bulgaria was low during week No 04 (25.01.2021 – 31.01.2021).  The total incidence per 10,000 population was 47,06 (during week No 03 the incidence was 43,87  ). From a total of 378 884 persons under surveillance, belonging to all age groups, a total of 1783 ARI cases have been reported (during week No 03 the cases were 1662). The incidence was highest in the age group 0-4 yrs (234.59 per 10,000 population), followed by age group of 5-14 yrs (124.14 per 10,000 population).