Iinfluenza and ARI intensity in Bulgaria was low during week No 38 (16.09.2013 - 22.09.2013) and the total incidence per 10,000 population was 30.58(during week No 37 the incidence was 24.40). From a total of 381 562 persons under surveillance, belonging to all age groups, a total of 1 167 ARI cases have been reported (during week No 37 the cases were 931). The incidence was highest in the age group 0-4 yrs (153.81 per 10,000 population), followed by age group of 5-14 yrs (92.18 per 10,000).