Iinfluenza and ARI intensity in Bulgaria was low during week No 40 (30.09.2013 - 06.10.2013) and the total incidence per 10,000 population was 52.94(during week No 39 the incidence was 37.87). From a total of 381 562 persons under surveillance, belonging to all age groups, a total of 2 020 ARI cases have been reported (during week No 39 the cases were 1 446). The incidence was highest in the age group 0-4 yrs (213.72 per 10,000 population), followed by age group of 5-14 yrs (182.15 per 10,000).