Influenza and ARI intensity in Bulgaria was lower than medium during week No 52 (24.12.2007 - 30.12.2007). The total incidence per 10, 000 population was 46.80 (during the week 51 the incidence was 91.85). From a total of 378,212 persons under surveillance, belonging to all age groups, a total of 1,770 ARI cases have been reported (during the week 51 they were 3,474).   The incidence is highest in the age group 0-4 ys (218.08 per 10,000 population), followed by age group of 5-19 ys old (95.95 per 10,000).  The highest incidence has been reported in: Montana (140.63), Pazardjik (133.93), Smolyan (128.69), Stara Zagora (124.28) and Targovishte (148.90).