Week No 4

26.01.2026
In week 4, 2026y, 5200 new cases of acute respiratory infections and influenza are registered among an observed population of 347,913 people, which represents an incidence rate of 149.46 per 10,000 population. In the previous week, 5055 cases of acute respiratory diseases infections and influenza were registered among an observed population of 347,913 people, which corresponds to an incidence rate of 145.29 per 10,000 population. The country average incidence and by age groups remains at levels comparable with the previous week and is again the highest in the age groups 0-4 years (567.09 per 10,000 population), and 5-14 years (471.06 per 10,000 population).
By districts, the trend in the dynamics of the incidance rate is as follows: Epidemic levels are reported for Burgas district (319.24 per 10,000 population) and Plovdiv (225.18 per 10,000 population), where the number of new cases is rising. Varna and Dobrich districts are dropping off the epidemic zone, with incidence rate decreasing compared to the previous week. The values for Veliko Tarnovo and Smolyan district are comparable with the previous week, and in Sliven district the number of new cases is higher than the previous week. The incidence rate is rising in Yambol, Montana, Sofia-district (with a slight decrease from the previous week), Pleven, Targovishte and Ruse. The incidence rate for the remaining districts is medium or low.

During week 4, 522 clinical samples from patients with ARI were tested by Real Time PCR at the National Reference Laboratory for Influenza and ARI. 132 cases of influenza A(H3N2) virus,  13 cases of influenza A/H1N1 (2009) and 1 case of influenza B/Victoria virus were confirmed.
In children under 5 years of age, the following were confirmed in the 371 clinical samples tested: influenza virus A/H3N2 (102), influenza virus A/H1N1 (2009) (10), AdV (5), RSV (14), PIV (5), and other viruses (26).