Epidemiological data show decrease of influenza and other ARI activity in Russia in comparison with previous week. The nationwide ILI & ARI morbidity level (59.7 per 10 000 of population) was lower than the national baseline for season 2015-2016 (69.5) by 14.1%.
ILI and ARI epidemic thresholds were not exceeded in all of 59 cities collaborating with two WHO NICs in Russia.
Cumulative results of influenza laboratory diagnosis by different tests were submitted by 50 RBLs and two WHO NICs. According to these data as a result of 2054 patients investigation the overall proportion of respiratory samples positive for influenza was estimated as 6.9%, including 5.7% for influenza A(H1N1)pdm09 virus, 0.7% for influenza A(H3N2) virus, 0.4% for influenza A and 0.1% for influenza B virus.
Influenza and ARI morbidity data. Decreased influenza and other ARI activity was registered during the week 52.2015 in traditional surveillance system in Russia. The nationwide ILI & ARI morbidity level (59.7 per 10 000 of population) was lower than the national baseline by 14.1%.
Etiology of ILI & ARI morbidity. The overall proportion of respiratory samples tested positive for influenza was estimated as 6.9%. Percent of positive ARI cases of non-influenza etiology (PIV, adeno- and RSV) was estimated as 26.5% of investigated patients by IFA and 26.9% by PCR.
Antigenic characterization. Since start of 2015-2016 season 24 influenza virus was characterizated antigenically including 23 A(H1N1)pdm09 viruses and 1 influenza A(H3N2) virus. 23 (95.8%) influenza A(H1N1)pdm09 viruses were antigenically similar vaccine strain A/California/07/09. One influenza A(H3N2) virus was antigenically characterizated as A/Switzerland/9715293/2013-like.
In sentinel surveillance system clinical samples from 51 SARI and ILI/ARI patients were investigated by rRT-PCR. 2 influenza A(H1N1)pdm09 SARI cases and 1 influenza ILI/ARI case were detected.
