WHO NIC at Research Institute of Influenza and D.I. Ivanovsky Institute of Virology INTEGRATED DATA OF INFLUENZA MORBIDITY AND DIAGNOSIS

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1 WHO NIC at Research Institute of Influenza and D.I. Ivanovsky Institute of Virology 1 of 7 Year: 2019 Week: 8 Period: Influenza and ARI morbidity data Epidemiological data show decrease of influenza and other ARI activity in Russia in comparison with previous week. The nationwide ILI and ARI morbidity level (85.8 per of population) was above then national baseline (72.2) by 18.8%. ILI and ARI epidemic thresholds were exeeded in 19 of 61 cities collaborating with two NICs of Russia. Exceeding of morbidity epidemic thresholds for overall population - No data - less 20% % - 50% and more

2 2 of 7 Cumulative number of diagnosed influenza cases Cumulative results of influenza laboratory diagnosis by different tests were submitted by 55 RBLs and two WHO NICs. According to these data as a result of 7482 investigation 2399 (32.1%) respiratory samples positive for influenza were detected including 1105 influenza A(H1N1)pdm09 cases in 51 cities, 932 influenza A(H3N2) cases in 53 cities, 344 influenza type A cases in 6 cities and 18 influenza type B cases in 7 cities. Results of influenza diagnosis - No data - No detection - H1pdm09 - H1pdm09+H1 - H1pdm09+B - H1pdm09+B+H1 - H1pdm09+H3 - H1pdm09+H3+H1 - H1pdm09+H3+B - H1pdm09+H3+H1+B - H1 - B - B+H1 - H3 - H3+H1 - H3+B - H3+H1+B

3 3 of 7 Influenza Virus Isolation - B - A(H1N1) - A(H3N2) - A(H1N1)pdm09

4 4 of 7 Influenza Virus Antigen Detection by Immunofluorescence Assay (IFA) - B - A(H1N1) + A(H1N1)pdm09 - A(H3N2) - PIV - AD - RS

5 5 of 7 Influenza Virus RNA Detection by RT-PCR - B - A(H1N1) - A(H3N2) - A(H1N1)pdm09 - PIV - AD - RS

6 6 of 7 Table N1. Influenza Virus Isolation viruses isolated H1 H3 B H1pdm09 Untyped virus BL of RII (%) 0,0 8,5 0,0 24,5 0,0 32,9 BL of IV (%) 0,0 3,8 0,0 13,8 0,0 17,5 TOTAL (%) 0,0 6,9 0,0 20,9 0,0 27,8 Total Table N2. Influenza Virus Antigen Detection by Immunofluorescence assay (IFA) Influenza Parainfluenza H1+H1pdm09 H3 B I II III AD RS Total BL of RII (%) 7,9 2,1 0,1 2,6 5,0 1,9 4,4 2,4 26,3 BL of IV (%) 8,6 2,3 0,0 1,1 4,0 8,6 5,1 1,7 31,4 TOTAL (%) 8,0 2,1 0,1 2,4 4,9 2,6 4,5 2,3 26,9 Table N3. Influenza Virus RNA detection by RT-PCR A (not subtyped) Influenza H1 H3 H5 B H1pdm09 PIV AD RS BL of RII / / / / / / / / / 3616 (%) 6,2-14,0 0,0 0,3 15,4 0,9 1,0 2,2 BL of IV / / / / 67 4 / / / / / 418 (%) 0,0-15,4 0,0 0,5 16,7 1,4 3,6 4,5 TOTAL / / / / / / / / / 4034 (%) 5,4-14,2 0,0 0,3 15,6 0,9 1,3 2,4 Table N4. Cumulative Diagnosed Influenza Cases H1 H1+H1pdm09 (IFA) diagnosed influenza cases H3 A (not subtyped) B H1pdm09 Total BL of RII (%) 0,0 1,7 12,2 5,2 0,2 14,6 32,2 BL of IV (%) 0,0 1,7 14,6 0,0 0,5 16,2 31,2 TOTAL (%) 0,0 1,7 12,5 4,6 0,2 14,8 32,1

7 7 of 7 Conclusion Influenza and ARI morbidity data. Decreased influenza and other ARI activity was registered during the week in traditional surveillance system in Russia. The nationwide ILI and ARI morbidity level (85.8 per of population) was above then national baseline (72.2) by 18.8%. Etiology of ILI & ARI morbidity (32.1%) respiratory samples positive for influenza were detected including 1105 influenza A(H1N1)pdm09 cases in 51 cities, 932 influenza A(H3N2) cases in 53 cities, 344 influenza type A cases in 6 cities and 18 influenza type B cases in 7 cities. Antigenic characterization. 227 influenza viruses were characterized antigenically in Moscow and Saint- Petersburg NICs including 170 influenza A(H1N1)pdm09, 56 influenza A(H3N2) strains and 1 influenza type B strain. All influenza A(H1N1)pdm09 viruses were related to influenza A/Michigan/45/2015 vaccine strain, 167 influenza A(H3N2) viruses were like to A/Singapure/INFIMN /2016 vaccine strain, 3 influenza A(H3N2) viruses were antigenically different from a reference virus and had to show a decrease of 8-fold HI titre with the respective post-infection antiserum. One influenza B virus belonged to Victoria lineage and antigenically related to B/Colorado/06/2017 vaccine strain. Genetic characterization. Genetic analysis of 101 influenza viruses HA from isolate and clinical samples including 58 influenza A(H1N1)pdm09 strains, 42 influenza A(H3N2) strains and 1 influenza type B virus were performed. All A(H1N1)pdm09 viruses were like to the vaccine strain A/Michigan/45/2015 (6B.1clade). All A(H3N2) viruses were like A/ALsace/1746/2018 reference strain (3C.2a1b subgroup). Influenza B strain of Victoria lineage belonged to subclade V1A.1 with two amino acid deletion ( ) in HA molecule. Susceptibility to antivirals. All influenza A viruses were susceptible to oseltamivir. One influenza B/Arkhangelsk/RII-01/2018 virus had reduced susceptibility to oseltamivir. Percent of positive ARI cases of non-influenza etiology (PIV, adeno- and RSV) was estimated as 16.7% of by IFA and 4.6% by PCR. In sentinel surveillance system clinical samples from 94 SARI and ILI/ARI were by rrt-pcr. 18 (37.5%) cases were associated with influenza, including 13 influenza A(H1N1)pdm09 cases and 5 A(H3N2) cases. Among 46 ILI/ARI 25 (54.3%) influenza cases were recognized, including 15 influenza A(H1N11)pdm09 cases and 10 A(H3N2) cases. Anna A.SOMININA, professor Deputy Chief of the WHO National Influenza Center of Russia, St.-Petersburg Elena I.BURTSEVA, DMS, Chief of the Laboratory of Etiology and Epidemiology of Influenza, WHO National Influenza Center of Russia, Moscow