National Weekly Bulletin

NATIONAL WEEKLY INFLUENZA BULLETIN OF THE RUSSIAN FEDERATION

week 46 of 2022 (14.11.22 - 20.11.22)

Summary

Influenza and ARI incidence data. Influenza and other ARI activity increase of influenza and other ARI activity in Russia in comparison with previous week. The nationwide ILI and ARI morbidity level (77.8 per 10 000 of population) was higher than national baseline (70.0) by 11.1%.

Etiology of ILI & ARI. Among 3620 patients investigation 105 (2.9%) respiratory samples were positive for influenza, including 90 cases of influenza A(H1N1)pdm09 in 19 cities, 2 cases of influenza A(H3N2) in 2 cities and 13 cases of influenza B in 8 cities.

2 influenza A(H1N1)pdm09 viruses were isolated on MDCK cell culture, including: in Moscow (1) and Saint-Petersburg (1). Since the beginning of the season, 4 viruses A(H1N1)pdm09 have been isolated.  

Antigenic characterization. Since the beginning of the season, 3 influenza A(H1N1)pdm09 have been antigenically characterized by the NICs (Moscow and Saint-Petersburg). All viruses were antigenically similar to reference strain A/Victoria/2570/2019 (H1N1)pdm09. 

ARVI detections. The overall proportion of respiratory samples tested positive for other ARVI (PIV, ADV, RSV, RhV, CoV, MPV, BoV) was estimated in total as 20.5% (PCR).

In sentinel surveillance system clinical samples from 75 SARI patients were investigated by rRT-PCR for influenza, among them 11 (14.7%) cases of influenza recognized including 9 cases of A(H1N1)pdm09 influenza and 2 cases of B influenza. 62 SARI patients were investigated for ARVI by rRT-PCR, among them 16 (25.8%) cases of ARVI recognized including 1 case of PIV, 5 cases of ADV, 3 cases of RSV, 4 cases of RhV, 1 case of CoV, 1 case of MPV and 1 case of BoV infection. 67 SARI patients were investigated for SARS-CoV-2 by rRT-PCR, among them no positive cases recognized.

Clinical samples from 40 ILI/ARI patients were investigated for influenza by rRT-PCR, among them no positive cases recognized. Among 29 ILI/ARI samples 14 (48.3%) cases positive for ARVI detected including 2 cases of PIV, 1 case of ADV, 1 case of RSV, 4 cases of RhV, 4 cases of CoV, 1 case of MPV and 1 case of BoV infection. 2 (5.9%) of 34 ILI/ARI patients were positive for coronavirus SARS-CoV-2. 

COVID-19. Totally 21 550 982 cases and 391 622 deaths associated with COVID-19 were registered in Russia including 5 631 cases and 54 deaths in last 24 hours (on 12:00 of 23.11.2022). According to the data obtained by NIC in Saint-Petersburg totally 9 957 clinical samples were PCR investigated in last week. Among them coronavirus SARS-CoV-2 detected in 765 (7.7%) cases.

Influenza and ARI morbidity data

Epidemiological data showed increase of influenza and other ARI activity in Russia in comparison with previous week. The nationwide ILI and ARI morbidity level (77.8 per 10 000 of population) was higher than national baseline (70.0) by 11.1%.

Incidence rate of clinically diagnosed influenza increased comparing to previous week and amounted to 0.29 per 10 000 of population, it was higer than pre-epidemic MEM baseline (0.060).

Hospitalization rate of clinically diagnosed influenza increased comparing to previous week and amounted to 0.076 per 10 000 of population, it was higer than pre-epidemic MEM baseline (0.040).

Influenza and ARVI laboratory testing results

Cumulative results of influenza laboratory diagnosis by rRT-PCR were submitted by 45 RBLs and two WHO NICs. According to these data as a result of 3620 patients investigation 105 (2.9%) respiratory samples were positive for influenza, including 90 cases of influenza A(H1N1)pdm09 in 19 cities, 2 cases of influenza A(H3N2) in 2 cities and 13 cases of influenza B in 8 cities.

2 influenza A(H1N1)pdm09 viruses were isolated on MDCK cell culture, including: in Moscow (1) and Saint-Petersburg (1). Since the beginning of the season, 4 viruses A(H1N1)pdm09 have been isolated.

Antigenic characterization. Since the beginning of the season, 3 influenza A(H1N1)pdm09 have been antigenically characterized by the NICs (Moscow and Saint-Petersburg). All viruses were antigenically similar to reference strain A/Victoria/2570/2019 (H1N1)pdm09.

ARVI detections. The overall proportion of respiratory samples tested positive for other ARVI (PIV, ADV, RSV, RhV, CoV, MPV, BoV) estimated as 20.5% of investigated samples by PCR.

Table 1. Results of influenza and other ARVI detection by RT-PCR in Russia, week 46 of 2022

COVID-19. Totally 21 550 982 cases and 391 622 deaths associated with COVID-19 were registered in Russia including 5 631 cases and 54 deaths in last 24 hours (on 12:00 of 23.11.2022). According to the data obtained by NIC in Saint-Petersburg totally 9 957 clinical samples were PCR investigated in last week. Among them coronavirus SARS-CoV-2 detected in 765 (7.7%) cases.

Table 2. Results of influenza viruses isolation in Russia, week 46 of 2022

Sentinel influenza surveillance

Clinical samples from 75 SARI patients were investigated by rRT-PCR for influenza, among them 11 (14.7%) cases of influenza recognized including 9 cases of A(H1N1)pdm09 influenza and 2 cases of B influenza. 62 SARI patients were investigated for ARVI by rRT-PCR, among them 16 (25.8%) cases of ARVI recognized including 1 case of PIV, 5 cases of ADV, 3 cases of RSV, 4 cases of RhV, 1 case of CoV, 1 case of MPV and 1 case of BoV infection. 67 SARI patients were investigated for SARS-CoV-2 by rRT-PCR, among them no positive cases recognized.

Clinical samples from 40 ILI/ARI patients were investigated for influenza by rRT-PCR, among them no positive cases recognized. Among 29 ILI/ARI samples 14 (48.3%) cases positive for ARVI detected including 2 cases of PIV, 1 case of ADV, 1 case of RSV, 4 cases of RhV, 4 cases of CoV, 1 case of MPV and 1 case of BoV infection. 2 (5.9%) of 34 ILI/ARI patients were positive for coronavirus SARS-CoV-2.