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CDC Monthly Respiratory disease and Influenza Bulletin for Year 2023

Year 2023-December

In December 2023, National Influenza Surveillance sentinel sites collected 442 samples for Influenza and SARS-CoV-2 virus testing. There were 358 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 84 samples from Influenza-Like Illness (ILI) Surveillance at 17 sites in 16 provinces (Figure 1). Among 358 SARI specimens, 28 (7.8%) tested positive for influenza virus, of which 13 tested positive for B/Vic, 10 tested positive for A/H3N2, and 5 tested positive for A/H1N1pdm. Out of all the SARI samples collected for testing, 27 (7.5%) were positive for SARS-CoV-2. Of 84 ILI specimens, 19 (22.6%) were positive for influenza, of which 13 tested positive for B/Vic, and 6 tested positive for A/H3N2. 9 ILI samples (10.7%) were positive for SARS-CoV-2.


Year 2023-November

In November 2023, National Influenza Surveillance sentinel sites collected 492 samples for Influenza and SARS-CoV-2 virus testing. There were 400 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 92 samples from Influenza-Like Illness (ILI) Surveillance at 17 sites in 16 provinces (Figure 1). Among 400 SARI specimens, 54 (13.5%) tested positive for influenza virus, of which 27 tested positive for A/H1N1pdm, 19 tested positive for A/H3N2, 7 tested positive for B/Vic, and one tested positive for A/H5N1. Out of all the SARI samples collected for testing, 9 (2.3%) were positive for SARS-CoV-2. Of 92 ILI specimens, 22 (23.9%) were positive for influenza, of which 8 tested positive for A/H1N1pdm, 8 tested positive for A/H3N2, and 6 tested positive for B/Vic. Three ILI samples (3.3%) were positive for SARS-CoV-2.


Year 2023-October

In October 2023, National Influenza Surveillance sentinel sites collected 430 samples for Influenza and SARS-CoV-2 virus testing. There were 354 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 76 samples from Influenza-Like Illness (ILI) Surveillance at 17 sites in 16 provinces (Figure 1). Among 354 SARI specimens, 13 (3.7%) tested positive for influenza virus, of which 10 tested positive for A/H1N1pdm, 2 tested positive for A/H3N2, and one tested positive for A/H5N1. Out of all the SARI samples collected for testing, 3 (0.8%) were positive for SARS-CoV-2. Of 76 ILI specimens, 15 (19.7%) were positive for influenza, of which 9 tested positive for A/H1N1pdm, and 6 tested positive for A/H3N2. All ILI samples were tested negative for SARS-CoV-2.


Year 2023-September

In September 2023, National Influenza Surveillance sentinel sites collected 581 samples for Influenza and SARS-CoV-2 virus testing. There were 496 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 85 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Among 496 SARI specimens, 12 (2.4%) tested positive for influenza A/H1N1pdm, 2 (0.4%) tested for A/H3N2, and 1 (0.2%) tested positive for SARS-CoV-2. Of 85 ILI specimens, 6 (7.0%) were tested positive for A/H1N1pdm, and 4 (4.7%) were positive for A/H3N2. All ILI samples were tested negative for SARS-CoV-2.


Year 2023-August

In August 2023, National Influenza Surveillance sentinel sites collected 711 samples for Influenza and SARS-CoV-2 virus testing. There were 622 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 89 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Among 622 SARI specimens, 29 (4.7%) tested positive for influenza A/H1N1pdm, and 2 (0.3%) was positive for SARS-CoV-2 detected in SARI surveillance. Of 89 ILI specimens, 24 (26.9%) were tested positive for A/H1N1pdm, and 1 (1.1%) was positive for SARS-CoV-2.


Year 2023-July

In July 2023, National Influenza Surveillance sentinel sites collected 446 samples for Influenza and SARS-CoV-2 virus testing. There were 356 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 90 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Among 356 SARI specimens, 59 (16.6%) tested positive for influenza A/H1N1pdm, and 7 (2.0%) was positive for SARS-CoV-2 detected in SARI surveillance. Of 90 ILI specimens, 27 (30.0%) were tested positive for A/H1N1pdm, 1 (1.1%) was tested positive for B/Victoria and 1 (1.1%) was positive for SARS-CoV-2.


Year 2023-June

In June 2023, National Influenza Surveillance sentinel sites collected 633 samples for Influenza and SARS-CoV-2 virus testing. There were 533 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 100 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Among 533 SARI specimens, 116 (21.8%) tested positive for influenza, of which 115 were positive for A/H1N1pdm, and 1 was positive for A/H3N2. In addition, 72 (13.5%) samples were positive for SARS-CoV-2 detected in SARI surveillance. Of 100 ILI specimens, 42 (42.0%) were tested positive for influenza A/H1N1pdm, and 14 (14.0%) was positive for SARS-CoV-2.


Year 2023-May

In May 2023, National Influenza Surveillance sentinel sites collected 313 samples for Influenza and SARS-CoV-2 virus testing. There were 253 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 60 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Among 253 SARI specimens, 65 (25.7%) tested positive for influenza, of which 63 were positive for A/H1N1pdm, and 2 were positive for A/H3N2. In addition, 47 (18.6%) samples were positive for SARS-CoV-2 detected in SARI. Of 60 ILI specimens, 12 (20.0%) were tested positive for influenza A/H1N1pdm, and 17 (28.3%) was positive for SARS-CoV-2.


Year 2023-April

In April 2023, National Influenza Surveillance sentinel sites collected 233 samples for Influenza and SARS-CoV-2 virus testing. There were 180 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 53 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Among 180 SARI specimens, 11 (6.1%) tested positive for influenza A/H1N1pdm, and 2 (1.1%) were positive for SARS-CoV-2. Of 53 ILI specimens, 6 (11.3%) were tested positive for influenza A/H1N1pdm, 1 (1.9%) was negative for SARS-CoV-2.


Year 2023-March

In March 2023, National Influenza Surveillance sentinel sites collected 369 samples for Influenza and SARS-CoV-2 virus testing. There were 286 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 83 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Of 9 (3.1%) SARI samples tested positive for influenza viruses, 8 were positive for A/H1N1pdm, and 1 positive for A/H3N2. There was no sample tested positive for SARS-CoV-2 in SARI samples. Of 5 (6.0%) ILI specimens tested positive for influenza, 4 were positive for B/Vic and 1 positive for A/H1N1pdm. In addition, all ILI samples were negative for SARS-CoV-2.


Year 2023-February

In February 2023, National Influenza Surveillance sentinel sites collected 339 samples for Influenza and SARS-CoV-2 virus testing. There were 276 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 63 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Of 5 (1.8%) SARI samples tested positive for influenza viruses, 1 was positive for B/Vic, 3 positives for A/H1N1pdm and 1 positive for A/H5N1. There were 9 (3.3%) positive for SARS-CoV-2 in SARI samples. Of 3 (4.7%) ILI specimens tested positive for influenza, 2 were positive for A/H1N1pdm and 1 positive for B/Vic. In addition, there was no SARS-CoV-2 detected in ILI specimens.


Year 2023-January

In January 2023, National Influenza Surveillance sentinel sites collected 352 samples for Influenza and SARS-CoV-2 virus testing. There were 293 samples from Severe Acute Respiratory Illness (SARI) at 9 sites in 5 provinces (Figure 1). There were 59 samples from Influenza-Like Illness Surveillance at 17 sites in 16 provinces (Figure 1). Of 2 (0.7%) SARI samples tested positive for influenza viruses, all were positive for B/Vic. There were 17 (5.8%) positive for SARS-CoV-2 in SARI samples. Of 9 (14.0%) ILI specimens tested positive for influenza, 8 were positive for B/Vic and 1 positive for A/H3N2. In addition, 1 (1.7%) sample detected with positive SARS-CoV-2 in ILI specimens.