BOA1

Featured post

#Avian #Influenza #H7N9 in #China: Preventing the Next #SARS (@WHO, Apr. 2 ‘17)

  Title : #Avian #Influenza #H7N9 in #China: Preventing the Next #SARS. Subject : Avian Influenza, H7N9 subtype (Asian Lineage), poultry e...

27 Jan 2017

Weekly #US #Influenza #Surveillance #Report - 2016-17 Season, Wk 3 ending Jan. 21, ‘17 (@CDCgov, summary)

 

Title: Weekly #US #Influenza #Surveillance #Report - 2016-17 Season, Wk 3 ending Jan. 21, ‘17.

Subject: Human Influenza Viruses, Seasonal Epidemic, US CDC weekly activity surveillance report.

Source: US Centers for Disease Control and Prevention (CDC), full page: (LINK). Excerpts, edited.

Code: [     ]

_____

Weekly U.S. Influenza Surveillance Report - 2016-2017 Influenza Season Week 3 ending January 21, 2017

___

|-- Full report also available as PDF –|

___

All data are preliminary and may change as more reports are received.

 

Synopsis:

  • During week 3 (January 15-21, 2017), influenza activity increased in the United States.
    • Viral Surveillance:
      • The most frequently identified influenza virus subtype reported by public health laboratories during week 3 was influenza A (H3).
      • The percentage of respiratory specimens testing positive for influenza in clinical laboratories increased.
    • Pneumonia and Influenza Mortality:
      • The proportion of deaths attributed to pneumonia and influenza (P&I) was above the system-specific epidemic threshold in the National Center for Health Statistics (NCHS) Mortality Surveillance System.
    • Influenza-associated Pediatric Deaths:
      • Three influenza-associated pediatric deaths were reported.
    • Influenza-associated Hospitalizations:
      • A cumulative rate for the season of 15.4 laboratory-confirmed influenza-associated hospitalizations per 100,000 population was reported.
    • Outpatient Illness Surveillance:
      • The proportion of outpatient visits for influenza-like illness (ILI) was 3.4%, which is above the national baseline of 2.2%.
      • All 10 regions reported ILI at or above their region-specific baseline levels.
      • New York City and 10 states experienced high ILI activity; 10 states experienced moderate ILI activity; Puerto Rico and 17 states experienced low ILI activity; 13 states experienced minimal ILI activity, and the District of Columbia had insufficient data.
    • Geographic Spread of Influenza:
      • The geographic spread of influenza in Puerto Rico and 37 states was reported as widespread; Guam and 12 states reported regional activity; the District of Columbia and one state reported local activity; and the U.S. Virgin Islands reported no activity.

 

National and Regional Summary of Select Surveillance Components

[HHS Surveillance Regions* - Data for current week: Out-patient ILI† - Number of jurisdictions reporting regional or widespread activity§ - % respiratory specimens positive for flu in clinical laboratories‡ - Data cumulative since October 2, 2016 (week 40): A(H1N1)pdm09 - A (H3) - A (Subtyping not Performed) - B Victoria lineage - B Yamagata lineage - B lineage not performed - Pediatric Deaths]

Influenza test results from public health laboratories only

  • Nation – Elevated - 51 of 54 - 18.4% – 258 - 9,329 – 220 – 271 – 249 – 202 – 8
    • Region 1 – Elevated - 6 of 6 - 14.5% – 20 – 524 – 0 – 6 – 12 – 6 – 0
    • Region 2 – Elevated - 3 of 4 - 18.6% – 2 – 452 – 11 – 17 – 9 – 26 – 0
    • Region 3 – Elevated - 5 of 6 - 12.2% – 27 - 1,126 – 11 – 25 – 54 – 21 – 0
    • Region 4 – Elevated - 8 of 8 - 14.2% – 24 – 686 – 41 – 41 – 23 – 83 – 4
    • Region 5 – Elevated - 5 of 6 - 11.8% – 28 - 1,034 – 26 – 87 – 45 – 21 – 0
    • Region 6 – Elevated - 5 of 5 - 13.1% – 27 – 230 – 0 – 12 – 23 – 11 – 1
    • Region 7 – Elevated - 4 of 4 - 12.5% – 10 – 384 – 23 – 30 – 29 – 3 – 1
    • Region 8 – Elevated - 6 of 6 - 16.0% – 34 – 970 – 9 – 21 – 25 – 0 – 0
    • Region 9 – Elevated - 5 of 5 - 14.4% – 79 - 2,818 – 83 – 24 – 28 – 17 – 2
    • Region 10 – Elevated - 4 of 4 - 27.7% – 7 - 1,105 – 16 – 8 – 1 – 14 – 0

___

{*} HHS regions (Region 1 CT, ME, MA, NH, RI, VT; Region 2: NJ, NY, Puerto Rico, US Virgin Islands; Region 3: DE, DC, MD, PA, VA, WV; Region 4: AL, FL, GA, KY, MS, NC, SC, TN; Region 5: IL, IN, MI, MN, OH, WI; Region 6: AR, LA, NM, OK, TX; Region 7: IA, KS, MO, NE; Region 8: CO, MT, ND, SD, UT, WY; Region 9: AZ, CA, Guam, HI, NV; and Region 10: AK, ID, OR, WA).

{†} Elevated means the % of visits for ILI is at or above the national or region-specific baseline

{§} Includes all 50 states, the District of Columbia, Guam, Puerto Rico, and U.S. Virgin Islands

{‡} National data are for current week; regional data are for the most recent three weeks

 

U.S. Virologic Surveillance

WHO and NREVSS collaborating laboratories, which include both public health and clinical laboratories located in all 50 states, Puerto Rico, and the District of Columbia, report to CDC the total number of respiratory specimens tested for influenza and the number positive for influenza by virus type. In addition, public health laboratories also report the influenza A subtype (H1 or H3) and influenza B lineage information for the viruses they test and the age or age group of the persons from whom the specimens were collected.

Additional data are available at http://gis.cdc.gov/grasp/fluview/fluportaldashboard.html and http://gis.cdc.gov/grasp/fluview/flu_by_age_virus.html.

___

The results of tests performed by clinical laboratories during the current week are summarized below.

[Week 3 - Data Cumulative since October 2, 2016 (Week 40)]

  • No. of specimens tested - 26,135 - 325,167
    • No. of positive specimens (%) - 4,813 (18.4%) - 25,628 (7.9%)
      • Positive specimens by type:
        • Influenza A - 4,306 (89.5%) - 22,291 (87.0%)
        • Influenza B - 507 (10.5%) - 3,337 (13.0%)

___

(…)

View National and Regional Level Graphs and Data

____

The results of tests performed by public health laboratories, as well as the age group distribution of influenza positive tests, during the current week are summarized below.

[Week 3 - Data Cumulative since October 2, 2016 (Week 40)]

  • No. of specimens tested - 2,096 - 29,277
    • No. of positive specimens* - 1,150 - 10,529
      • Positive specimens by type/subtype:
        • Influenza A - 1,072 (93.2%) - 9,807 (93.1%)
          • A(H1N1)pmd09 - 18 (1.7%) - 258 (2.6%)
          • H3 - 980 (91.4%) - 9,329 (95.1%)
          • Subtyping not performed - 74 (6.9%) - 220 (2.2%)
        • Influenza B - 78 (6.8%) - 722 (6.9%)
          • Yamagata lineage - 35 (44.9%) - 249 (34.5%)
          • Victoria lineage - 20 (25.6%) - 271 (37.5%)
          • Lineage not performed - 23 (29.5%) - 202 (28.0%)

___

{*} The percent of specimens testing positive for influenza is not reported because public health laboratories often receive samples that have already tested positive for influenza at a clinical laboratory and therefore percent positive would not be a valid indicator of influenza activity. Additional information is available at http://www.cdc.gov/flu/weekly/overview.htm.

(…)

 

Antigenic Characterization

CDC has antigenically characterized 298 influenza viruses [37 influenza A (H1N1)pdm09, 201 influenza A (H3N2), and 60 influenza B viruses] collected by U.S. laboratories since October 1, 2016.

    • Influenza A Virus [238]
      • A (H1N1)pdm09 [37]:
        • All 37 (100%) influenza A (H1N1)pdm09 viruses were antigenically characterized using ferret post-infection antisera as A/California/7/2009-like, the influenza A (H1N1) component of the 2016-2017 Northern Hemisphere vaccine.
      • A (H3N2) [201]:
        • 192 of 201 (95.5%) influenza A (H3N2) viruses were antigenically characterized as A/Hong Kong/4801/2014-like, a virus that belongs in genetic group 3C.2a and is the influenza A (H3N2) component of the 2016-2017 Northern Hemisphere vaccine, by HI testing or neutralization testing.
        • Among the viruses which reacted poorly with ferret antisera raised against A/Hong Kong/4801/2014-like viruses, 6 out of 9 (66.7%) are more closely related to A/Switzerland/9715293/2013, a virus belonging to genetic group 3C.3a.
  • Influenza B Virus [60]
    • Victoria Lineage [32]:
      • 29 of 32 (90.6%) B/Victoria-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Brisbane/60/2008-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere trivalent and quadrivalent influenza vaccines.
    • Yamagata Lineage [28]:
      • All 28 (100%) B/Yamagata-lineage viruses were antigenically characterized using ferret post-infection antisera as B/Phuket/3073/2013-like, which is included as an influenza B component of the 2016-2017 Northern Hemisphere quadrivalent influenza vaccines.

 

Antiviral Resistance

Testing of influenza A (H1N1)pdm09, influenza A (H3N2), and influenza B virus isolates for resistance to neuraminidase inhibitors (oseltamivir, zanamivir, and peramivir) is performed at CDC using a functional assay. Additional influenza A (H1N1)pdm09 and influenza A (H3N2) clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. The data summarized below combine the results of both testing methods. These samples are routinely obtained for surveillance purposes rather than for diagnostic testing of patients suspected to be infected with antiviral-resistant virus.

High levels of resistance to the adamantanes (amantadine and rimantadine) persist among influenza A (H1N1)pdm09 and influenza A (H3N2) viruses (the adamantanes are not effective against influenza B viruses). Therefore, data from adamantane resistance testing are not presented below.

___

Neuraminidase Inhibitor Resistance Testing Results on Samples Collected Since October 1, 2016

[Oseltamivir: Virus Samples tested (n) - Resistant Viruses, Number (%) – Zanamivir: Virus Samples tested (n) - Resistant Viruses, Number (%) – Peramivir: Virus Samples tested (n) - Resistant Viruses, Number (%)]

  • A(H1N1pdm09) - 66 - 0 (0.0) – 66 - 0 (0.0) – 66 - 0 (0.0)
  • Influenza A (H3N2) – 488 - 0 (0.0) – 488 0 (0.0) – 379 - 0 (0.0)
  • Influenza B – 126 - 0  (0.0) – 126 - 0 (0.0) – 126 - 0 (0.0)

___

The majority of recently circulating influenza viruses are susceptible to the neuraminidase inhibitor antiviral medications, oseltamivir, zanamivir, and peramivir; however, rare sporadic instances of oseltamivir-resistant and peramivir-resistant influenza A (H1N1)pdm09 viruses and oseltamivir-resistant influenza A (H3N2) viruses have been detected worldwide. Antiviral treatment as early as possible is recommended for patients with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for serious influenza-related complications.

Additional information on recommendations for treatment and chemoprophylaxis of influenza virus infection with antiviral agents is available at http://www.cdc.gov/flu/antivirals/index.htm.

(…)

-

Keywords: US CDC; USA; Updates; Seasonal Influenza.

------