Weekly Report 2017 Week 4 (January 22 – January 28, 2017) through 2018 Week 4 ( January 21 – January 27, 2018)

Department of Health and Human Services

Office of Analyt ics

Brian Sandoval

Governor

State of Nevada

Richard Whitley, MS

Director

Department of Health and Human Services

Julie Kotchevar, Ph.D

Acting Administrator

Division of Public and Behavioral Health

February, 2018

Edition 1.0

Influenza Weekly Report v 2018 i 4 (January 21 – January 27, 2018)

Page 1 of 5

Data for the graphs and tables on the following pages are provisional and may be updated as additional information becomes available.

Purpose

The purpose of this report is to provide an overview of and statistics for the influenza season in Nevada for the local public health authorities, sentinel

providers and the public.

Sentinel Provider Data: Influenza-Like Illness Network Surveillance (ILINet)

Respiratory specimens are tested for influenza by the World Health Organization (WHO) and National Respiratory and Enteric Virus Surveillance

System (NRVESS) collaborating laboratories by sub-type. During week 4, there were 61,860 specimens collected and tested for influenza, of those

17,024 were positive (27.5%).

Figure 1

Source of Data: CDC: FluView Weekly Report.

The Nevada total includes laboratory tests for all Nevada residents tested by sentinel providers including out of state laboratories. Laboratory data

is obtained from CDC’s ILINet system. During week 4, where there were 87 specimens collected, in which 37 were positive. There is a two-week

delay for laboratory surveillance. Data are subject to change as we receive additional reports.

Figure 2

Source of Data: CDC: ILINet.

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National Influenza Positive Tests by Week53 Week Comparison (2017 WK 4 - 2018 WK 4)

2009H1N1 A(H3) A(Unknown Subtyping) B (Victoria Lineage)

B (Yamagata Lineage) B(Unknown Subtyping) Percent Positive

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Nevada (ILI Providers) Influenza Laboratory Confirmed Positive by Week53 Week Comparison (2017 WK 4 - 2018 WK 4)

2009H1N1 A(H3) A(Subtyping not performed) B (Victoria Lineage)B (Yamagata Lineage) B(Unknown Subtyping) Percent Positive

Influenza Weekly Report v 2018 i 4 (January 21 – January 27, 2018)

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Nevada State Public Health Laboratory (NSPHL) has tested 371 specimens for influenza from sentinel providers, of which there have been 316

positive (85.2%). Southern Nevada Public Health Laboratory (SNPHL) has tested 44 specimens this season of which there have been 4 positive.

Nationally, there have been 629.214 specimens sent to the WHO and NERVSS laboratories of which 126,117 have been positive (20.0%). The

national numbers in Table 1 are reflected in Figure 1. The state of Nevada data in Table 1 is reflected in Figure 2. The Nevada total includes

laboratory test for all Nevada residents tested by sentinel providers, including out of state laboratories.

Table 1

Influenza Specimens Tested State and Nationally through Sentinel Providers

NSPHL

SNPHL All Other

Laboratories

State of Nevada (Week 4)

State of Nevada (Season)

National (Week 4)

National (Season)

# % # % # % # %

Specimens Tested 371 44 785 87 - 1200 - 61,860 629,214

Influenza Positives 316 4 222 37 42.5 542 45.2 17,024 27.5 126,117 20.0

Influenza A: 265 3 197 19 51.4 465 85.8 13,072 76.8 103,551 82.1

A (2009 H1N1) 15 0 0 0 0.0 15 3.2 189 1.4 1,896 1.8

A (H3) 250 3 5 5 26.3 258 55.5 1,017 7.8 18,068 17.4

A (Sub-typing not performed) 0 0 192 14 73.7 192 41.3 11,866 90.8 83,587 80.7

Influenza B: 51 1 25 18 48.6 77 14.2 3,952 23.2 22,566 17.9

B (Victoria Lineage) 1 0 0 0 0.0 1 1.3 13 0.3 228 1.0

B (Yamagata Lineage) 50 0 1 11 61.1 51 66.2 201 5.1 2,292 10.2

B (Sub-typing not performed)

0 1 24 7 38.9 25 32.5 3,738 94.6 20,046 88.8

Source of Data: CDC: FluView Report and CDC: ILINet.

Influenza-like Illness (ILI) Surveillance Network has each sentinel provider report the number of patients seen that meet the ILI case definition

and the total number of patients seen for any reason each week. The “percentage of visits for ILI” is the number of ILI patients divided by the total

number of patients visit per week. Nevada’s percentage of ILI visits for week 4 is 3.6% which is above the state baseline of 1.5%. Region 9 ILI

percentage for week 4 is 3.8% which is the above the region baseline of 2.4%. Region 9 includes the following states/territory: Arizona,

California, Guam, Hawaii, and Nevada. The national ILI percentage for week 4 is 7.1% which is above the national baseline 2.2%.

Figure 3

Source of Data: CDC: Flu View Report and CDC: ILINet.

During week 4, 3.6% of visits to sentinel providers were due to ILI; this is greater than the 2016-2017 influenza season (1.5%). There were

11,723 patients seen by sentinel providers during week 4, of which 427 patients presented with ILI; week 4 of 2017, there were 308 patients

seen with ILI (19,948 total patients seen). Data availability depends on sentinel provider reporting.

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Percentage of Visits for ILI Reported to Outpatient ILI Surveillance Network,Comparison Between National, Regional, and State,

53 Week Comparison (2017 WK 4 - 2018 WK 4)

Nevada Region 9 National

Nevada Baseline Region 9 Baseline National Baseline

Influenza Weekly Report v 2018 i 4 (January 21 – January 27, 2018)

Page 3 of 5

Figure 4

Source of Data: CDC: ILINet.

Influenza-like Illness is reported by age groups. During week 4, patients ages 5-24 were the greatest number of patients seen with ILI, at 125 patients

seen. The rate for week 4 is 14.2 per 100,000 population. The rate is calculated by the number of patients presented with ILI, divided by the state

population, multiplied by 100,000. The estimated state population for 2018 is 2,969,849.

Figure 5

Source of Data: CDC: ILINet.

Influenza Positive Surveillance (NBS and NETSS)

Positive cases of influenza are reported to the state health authority for surveillance purposes. Table 2 and Figure 6 reflect all positive influenza cases

reported to the state. Types of influenza testing include commercial rapid diagnostic test (rapid), viral culture, fluorescent antibody, enzyme

immunoassay, RT-PCR (PCR), and Immunohistochemistry. The two most common test types in Nevada are Rapid and PCR tests. During week 4, there

were 784 influenza cases reported to the state, 365 influenza A, 385 influenza B and 34 unknown subtyping.

Table 2

Reporting Jurisdiction

Reported Influenza Cases by County Jurisdiction and Influenza Type

Current Week (Week 4) Cumulative Influenza Season

A B Unknown Total A B Unknown Total

Carson City Health and Human Services 65 55 6 126 1046 265 34 1,345

Rural Community Health Services 42 115 2 159 800 256 15 1,071

Southern Nevada Health District 180 118 7 305 5993 783 202 6,978

Washoe County Health District 78 97 19 194 2791 706 289 3,786

State of Nevada 365 385 34 784 10,630 2,010 540 13,180

Source: to Office of Analytics: NBS and SNHD: NETSS.

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Nevada Percentage of Visits for Influenza-like Illness, Weekly Summary53 Week Comparison (2013-2018)

2017 WK 04 - 2018 WK 04 2016 WK 04 - 2017 WK 04 2015 WK 04 - 2016 WK 042014 WK 04 - 2015 WK 04 2013 WK 04 - 2014 WK 04 Baseline

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ILINet: Influenza-like Illness by Age Group and MMWR Week and Incidence Rate 53 Week Comparison (2017 WK 4 - 2018 WK 4)

0-4 5-24 25-49 50-64 65+ Rate

Influenza Weekly Report v 2018 i 4 (January 21 – January 27, 2018)

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Figure 6

Source of Data: to Office of Analytics: NBS and SNHD: NETSS.

Hospitalizations

There were 41 hospitalizations associated with influenza reported to the state health authority for week 4.

Table 3

Influenza Hospitalizations

Reporting Jurisdiction Current Week (Week 4) Cumulative Influenza Season # % # %

Carson City Health and Human Services 5 12.2% 116 9.5% Rural Community Health Services 0 0.0% 35 2.9%

Southern Nevada Health District 20 48.8% 664 54.2% Washoe County Health District 16 39.0% 410 33.5%

State of Nevada 41 100.0% 1,225 100.0% Source: Reported to Office of Analytics from each Jurisdiction.

Pneumonia and Influenza (P&I) Mortality Surveillance

The Pneumonia and Influenza (P&I) mortality percentage is all deaths, where Pneumonia or Influenza is listed as the underlying or contributing cause

of death, divided by the total deaths in Nevada for each week. As of February 6th, there were 50 P&I deaths and 405 total deaths for week 4 in Nevada.

Please note that the CDC does not have updated P&I counts for week 3 or week 4.

Figure 7

Source: OVR: WEVRRS and CDC: FluView.

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Weekly Reported Influenza by Subtype as Compared with Respiratory Syncytial Virus Infections (RSV) 53 Week Comparison (2017 WK 4- 2018 WK 4)

Influenza A Influenza B Unknown Influenza Subtyping RSV

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Pneumonia and Influenza (P&I) Mortality by Week,NCHS Mortality Data Compared to Nevada

53 Week Comparison (2017 WK 4 - 2018 WK 4)

Nevada National National Epidemic Threshold

Influenza Weekly Report v 2018 i 4 (January 21 – January 27, 2018)

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Technical Notes • Data are subject to changes, additionally, there is a lag in reporting.

• Influenza surveillance procedures vary by jurisdiction.

• Influenza-like illness (ILI): a fever greater than or equal 100℉ with cough and/or sore throat.

• Percent positive: The number of positive influenza laboratory tests divided by the total number of tests performed.

• Incidence rate is per 100,000 population as estimated by the state demographer.

This report contains information from national and state-level data sources. Influenza surveillance data is collected by a various systems,

including:

• Influenza-like Illness Network (ILINet): a sentinel surveillance system in collaboration with the Centers for the Disease Control and

Prevention (CDC) where outpatient providers report ILI information weekly.

• National Electronic Telecommunication System for Surveillance (NETSS): a system whereby data is transmits to CDC. Influenza

data collected through NETSS does not provide influenza sub-typing information.

• National Electronic Disease Surveillance System (NEDSS): a system for collecting data and monitoring disease trends and

outbreaks.

• NEDSS Based System (NBS): an implementation of the NEDSS standards. It provides a secure, accurate, and efficient means of

collecting, transmitting, and analyzing public health data.

Citations

1. CDC. FluView: A Weekly Influenza Surveillance Report. http://www.cdc.gov/flu/weekly/pastreports.htm.

2. Nevada State Demographer’s Office. 2003-2020 ASRHO Estimates and Projections. Division of Public and Behavioral Health edition.

Vintage 2015.

3. Office of Analytics. DHHS. NBS. 2016-2018. Accessed February 2018.

4. Office of Vital Records (OVR). DPBH. Web Enabled Vital Records Registry System (WEVRRS) [unpublished data]. 2017-2018. Accessed

February 2018.

5. Southern Nevada Health District (SNHD). NETSS/Trisano. 2016-2018. Accessed February 2018.

Comments, suggestions, and requests for further information may be addressed to:

NEVADA INFLUENZA SURVEILLANCE PROGRAM

OFFICE OF ANALYTICS

4126 TECHNOLOGY WAY

CARSON CITY, NV 89706

TEL: (775) 684-5997

FAX: (775) 684-5999

Compiled and Written by: Helen See, MPH

Reviewed by: Jennifer Thompson

Melissa Peek-Bullock

Recommended Citation:

Department of Health and Human Services. Office of Analytics. Influenza Weekly Report, 2017 Week 4 (January 22, 2017) through 2018 Week 4

(January 27, 2018), Nevada. February 2018 i 4 edition 1.0.

This publication was supported by Cooperative Agreement Number TP000534-02 from the Centers for

Disease Control and Prevention and/or Assistant Secretary for Preparedness and Response. Its contents

are solely the responsibility of the authors and do not necessarily represent the official views of the

Centers for Disease Control and Prevention and/or Assistant Secretary for Preparedness and Response.