1 Houston Health Department 8000 North Stadium Drive, Houston, TX 77054 (832) 393-5169 HOUSTONHEALTH.ORG
Houston/ Harris County: Texas: CDC:
Increased
Highlights
• The Houston Health Department (HHD) conducts seasonal influenza surveillance
from October (week 40) to May (week 22). In week 9, the percentage of reported
influenza-like illnesses (ILI) detected in emergency centers in Houston/Harris
County was 1.92% which increased from 1.66% reported in the previous week.
The flu vaccine is recommended for the entire season.
Influenza Like Illness (ILI)
• The percentage of Athena ILI reports increased to 0.26% in week 9 compared to the previous week.
Virology
• HHD receives electronic lab reports from clinical labs. During week 9, the volume of flu tests received remained comparable to the previous week. Flu A activity
accounts for 98% of the cumulative flu positives this season.
Influenza Surveillance Report
Division of Disease Prevention and Control Public Health Informatics
CDC MMWR Week 09: February 24, 2019 to March 2, 2019
Influenza Activity by County, State, and National Levels
2 Houston Health Department 8000 North Stadium Drive, Houston, TX 77054 (832) 393-5169 HOUSTONHEALTH.ORG
During week 9, 1.92% of emergency center (EC) visits were due to influenza-like illness (ILI)
complaints. Of the 2384 patients presenting with ILI, the age group that recorded the most EC visits
was the 05 to 17 years old (35%). Females accounted for 54% of patients presenting with ILI.
1.92%
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
3.00%
20
18
-21
20
18
-22
20
18
-23
20
18
-24
20
18
-25
20
18
-26
20
18
-27
20
18
-28
20
18
-29
20
18
-30
20
18
-31
20
18
-32
20
18
-33
20
18
-34
20
18
-35
20
18
-36
20
18
-37
20
18
-38
20
18
-39
20
18
-40
20
18
-41
20
18
-42
20
18
-43
20
18
-44
20
18
-45
20
18
-46
20
18
-47
20
18
-48
20
18
-49
20
18
-50
20
18
-51
20
18
-52
20
19
-01
20
19
-02
20
19
-03
20
19
-04
20
19
-05
20
19
-06
20
19
-07
20
19
-08
20
19
-09
ILI P
erce
nt
(%)
CDC MMWR Week
Percent
28%
35%
23%
8%
6%
Age group
00-04 years
05-17 years
18-44 years
45-64 years
65+ years
54%
46%
Gender
Female
Male
Syndromic Surveillance: ILI activity trend in 2018-2019
Syndromic Surveillance: 2018-2019 Influenza Season Age and Gender Distribution
NOTE: ILI activity is assessed using information provided by the Southeast Texas Syndromic Surveillance System and includes data from 65
hospitals and 17 school-based clinics. Influenza-like illness (ILI) is defined as the mention of fever AND cough, OR fever AND sore throat, OR
flu in the patient’s Emergency Department (ED) chief complaint. These data do not represent laboratory confirmed cases of influenza nor do
they represent all ED visits in Houston/Harris County.
3 Houston Health Department 8000 North Stadium Drive, Houston, TX 77054 (832) 393-5169 HOUSTONHEALTH.ORG
During week 9, the ZIP codes with the highest percent of ED visits (3.38 or greater) were:
77071, 77081, 77036, 77336, 77587, 77571, 77032, 77502, 77598 and 77058
Syndromic Surveillance: Geographic Distribution Map of ILI
NOTE: Houston/Harris County ILI report distribution map was created using data provided by the Southeast Texas
Syndromic Surveillance System and includes data from 65 hospitals and 17 school-based clinics. This map reflects the
number of ILI cases from each residential zip code during the current week of reporting. Influenza-like illness (ILI) is
defined as the mention of fever AND cough, OR fever AND sore throat, OR flu in the patient’s ED chief complaint.
These data do not represent laboratory confirmed cases of influenza nor do they represent all ED visits in
Houston/Harris County.
4 Houston Health Department 8000 North Stadium Drive, Houston, TX 77054 (832) 393-5169 HOUSTONHEALTH.ORG
In week 9, ILI accounted for 0.26% of outpatient visits in the Athena network. The total count of ILI
visits reported within the network was 25.
0.26%
0.00%
0.10%
0.20%
0.30%
0.40%
0.50%
0.60%
ILI P
erce
nt
Week Start Date
0
5
10
15
20
25
30
35
40
45
50
46 47 48 49 50 51 52 1 2 3 4 5 6 7 8 9
ILI C
ou
nt
Week
Age: 65 or older
Age: 50 - 64
Age: 18 - 49
Age: 5 - 17
Age: 0 - 4
Athena: ILI percentage per week from 2017-19
Athena: ILI per week by age group
5 Houston Health Department 8000 North Stadium Drive, Houston, TX 77054 (832) 393-5169 HOUSTONHEALTH.ORG
NOTE: Data on student ILI and influenza cases is collected from 306 schools within Houston Independent school district.1 School will be counted more than once if more than one case from the same school is reported during the same reporting period.
Flu near You (FNY) is a participatory surveillance tool that compliments traditional disease surveillance. The count
of Flu Near You (flunearyou.org) users reporting ILI in the week of 02/24/2019 increased from 16 to 28 in the
previous week. See the last page for information on how to participate.
Table 1: ILI and Influenza Cases by Type and School Type1 per Month
School surveillance for ILI began in October for the current flu season. In February, a total of 726 cases were
reported. The highest number of cases (531) were among elementary school students.
28
0
20
40
60
80
100
120
140
160
180
200
1/2
/20
17
1/2
3/2
01
7
2/1
3/2
01
7
3/6
/20
17
3/2
7/2
01
7
4/1
7/2
01
7
5/8
/20
17
5/2
9/2
01
7
6/1
9/2
01
7
7/1
0/2
01
7
7/3
1/2
01
7
8/2
1/2
01
7
9/1
1/2
01
7
10
/2/2
01
7
10
/23
/20
17
11
/13
/20
17
12
/4/2
01
7
12
/25
/20
17
1/1
5/2
01
8
2/5
/20
18
2/2
6/2
01
8
3/1
9/2
01
8
4/9
/20
18
4/3
0/2
01
8
5/2
1/2
01
8
6/1
1/2
01
8
7/2
/20
18
7/2
3/2
01
8
8/1
3/2
01
8
9/3
/20
18
9/2
4/2
01
8
10
/15
/20
18
11
/5/2
01
8
11
/26
/20
18
12
/17
/20
18
1/7
/20
19
1/2
8/2
01
9
2/1
8/2
01
9
ILI C
ou
nt
Week Start Date
ILI
Month Total
Cases
Lab
Confirmed Flu A Flu B A+B Unclassified
Elementary
Schools
Middle
Schools
High
Schools
Multi-
level
Schools # %
Oct 66 15 23% 2 4 0 8 54 2 4 6 Nov 64 11 17% 5 1 1 52 55 0 4 5 Dec
Dec 56 10 18% 12 0 0 0 51 3 1 1
Sum 1595 444 28% 115 60 1 317 723 64 55 116
56 10 18% 12 0 0 0 51 3 1 1 Jan 129 33 26% 26 0 1 94 102 15 9 3 Feb 726 283 39% 54 19 8 197 531 142 25 28
Sum 1041 352 34% 99 24 10 351 793 162 43 43
School Surveillance October 2018 - February 2019
Flu Near You: ILI per week
6 Houston Health Department 8000 North Stadium Drive, Houston, TX 77054 (832) 393-5169 HOUSTONHEALTH.ORG
HHD receives electronic lab reports from clinical laboratories. In Week 9 of 2019, there were 148
laboratory confirmed influenza cases.
HHD received 4 nonelectronic lab reports of flu-positive results from clinical laboratories during
this reporting period. December accounts for the highest counts (n=5) of Flu activity in 2018.
0
100
200
300
400
500
600
700
20
18
_1
20
18
_2
20
18
_3
20
18
_4
20
18
_5
20
18
_6
20
18
_7
20
18
_8
20
18
_9
20
18
_1
02
01
8_
11
20
18
_1
22
01
8_
13
20
18
_1
42
01
8_
15
20
18
_1
62
01
8_
17
20
18
_1
82
01
8_
19
20
18
_2
02
01
8_
21
20
18
_2
22
01
8_
23
20
18
_2
42
01
8_
25
20
18
_2
62
01
8_
27
20
18
_2
82
01
8_
29
20
18
_3
02
01
8_
31
20
18
_3
22
01
8_
33
20
18
_3
42
01
8_
35
20
18
_3
62
01
8_
37
20
18
_3
82
01
8_
39
20
18
_4
02
01
8_
41
20
18
_4
22
01
8_
43
20
18
_4
42
01
8_
45
20
18
_4
62
01
8_
47
20
18
_4
82
01
8_
49
20
18
_5
02
01
8_
51
20
18
_5
22
01
9_
01
20
19
_0
22
01
9_
03
20
19
_0
42
01
9_
05
20
19
_0
62
01
9_
07
20
19
_0
82
01
9_
09
Number of flu positives reported via Electronic Lab Reports per Week in 2018 and 2019
Flu B
Flu A & B
Flu A
Nu
mb
er o
f p
osi
tive
case
s
CDC Week (Year_Week)
0
1
2
3
4
5
6
Number of flu positives reported via Non-electronic Lab Reports per Month in 2018 Flu B
Flu A + B
Flu A
Nu
mb
er o
f p
osi
tive
Month
Passive Viral Surveillance, Electronic lab reports
Passive Viral Surveillance, Nonelectronic lab reports
7 Houston Health Department 8000 North Stadium Drive, Houston, TX 77054 (832) 393-5169 HOUSTONHEALTH.ORG
The Houston Influenza Surveillance Weekly Report is available on the
Houston Health Department web site at:
https://www.houstontx.gov/health/Epidemiology
Flu Near You is a participatory surveillance (crowd sourcing) tool which complements traditional disease surveillance activities. Registered users can obtain real-time information on flu activity and influenza vaccines in the Greater Houston Metropolitan Area. Flu Near You features include: MAP CASES
Report symptoms Find vaccines
Map flu cases in the Greater Houston Metropolitan area
Get flu news
Share on social media This season HHD invites you to register for Flu Near You at https://flunearyou.org
NOTE: Influenza-like Illness (ILI) is defined as fever (temperature ≥ 100°F) plus a cough OR a sore throat, in the absence of a known cause other than influenza. Houston ILI baselines were determined using the same method as the Centers for Disease Control and Prevention Regional ILI
baseline. Data was obtained or accessed through the Southeast Texas Syndromic Surveillance System. However, any conclusions drawn from use of this data do not represent the official views of any consortium member jurisdiction. Additional information regarding Houston, Texas and national ILI activity can be accessed at: http://www.houstontx.gov/health/ http://www.dshs.texas.gov/IDCU/disease/influenza/surveillance/2019.aspx http://www.cdc.gov/flu/weekly/ http://www.who.int/csr/don/en/
*Below baseline means the % of visits for ILI is below the region-specific baseline of 4.0%. https://www.cdc.gov/flu/weekly/overview.htm The numbers for pediatric flu-related deaths may change as information becomes available.
** Flu-related deaths in adults are not required to be reported to health department. Numbers for flu-related deaths may change as information becomes available.
Houston Health Department
Division of Disease Prevention and Control
Public Health Informatics
8000 N. Stadium Dr., 4th Floor Houston, TX
77054
Main Phone Number: (832) 393-5080
Disease Reporting Fax Number: (832) 393-5232
24-Hour Disease Reporting Number: (832) 393-5080