Week 39 ending October 1, 2016

Dallas County Health and Human Services

Arbovirus Surveillance Report

†One mosquito trap containing only Aedes albopictus was positive for WNV, and is not included in VI calculations.

*Data for most recent 2 weeks are preliminary, and reflect results reported as of 10:30 a.m. October 3, 2016.

a. All traps deployed in municipalities submitting data to DCHHS since Week 13. Includes traps without mosquitoes, malfunctioning traps and traps with pending results

b. Excludes traps without female Culex quinquefasciatus identified. Maximum of 50 female Culex quinquefasciatus per pool; more than 1 pool may be tested per trap

c. PHL = Public health laboratory (DSHS, DCHHS) testing performed by viral culture or CDC RT-PCR protocol; IL = Testing from independent labs by alternate methods

d. Average abundance of female Culex quinquefasciatus mosquitoes per trap night/week (excludes non-working traps)

e. WNV Infection rates calculated using a Maximum Likelihood Estimation (MLE). Biggerstaff BJ. PooledInfRate, version 4.0; Microsoft Excel Add-In; CDC 2007

f. The Vector Index (VI) reflects the MLE adjusted for Culex quinquefasciatus abundance. VI= ∑ �̅�𝒊�̂�𝒊𝒊=𝒔𝒑𝒆𝒄𝒊𝒆𝒔 , where N is the average number of Culex quinquefasciatus

mosquitoes collected per trap night and �̂� is the estimated infection rate

g. Human cases by week of report to health department. WNND = West Nile Neuroinvasive Disease; WNF = West Nile Fever

h. All Biogents (BG) Sentinel traps deployed in municipalities submitting data to DCHHS since Week 15. Includes traps without mosquitoes, malfunctioning traps

i. Average abundance of Aedes albopictus and Aedes aegypti mosquitoes per night/trap in BG-Traps (excludes non-working traps)

j. Human CHKV cases by week of report to health department (AT : Autochthonous case; I : imported)

k. Human Dengue cases by week of report to the health department

l. Confirmed human Zika cases by week of report to health department (Excludes any pregnant cases)

m. Possible Zika Virus Infection Among Pregnant Women — United States and Territories, May 2016, http://www.cdc.gov/mmwr/volumes/65/wr/mm6520e1.htm/

Week Ending 8/20 8/27 9/3 9/10 9/17 9/24 10/1 YTD

MMWR Week 33 34 35 36 37 38* 39*

Total Traps Placed in Dallas County a 240 249 246 224 248 240 238 5,604

Number of Positive Mosquito Traps (PHL; IL) c 35; 2 22; 5 24; 3 30; 7 23; 4 18; 2 14; 3 569†; 63

Number of Pools Tested (PHL; IL) b,c 194; 30 204; 29 221; 29 207; 40 238; 37 182; 30 142; 40 4,968; 644

Number of Trap Results Currently Pending 0 0 0 0 4 29 38

Average Number of Cx. quinquefasciatus per Trap d 20.1 16.5 34.1 45.9 66.3 37.8 30.6 35.9

Total Number of Cx. quinquefasciatus Trapped and Tested 4,459 3,723 6,378 7,595 8,834 5,958 4,814 147,519

Number of Positive Mosquito Pools (PHL; IL) c 35; 2 22; 5 24; 3 31; 7 27; 4 19; 2 14; 3 606; 63

WNV Infection Rate per 1,000 Cx. quinquefasciatus e 9.37 7.85 4.57 5.61 3.81 3.78 3.79

Weekly Vector Index (VI) f 0.19 0.13 0.16 0.26 0.25 0.14 0.12

Presumptive WNV Viremic Blood Donors 0 0 0 2 0 0 0 2

WNV Human Cases (WNND; WNF) g 4; 4 6; 0 3; 1 1; 4 0; 0 2; 1 0; 1 27; 19

Week Ending 8/20 8/27 9/3 9/10 9/17 9/24 10/1 YTD

MMWR Week 33 34 35 36 37 38* 39*

Total Biogents Sentinel-Traps Placed in Dallas County h 41 46 37 32 36 40 36 793

Average Number of Aedes per Trap i 2.6 15.7 16.1 8.6 5.9 14.0 7.0 7.3

Chikungunya Human Cases (Confirmed & Probable) j 0 0 0 0 0 0 0 2

Dengue Human Cases (Confirmed & Probable) k 0 0 0 1 0 0 0 3

Zika Human Cases (Confirmed Only) l 4 0 2 1 0 0 2 35

Pregnant Women with Possible Zika Infection m 2 4 0 0 1 0 0 19

Table 1. Mosquito Laboratory and Human Case Surveillance Data for WNV, Dallas County

In week 38, 20 mosquito traps tested positive for WNV. In week 39 to date, 17 mosquito traps have tested positive for WNV in zip codes: 75004, 75050, 75051, 75063, 75080, 75082, 75104, 75115, 75137, 75146, 75149, 75150, 75182.

Forty six human WNV cases, including 27 patients with neuroinvasive disease have been reported.

To date, 889 Dallas County residents have been tested for Zika infection.

Thirty five travel-associated confirmed cases of Zika infection have been identified in Dallas. An additional 19 pregnant women with laboratory criteria for possible Zika infection have been reported to CDC for US Zika Pregnancy Registry surveillance, 4 of whom had symptoms.m

Aedes aegypti and Aedes albopictus continue to circulate in the area.

Table 2. Mosquito Laboratory and Human Case Surveillance Data for Chikungunya, Dengue and Zika Virus, Dallas County

PHONE EMAIL WEB

DCHHS Epidemiology (214) 819-2004 Epidemiology@dallascounty.org www.dallascounty.org/hhs

*Data for most recent 2 weeks are preliminary

Week Ending 8/20 8/27 9/3 9/10 9/17 9/24 10/1 YTD

MMWR Week 33 34 35 36 37 38* 39*

# Human

WNV Cases Range Total #

of Traps/Week1 # WNV+

Traps # WNV+

Traps # WNV+

Traps # WNV+

Traps # WNV+

Traps # WNV+

Traps # WNV+

Traps

Addison 1 2 2 0 1 0 0 0 Pending 10

Balch Springs 0 3 0 0 0 1 0 1 0 12

Carrollton 1 7 3 0 1 3 3 0 Pending 37

Cedar Hill 0 5 1 1 0 1 0 0 1 8

Cockrell Hill 0 1 0 0 1 0 0 0 0 3

Coppell 4 6 1 2 1 3 3 1 Pending 31

Dallas 27 68 - 85 10 5 2 2 3 4 0 118

DeSoto 1 6 3 0 3 1 1 2 3 27

Duncanville 0 5 1 1 1 1 1 2 1 17

Farmers Branch 0 4 1 1 1 1 0 0 Pending 13

Garland 4 20 - 27 4 3 3 5 1 0 1 44

Glenn Heights 0 2 0 0 0 1 0 0 0 1

Grand Prairie 1 24 - 30 2 5 3 7 4 2 2 56

Highland Park 0 2 - 6 0 1 0 0 1 1 0 9

Hutchins 0 1 0 0 0 0 0 0 0 4

Irving 5 13 - 15 4 2 4 0 4 2 1 70

Lancaster 0 4 0 0 1 1 1 1 2 13

Mesquite 2 17 - 19 4 3 0 4 2 1 3 90

Richardson 0 8 - 12 0 1 3 0 1 1 2 22

Rowlett 0 6 - 7 1 2 0 2 0 1 0 21

Sachse 0 3 0 0 0 2 1 1 0 11

Seagoville 0 2 0 0 1 2 0 0 0 4

Sunnyvale 0 2 0 0 0 0 0 0 1 3

Unincorporated County 0 1 0 0 1 0 0 0 0 1

University Park 0 2 - 4 0 0 0 0 0 0 0 4

Wilmer 0 1 0 0 0 0 1 0 0 3

Total 46 37 27 27 37 27 20 17 632

Positive Traps Negative Traps Pending Traps

Table 3. WNV Positive Gravid Mosquito Traps by City, Dallas County*

Figure 1: All WNV Negative and Positive Mosquito Traps Collected During 2016: Weeks 13-39* (N=5,604)

*Data for most recent 2 weeks are preliminary, and reflect results reported as of 10:30 a.m. October 3, 2016. “Pending” indicates that no results for any traps have yet been received. 1Range of

numbers of traps placed weekly, in weeks 25-38.

Figure 2: Cumulative WNV Positive Mosquito Traps Collected: Weeks 13-39* (N=632)

PHONE EMAIL WEB

DCHHS Epidemiology (214) 819-2004 Epidemiology@dallascounty.org www.dallascounty.org/hhs

*Data for most recent 2 weeks are preliminary

< 100 Mosquitoes/Trap 100 - 499 Mosquitoes/Trap

500 - 1000 Mosquitoes/Trap >1000 Mosquitoes/Trap

Positive Traps

** Vector Index of 0.50 is the historical threshold associated with larger local epidemics of WNV illnesses in humans. Note: Most recent 1-2 weeks data are preliminary and subject to change following receipt of data still pending.

Figure 3: WNV Positive Mosquito Traps Collected During

2016: Weeks 38 and 39* (N=37)

Figure 4: Trap Counts of Female Cx. quinquefasciatus

from 2016 Season: Weeks 13-39*

Figure 5: Average Numbers of Female Cx. quinquefasciatus per Trap-night and WNV Vector Index by Week:

2012 Season and 2016 Season (through Week 39*)

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*Figure 4 only shows traps for which results were available; malfunctioning traps were excluded. Almost all traps are at fixed sites. Note: Most recent 1-2 weeks data are preliminary and subject to change following receipt of data still pending.

PHONE EMAIL WEB

DCHHS Epidemiology (214) 819-2004 Epidemiology@dallascounty.org www.dallascounty.org/hhs

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Figure 6: WNV Vector Index by Week: 2012 - 2016 Seasons

Figure 7: Average Numbers of Female Cx. quinquefasciatus per Trap-night by Week: 2012 - 2016 Seasons

The Vector Index (VI) reflects the MLE adjusted for Culex

quinquefasciatus abundance. VI= ∑ 𝑁𝑖�̂�𝑖𝑖=𝑠𝑝𝑒𝑐𝑖𝑒𝑠 , where N

is the average number of Culex quinquefasciatus mosquitoes

collected per trap night and �̂� is the estimated infection rate

PHONE EMAIL WEB

DCHHS Epidemiology (214) 819-2004 Epidemiology@dallascounty.org www.dallascounty.org/hhs

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Human WNV Cases (N=398)

Viremic Blood Donors by Date of Report (N=17)

Vector Index

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Figure 9: WNV Vector Index, Viremic Blood Donors, and Human WNV Cases by Week of Report:

2012 Season

*

Figure 8: MLE (WNV Infection Rate per 1,000 Cx. quinquefasciatus) by Week: 2012 - 2016 Seasons

PHONE EMAIL WEB

DCHHS Epidemiology (214) 819-2004 Epidemiology@dallascounty.org www.dallascounty.org/hhs

Country/Territories # Human Zika Cases (%)

Mexico 8 (22.9)

Guatemala 5 (14.3)

Jamaica 4 (11.4)

Puerto Rico 4 (11.4)

Honduras 3 (8.6)

El Salvador 2 (5.7)

Dominican Republic 2 (5.7)

Nicaragua 2 (5.7)

Virgin Islands 1 (2.9)

Colombia 1 (2.9)

Venezuela 1 (2.9)

Belize 1 (2.9)

Trinidad 1 (2.9)

Total 35

Figure 12: Average Numbers of Aedes albopictus per Trap-night:

2015 and 2016 Seasons*

Figure 10: BG-Sentinel Trap Counts of Female Aedes aegypti and Aedes albopictus During 2016: Weeks 15 through 39

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0 Mosquitoes/Trap <10 Mosquitoes/Trap

10-30 Mosquitoes/Trap >30 Mosquitoes/Trap

Figure 11: Average Numbers of Aedes aegypti per Trap-night:

2015 and 2016 Seasons*

*Aedes BG-Sentinel trapping began Week 22 in 2015

Table 4: Travel-Associated Zika Infections by Country/Territories: 2016 Season, Dallas County

PHONE EMAIL WEB

DCHHS Epidemiology (214) 819-2004 Epidemiology@dallascounty.org www.dallascounty.org/hhs

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We are grateful for the partnership of the following contributors to our county-wide Arboviral Surveillance Report: Mosquito Trapping and Data from Environmental Health Services Divisions of the Following Cities:

Addison Balch Springs Carrollton Cedar Hill Cockrell Hill Coppell Dallas DeSoto Duncanville Farmers Branch Garland Glenn Heights Grand Prairie

Data alert Data warning Data normal

Mosquito Speciation and Laboratory Testing:

DCHHS Environmental Health Services: Mosquito Lab

DCHHS LRN Laboratory

DSHS Laboratory Services, Arbovirus-Entomology Team

Municipal Mosquito

Human Case Reports and Investigations:

Area Acute Care Hospitals and Healthcare Providers

Dallas County Medical Examiner’s Office

City of Dallas Vital Statistics Unit

Carter Blood Care

American Red Cross

DCHHS Acute Communicable Disease Epidemiology Division

Zika Pregnancy Registry Team

Arboviral Case Investigation and Clinical Inquiries Team

For inquiries related to this Arboviral Surveillance Report, please

contact: Kyoo Shim, MPH

Figure 13: Syndromic Surveillance of Emergency Department Visits for Chief Complaints of Rash, Dallas County:

January 1, 2016 – October 1, 2016

,

Data source: 18 emergency departments in Dallas County hospitals participating in the Electronic Surveillance System for the Early Notification Of Community-based Epidemics (ESSENCE) voluntarily reporting the numbers of persons presenting with self-reported chief complaints of rash.

Acknowledgements:

Highland Park Hutchins Irving Lancaster Mesquite Richardson Rowlett Sachse Seagoville Sunnyvale University Park Wilmer

Mosquito Trapping and Data From:

DCHHS Environmental Health Services: Vector Control Division

Municipal Mosquito

Vector Disease Control International