TCPH West Nile Virus (WNV) Activity Report MMWR Week 29 (July 13 - July 19, 2014) Report Date: July 23, 2014 185 mosquito pools submitted during MMWR Week 29; Three pools with collection dates during Week 29 tested positive for WNV – Bedford (2), Colleyville (1); One pool with collection date during Week 30* tested positive for WNV – Euless (1); All pools tested negative for SLEV 1,977 mosquito pools submitted in 2014; All pools have tested negative for SLEV; Eleven pools have tested positive for WNV: - Bedford (5) - Benbrook (1) - Colleyville (4) - Euless (1)* No human WNV cases have been reported to date in Tarrant County for 2014 More information can be found at: Take Control, Stop West Nile Virus * Positive pool collected in week 30 is not included in the table below as it does not fall within the weeks covered in this report Table 1. WNV activity summary, Tarrant County, Weeks 25-29, 2014 Week Jun 15 Jun 21 Jun 22 Jun 28 Jun 29 Jul 5 Jul 6 Jul 12 Jul 13 Jul 19 MMWR Week 25 26 27 28 29 Total traps placed in Tarrant County 188 145 191 183 169 2,212 Average number of female Culex species per trap 21.8 38.2 27.7 95.0 91.6 30.2 Number of mosquito pools tested1 182 104 156 186 185 1,977 1 1 2 3 3 10 0;0 0;0 0;0 0;0 0;0 0;0 0 0 0 0 0 0 0.46 0.47 0.59 0.57 0.53 0.008 0.016 0.016 0.054 0.047 Number of positive mosquito pools 2 Confirmed WNV human cases (WNF; WNND) 3 Presumptive WNV viremic blood donors WNV infection rate per 1,000 Cx. quinquefasciatus 5 Weekly vector index 4 YTD 1 Based on lab testing date 2 Based on mosquito collection date 3 Based on onset of illness date for cases reported to Tarrant County Public Health; WNF=West Nile Fever; WNND = West Nile Neuroinvasive Disease 4 Calculated using a Maximum Likelihood Estimation (MLE). Biggerstaff, Brad J. PooledInfRate, Version 4.0: a Microsoft® Office Excel© Add-In to compute prevalence estimates from pooled samples. Centers for Disease Control and Prevention, Fort Collins, CO, U.S.A., 2009 5 Vector Index is a measure of infectivity accounting for vector species composition, vector species population density, and proportion of vector population infected with WNV Data subject to change due to on-going case investigations, mosquito collection, and testing Data source: Tarrant County Public Health Tarrant County West Nile Virus Update 07/23/14 Figure 1. Average number of female Culex species per trap, Tarrant County, Weeks 14-29, 2014 Average female Culex species 100.0 2013 Average 2014 Average 75.0 50.0 25.0 0.0 14 15 16 17 18 19 Apr 20 21 22 23 May 24 25 26 27 28 Jun 29 Jul Collection date by MMWR week Data source: Tarrant County Public Health Figure 2. Percentage of submitted mosquito pools that tested positive for WNV, Tarrant County, Weeks 14-29, 2012-2014 60.0 2012 2013 2014 50.0 44.4 40.0 47.4 2.0 40.0 1.6 27.3 20.0 0.6 1.0 1.1 1.0 0.6 2013 & 2014 Percent 50.0 2012 Percent 3.0 61.5 0.6 0.0 0.0 14 15 16 17 18 Apr 19 20 May 21 22 23 24 Jun 25 26 27 28 29 Jul Lab testing date by MMWR week Data source: Tarrant County Public Health Page 2 of 3 Tarrant County West Nile Virus Update 07/23/14 Figure 3. Mosquito trap results and human WNV cases, Tarrant County, Week 29, 2014 Map created using the Tarrant County Public Health WNV Interactive Mapping Tool available at https://mapit.tarrantcounty.com/ WNVCoopPublic/# Note: Map does not reflect all positive pools for the week due to data limitations at time of publication. An updated map is available online at https://mapit.tarrantcounty.com/WNVCoopPublic/# State-wide WNV activity reported on July 22, 2014 A total of 446 mosquito pools have tested positive for WNV in the following Texas counties: - Dallas (9) - Harris (363) - Montgomery (67) - Tarrant (7) Five human WNV cases have been reported in the following Texas counties: - Dallas (2 WNF; 0 WNND) - Ellis (1 WNF; 0 WNND) - Liberty (0 WNF; 1 WNND) - Travis (1 WNF; 0 WNND) WNF = West Nile Fever WNND – West Nile Neuroinvasive Disease Data source: Texas Department of State Health Services Page 3 of 3
© Copyright 2024 ExpyDoc
