VIRGINIA ARBOVIRAL ACTIVITY IN David N. Gaines, Ph.D. VDH Office of Epidemiology

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1 VIRGINIA ARBOVIRAL ACTIVITY IN 4 David N. Gaines, Ph.D. VDH Office of Epidemiology

2 HUMAN ARBOVIRUS CASES IN VIRGINIA IN 4

3 Human infections from mosquito and tick borne arboviral disease in Virginia in 4. West Nile virus - 7 cases; WN - neurological illness ( WNV fatality), and WN-fever; there was also infected blood donor who had no symptoms. St. Louis encephalitis - None recorded. La Crosse encephalitis - neurological case. Eastern equine encephalitis - None recorded. Powassan - tick borne encephalitis - None recorded.

4 Historic geographic occurrence of human WNV (7 cases), La Crosse encephalitis (LAC; 37 cases), and eastern equine encephalitis (EEE; 6 cases) in Virginia through 3, and location of new cases seen in 4. Historic WNV Human and LAC WNV, cases LAC and and EEE EEE Cases Infections in Virginia in Virginia Through in 4 3 WNV (+7 (7 = cases) 4 cases) WNV LAC Positive (37 cases) Blood Donor LAC EEE (6 (+ cases) = 38 cases) WNV Pos. Horse (3 ea. in 4) EEE Pos. Horse ( ea. in 4) 6

5 Imported human mosquito borne arboviral disease infections in Virginia in 4. Dengue fever (DEN) - 4 imported cases: most from tropical Americas (7 Haiti, Antigua, Honduras, Mexico, Santa Lucia and U.S. Virgin Islands); two cases also came from Asia and the Pacific ( Sri Lanka and Tahiti ). possible Zika virus case Chikungunya (CHIK) - imported cases: most from the tropical Americas ( El Salvador, Dominican Republic, 9 Haiti, 9 Puerto Rico, 3 Jamaica, Santa Lucia, U.S. Virgin Islands, Barbados, British Virgin Islands, Caribbean? (cruise ship), Dominica, Grenada, Honduras, Saint Martens, and Venezuela; one case also came from the Pacific Region (Indonesia). There were five other cases in which the patients had traveled to CHIK endemic countries, tested positive for CHIK, and had many typical CHIK symptoms, but could not officially be counted as CHIK cases because they did not have a fever. 3

6 Chikungunya in Virginia in 4. Virginia counties where chikungunya cases were counted

7 Imported dengue and chikunynya infections in 4 Dengue patients typically develop viremia (have virus circulating in their blood) starting a day before illness onset, and lasting for five days. Viremic persons can infect feeding Asian tiger mosquitoes. Of the 4 people with DEN, only two returned to Virginia during the active Asian tiger mosquito season (June September), but both had illness onsets after returning to VA. It is not known how soon chikungunya patients develop viremia before illness onset, but the viremic period can last for an average of seven days after illness onset. Of the 6 people with CHIK -positive lab results, 33 returned to Virginia during the active Asian tiger mosquito season, but only had their onset of symptoms after arrival in Virginia.

8 EASTERN EQUINE ENCEPHALITIS IN VIRGINIA IN 4 7

9 EEE surveillance in Tidewater VA in 4. 4 appeared to be a moderately high EEE activity year.. No human cases of EEE were recorded.. Surveillance for EEE in mosquito samples yielded the highest number of EEE positive pools ever recorded in VA, but most of these positive pools were detected through a tremendous effort by the surveillance program from Suffolk yielded fourth highest number of sentinel chickens to test EEE positive since, but the numbers were similar positive to what was seen in and As in 3, there was only one detection of EEE in an equine, but three captive birds also died of EEE at the Norfolk Zoo. 8

10 Virginia s yearly EEE surveillance indicators (EEE positives) from 3 through Humans: * Sentinel: Chickens Flocks Horses/ Equines: * Mosquito Pools: * Fatal human cases of EEE. * Other EEE positive animals = 9 equines, one goat, one alpaca and two captive birds Other EEE positive animals included three captive cassowary birds 9

11 In 4, a total of 7,73 mosquitoes (4,3 pools) were tested for EEE in Virginia, mostly by VectorTest; There were EEE positive pools. Mosquito Species # Mosqs. Tested # Pools Tested EEE Pos.* Pools EEE MIR Cs. melanura 9,4 4,3. Ae. albopictus, Cx. pipiens/restuans, Cx. salinarius 6,37 44 Cx. erraticus, Cq. perterbans 993 Oc. triseriatus 4 Ae. vexans 3 An. crucians 8 Cx. territans Oc. japonicus Grand Total 7,78,7 * All VectorTest EEE positive pools were confirmed by PCR and the PCR confirmation rate was %.

12 EEE MIR for Cs. melanura Number of Human EEE Cases Weekly EEE minimum infection rates (MIR)* for Cs. melanura, in Tidewater Virginia in 4; no human EEE cases were seen in EEE in 4 MIR Cs. melanura Week * Positive pools detected by VectorTest, and confirmed by PCR.

13 WEST NILE VIRUS IN VIRGINIA IN 4

14 WNV surveillance in Tidewater VA in 4. 4 appeared to be a moderately high year for WNV activity.. Seven human cases of WNV were recorded.. 4 had the 4 th highest number of WNV positive mosquitoes recorded, but the number was not much greater to the numbers detected in and Sentinel chickens also detected the nd highest level of WNV activity since 3, but the totals for positive chickens and flocks was only slightly different than was seen in There were three WNV infections detected in equines, mostly in the northwestern and northern part of VA. 3

15 West Nile virus surveillance indicators (WNV positives) in Virginia from through Human WNV Cases (7 Total) WNV+ Blood Donors Wild Bird Positives 93,4 6 3 Not Done Not Done Not Done Not Done Not Done Not Done Not Done Sentinel: Chickens Flocks Equine Positives Mosquito Positives * The 4 human WNV cases in this table only includes persons infected in Virginia. 4

16 In 4, a total of 37,493 mosquitoes (,378 pools) were tested for WNV in Virginia, by PCR, RAMP, or VectorTest. Mosquito Species # Mosqs. Tested # Pools Tested WNV Pos.* Pools WNV MIR Cs. melanura 93,9 4,3 4. Cx. pipiens/restuans 47,73 6, Ae. albopictus,49, Cx. erraticus 7, Cx. salinarius,98 4 Ae. vexans 6, Cx. spp. 3, Cx. pipiens, Oc. japonicus, 6 Cq. perturbans,78 Oc. triseriatus An. quadrimaculatus 339 An. punctipennis Ps. ferox 4 8 Cx. restuans 38 7 An. crucians 8 Cx. territans Grand Total 446,94 3,66 48 * Positive pools were confirmed by PCR, or conformed to RAMP standards used by VDH.

17 WNV MIR for Cx. (pip. + res.) Number of Human WNV Cases Weekly WNV minimum infection rates (MIR)* for Cx. (pipiens + restuans) and the number of human WNV cases in Northern Virginia in 4 3 WNV in 4 MIR Cx. (pip. + res.) 6 WNV Human Cases 4 MIR for 3; 4 WNV cases Week * Positive pools detected by PCR. 7

18 WNV MIR for Cx. (pip. + res.) Number of Human WNV Cases Weekly WNV minimum infection rates (MIR)* in Henrico County for Cx. (pipiens + restuans), and the number of human WNV cases in the Richmond Area (Richmond City) in 4 3 WNV in 4 MIR Cx. (pip. + res.) 6 WNV Human Cases Week * Positive pools detected by RAMP; most confirmed by PCR. 7

19 WNV MIR for Cx. (pip. + res.) Number of Human WNV Cases Weekly WNV minimum infection rates (MIR)* in the Tidewater Area for Cx. (pipiens + restuans) and the number of human WNV cases in Tidewater in 4 3 WNV in 4 MIR Cx. (pip. + res.) 6 WNV Human Cases Week * Positive pools detected by Vector Test; most confirmed by PCR. 7

20 Acknowledgements Laboratories: PA Dept. of Health Laboratory PA Dept. of Environmental Protection Laboratory Fairfax County Dept. of Health Laboratory The Virginia Division of Consolidated Laboratory Services (DCLS) The Virginia Dept. of Agriculture and Consumer Services (VDACS) Veterinary Laboratories Surveillance Programs: Alexandria Dept. of Health _ Vector Control Chesapeake Mosquito Control Fairfax County Dept. of Health -Vector Borne Diseases Program Hampton Mosquito Control Henrico County Mosquito Control Norfolk Dept. of Health Vector control Portsmout Mosquito Control Prince William County Vector Control Suffolk Mosquito Control Virginia Beach Mosquito Control Virginia Dept of Health (VDH)- Division of Environmental Epidemiology VDH - Division of Surveillance and Investigation VDH - Regional and District Epidemiology Staff 9.

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22 6 MIR 4 3 MIR Week