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Arbovirus, 2010

Arbovirus, 2010. May 20, 2010 Susan Stowers Greg Chrislip Jonah Long Danae Bixler. Objectives. After the call, participants should understand: Descriptive epidemiology (temporal, seasonal trends and occurrence by age, gender and location) of LAC

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Arbovirus, 2010

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  1. Arbovirus, 2010 May 20, 2010 Susan Stowers Greg Chrislip Jonah Long Danae Bixler

  2. Objectives After the call, participants should understand: • Descriptive epidemiology (temporal, seasonal trends and occurrence by age, gender and location) of LAC • Recent mosquito and bird data for West Nile • Purpose and methods for avian, mosquito and human surveillance for arbovirus in West Virginia. • Process for human case ascertainment and investigation • Process and rationale for enhanced passive surveillance for 2010

  3. West Virginia Arbovirus Surveillance Data Susan Stowers Zoonotic Disease Data Analyst II

  4. 2009 West Nile Virus Summary • West Nile Virus (WNV) • 0 Human cases • Others: • 3 WNV positive birds (Out of 35 tested) • (Greenbrier, Hancock and Wetzel Counties) • 1 WNV positive horse (Fayette County)

  5. 2009 LaCrosse Encephalitis • 14 Human Cases • (10 Confirmed/4 Probable) • Age: • Range: 13 Months to 15 Years • Mean: 9 Years, Median: 10 Years • 4 Female/10 Male

  6. 2009 Mosquito Facts • 854 pools (54,267 mosquitoes) collected • 136 pools from five counties tested positive for West Nile Virus • (Cabell, Jackson, Kanawha, Ohio and Putnam)

  7. 2009 Mosquito Surveillance • Season was early – first positives in June • (normally not until July) • Two counties (Cabell and Ohio) contributed by doing mosquito sampling

  8. Conclusions • La Crosse encephalitis • Primary arbovirus of concern in West Virginia • Age < 15 • Southern counties • Forested areas • West Nile virus • Secondary concern • Lull in activity

  9. Human Surveillance of Arboviral Diseases: 2010 Season Update May 20, 2010 Jonah M. Long, MPH Zoonotic Disease Epidemiologist Division of Infectious Disease Epidemiology

  10. Overview • Human transmission • Reportable conditions • Case definition • Clinical • Laboratory • Epidemiologic investigation • Case investigation process

  11. West Nile Virus Transmission Cycle

  12. La Crosse Virus Transmission Cycle

  13. Purpose of Human Surveillance • Arboviral infections continue to have significant impact upon WV residents • Disease can be serious for vulnerable populations and treatment is supportive • Prevention is key • Data supports public health’s interest to prevent and control human infections

  14. What is Reportable in WV? • “Arboviral infection” per 64CSR7 • To be reported within 1 week to local health department (category IV) • This includes the following conditions…

  15. Arboviral Infection (Reportable) • LaCrosse encephalitis (LACV) • West Nile virus (WNV) • Saint Louis encephalitis (SLEV)* • Eastern Equine encephalitis (EEEV)* • Western Equine encephalitis (WEEV) • Powassan encephalitis (POWV) • Venezuelan Equine encephalitis (VEEV) • Japanese encephalitis (JEV) • Tickborne encephalitis (TBEV) • Chickungunya virus (CHKV) Occurs in USA and WV* *No human SLEV cases reported since 1997 Occurs in USA, could occur in WV* *Two WV Birds tested positive for EEEV 2002 Occurs outside the USA, but may arrive via travel…

  16. Case Definition • Clinical part of case definition: • Neuroinvasive: Fever and at least one of the following as documented by a physician: • Acutely altered mental status; OR • Other signs of acute neurologic impairment; OR • Increased white blood cell count in CSF + s/s meningitis • Non-neuroinvasive: Fever only (via clinician or patient), with no evidence of neuroinvasive disease

  17. Case Classification • Confirmed arboviral infection case: • Meets clinical criteria and has one of the following lab criteria: • Four-fold or more change in antibody titer from acute and convalescent serum specimens; OR • Isolation of virus; OR • IgM + in CSF by antibody capture EIA; OR • IgM + in serum by antibody-capture EIA and IgG + in same or later specimen using a confirmatory serologic test (i.e., neutralization or hemagglutination inhibition)

  18. Case Classification • Probable arboviral infection case: • Meets clinical criteria and has one of the following lab criteria: • Elevated but <2-fold change in titer of antibodies from acute and convalescent serum specimens; OR • IgM + in serum by antibody-capture EIA but with no confirmatory results of a test for IgG antibodies in the same or a later specimen

  19. Laboratory Hieroglyphics • Lab results can be tricky to interpret • Labs are critical for case ascertainment • Specimen type • Test methodology used • Sending specimens to OLS • Required if positive; otherwise recommended

  20. Example 1: Initial CSF findings… High white blood cell count in CSF indicative of meningitis, if clinical signs are also present (stiff neck, headache, etc)

  21. Example 2: Initial Serology… This IFA test result is not enough to classify the case; specimen should be sent to OLS for EIA test. Alternatively, a convalescent specimen could be IFA tested (rare)

  22. Example 3: OLS Findings… Based on this result, specimen type and test method, this case would considered to be PROBABLE

  23. Epidemiologic Investigation • This part of case investigation is critical • Site visit is necessary • Visualize environment • GPS coordinates • DMS: DDD° MM' SS.S" • DDM: DDD° MM.MMM‘ • DD: DDD.DDDDD°

  24. Epidemiologic Investigation (2) • Collect exposure data based on the relevant incubation period (typically 5 – 15 days) • Travel history (imported disease?) • Outdoor activities • Environmental risk factors (standing water, etc) • Provide education and recommendations based on findings

  25. Additional Response to Case • Take proactive stance • Consider notification of local healthcare providers • Consider press release • Template on DIDE website • Plug prevention messages!

  26. Arboviral Case Investigation Process

  27. Conclusion • Arbovirus surveillance is important and helps focus LOCAL interventions • Case definition for arbovirus consists of specific clinical and lab criteria • Specimens should be sent on to OLS • Epi investigation is a critical component

  28. ARBOVIRUS SURVEILLANCE 2010 GREG CHRISLIP PUBLIC HEALTH ENTOMOLOGIST

  29. WHY DO WE USE ANIMAL SURVEILLANCE? • Animal surveillance is conducted to find the virus…before there is spill-over into the human population.

  30. MOSQUITOSURVEILLANCE • Set an array of traps in areas that may have considerable West Nile activity. • Gravid traps would be set in the same areas every week. • Traps set on Mondays, mosquitoes would be collected on Tuesday, Wednesday, Thursday and Friday.

  31. MOSQUITO SURVEILLANCE • Can be tested for WNV, EEE, SLE and LAC • Test based on mosquito species • PCR

  32. What Makes A Good Site? • We need areas where there is water with a lot of organic matter in it..... • Municipal sewage treatment facilities, especially older ones • Sewage treatment package facilities serving mobile home parks and small communities • Sewage lagoons • Communities with large numbers of failing septic systems • Areas which flood easily and hold water

  33. WHAT IF WE FIND WEST NILE? • Sewage lagoons, sewage treatment package plants • Permitted by local health department • FIRST CONTACT PERMIT HOLDER! • Facility may need pumped • Vegetation should be cleared around lagoons • WVDEP –MANAGES WASTE WATER • If assistance is needed contact Regional WVDEP office.

  34. MONITOR DEAD BIRDS • Local Health is point of contact for dead bird surveillance. • Do you have last years test kit? • Don’t forget to request new transport media from OLS.

  35. 2010 Bird Testing • We test birds all year....January through December. • All wild bird species tested (no poultry) • Bird tested for WNV, SLE, EEE using PCR • Call DIDE for a testing number • Birds sent without a number may not be tested.

  36. BIRD SURVEILLANCE • Put on gloves and mask • Open the birds oral cavity and swap the inside with swab provided in the kit. • Place the swab into the media tube, breaking off the swab if it too long. • Refrigerated the swap until mailed to OLS • Avian Oral Swab Demonstration Video under West Nile of our website.

  37. EQUINE SURVEILLANCEWHAT IF WE FIND WEST NILE? • Tested for EEE and WNV at OLS using Mac-Elisa • Alert veterinarians and horse owners. • Horses not previously vaccinated • Two doses recommended 3-6 weeks apart • Annual booster shot before arbovirus season begins

  38. GENERAL PUBLIC • Make home bug tight • Use repellents • DEET • Picaridin • IR3535 • Oil of Lemon Eucalyptus • Empty standing water on property

  39. LHD MOSQUITO SURVEILLANCE • CABELL-HUNTINGTON • 8 Trapping Sites • 7,910 mosquitoes • 127 pools • 15 pools WNV positive • Pools of Ochlerotatus triseriatus WNV positive

  40. LHD MOSQUITO SURVEILLANCE • WHEELING-OHIO • 11 Trapping Sites • 3,896 mosquitoes • 122 pools • 21 pools WNV positive • Pools of Ochlerotatus japonicus WNV positive

  41. . LHD MOSQUITO SURVEILLANCE • Collections from Cabell and Ohio County health departments greatly supplemented state efforts, and demonstrated that local health departments can add to state efforts.

  42. Enhanced Passive Surveillance, 2010 • Season kick-off e-mail alert, May 3 • Local health departments, infection preventionists, laboratorians • Laboratory letter, May 10 • Laboratorians • Health alert, May 17 • Physicians

  43. Resources (1) • DIDE • www.wvidep.org => A-Z index => • Arboviral encephalitis • Information sheets • Model press release • West Nile encephalitis • Dead bird specimen collection video • Surveillance data • LaCrosse encephalitis • Information sheets • (800)-423-1271 • Office of Laboratory Services • http://www.wvdhhr.org/labservices • (304)-558-3530

  44. Resources (2) • Entomologist • Mosquito complaints? • 800-423-1271 • Surveillance? • 304-558-3530 … Ask for Greg • CDC • http://www.cdc.gov/ncidod/dvbid/arbor/index.htm • CEUs • https://wv.train.org

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