wnv062904

Information about wnv062904

Published on October 21, 2007

Author: Lucianna

Source: authorstream.com

Content

West Nile Virus:  West Nile Virus Emily Zielinski-Gutierrez, DrPH Lisa Lundgren, RN, MSN, FNP-C Division of Vector Borne Infectious Diseases (DVBID) National Center for Infectious Diseases Centers for Disease Control and Prevention Fort Collins, Colorado West Nile Virus (WNV) before 1996:  West Nile Virus (WNV) before 1996 First discovered in 1937 in the West Nile district of Uganda Mild feverish illness Severe illness, like meningitis or encephalitis, was rare Wide distribution in Asia, Eastern Europe, Africa WNV is an Arthropod-Borne virus:  WNV is an Arthropod-Borne virus Transmitted by mosquitoes Can infect people and other animals Similar to some other viruses (a Flavivirus, in the Japanese Encephalitis Antigenic Complex – e.g. similar family to Yellow Fever, St. Louis encephalitis virus) Slide4:  West Nile virus: Approximate geographic range as of 1998 Slide5:  WNV: Basic Transmission Cycle Most important cycle is from mosquito to bird to mosquito Amplifying hosts “Incidental” infections: unlikely amplifying hosts Slide6:  1999 2000 2001 2002 Slide7:  2003 2003:  2003 WNND County Level Incidence per Million, United States, 2003*:  WNND County Level Incidence per Million, United States, 2003* Incidence per million .01-9.99 10-99.99 >=100 WNND: West Nile Neuroinvasive Disease *Reported as of 4/9/2004 Transmission:  Transmission The MOST IMPORTANT route of infection is bite of infectious mosquito 2002 revealed novel modes of transmission Blood Transfusion Organ Transplantation Intrauterine Percutaneous exposure (occ. exposure) Breastmilk (probable) Screening of Blood Supply:  Screening of Blood Supply As of July 2003, all blood donated in US is being screened for WNV (nucleic acid amplification testing rather than antibody screening) Testing being conducted under IND Minipool vs. individual testing Presumptive viremic donors important for surveillance Will be updated in MMWRs/website Risk through transfusion very, very low Slide12:  Mosquito Vectors Important vectors vary by geography, e.g. Culex tarsalis (western states) Culex pipiens (Midwest, and elsewhere) Culex quinquefasciatus (south) Different behaviors – some fly very long distances Feeding habits, infection rates, breeding areas all important Nearly 50 species of mosquitoes capable (at least in the lab) of transmitting WNV Culex tarsalis feeding West Nile Virus—Clinical Disease:  West Nile Virus—Clinical Disease Slide14:  ~80% Asymptomatic ~20% “West Nile Fever” <1% CNS disease ~10% fatal (<0.1% of total infections) WNV Human Infection “Iceberg” For every case of illness involving the brain or spinal cord, ~150 total infections Very crude estimates WNV Fever:  WNV Fever Most people who get sick from WNV infection have WNV fever Time from exposure (usually by mosquito bite): 3-14 days Fever, chills, headache, fatigue Can be severe Nausea, vomiting (can be severe) Rash, usually not itchy, lasting a few days, mainly on chest, back, abdomen, and/or arms Usually better within a week, though persistent headache, fatigue common -- reports of weeks, even longer among otherwise healthy persons WNV Meningitis:  WNV Meningitis Similar to other meningitis from viruses Fever, headache, meningismus (neck stiffness, light bothering eyes) White blood cells in the cerebrospinal fluid Headache may be quite severe Most people improve, though persistent headache, fatigue common WNV Encephalitis:  WNV Encephalitis Severity ranges from mild confusion to coma and death People who are older (over 50) and/or who have chronic medical problems are usually the ones to have WNV encephalitis WNV Encephalitis :  WNV Encephalitis There are a number of other problems that people with WNV encephalitis may suffer: Tremor Myoclonus Quick, uncontrolled muscle jerking Problems with balance Dizziness WNV-Associated Flaccid Paralysis:  WNV-Associated Flaccid Paralysis Seen more frequently over the last 2 years Unclear how often it is happening: May be present in almost 15% of people with severe illness Affects relatively young people who are often healthy otherwise May not have fever or headache before paralysis WNV-Associated “Poliomyelitis-like illness”:  WNV-Associated “Poliomyelitis-like illness” Most cases of WNV-associated weakness that is persistent Clinical hallmarks: Onset early in infection Weakness can often be in only one limb Absence of numbness; pain sometimes present Diagnosis of WNV Infection (1):  Diagnosis of WNV Infection (1) Based on high index of clinical suspicion and obtaining specific laboratory tests Consider WNV, or other arboviral diseases such as St. Louis encephalitis, (esp. in adults >50 years) w/ unexplained encephalitis or meningitis (esp. in summer or early fall). The local presence of WNV enzootic (bird, mosquito, vet) activity or other human cases should further raise suspicion. Recent travel history also important. Diagnosis (2):  Diagnosis (2) Testing obtained through local or state health departments and increasingly through private labs Public health laboratories usually perform an IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA). W/ this test virus-specific IgM can be detected in nearly all CSF and serum specimens from WNV-infected patients at time of clinical presentation Serum IgM antibody may persist for + 1 yr., so physicians must determine whether the antibody is result of a previous WNV infection and unrelated to the current clinical presentation. Diagnosis (3):  Diagnosis (3) Most conclusive to identify person w/CNS infection is WNV-specific IgM in CSF using MAC-ELISA. Strongly suggests acute CNS infection. If no CSF and using serum samples, paired acute and convalescent-phase samples should be acquired. Acute at initial presentation, convalescent 7-14 days later. If no convalescent sample, acute specimen should be tested w/ MAC-ELISA. If IgM neg, acute WNV infection unlikely. If IgM pos and clinically compatible may be recent WNV infection (see note about other flavivirus infections). Diagnosis (4):  Diagnosis (4) Ideally MAC-ELISA should be performed using WNV and SLE viruses If WNV and SLE results similar – necessary to use PRNT to confirm. Recent vaccination (e.g. yellow fever) or related flavivirus infection may (e.g. dengue) may result in positive WNV MAC-ELISA. See: http://www.cdc.gov/ncidod/dvbid/westnile/resources/fact_sheet_clinician.htm Reporting:  Reporting Reporting procedures vary by state – refer to state coordinators/state websites Neuroinvasive disease is nationally notifiable, fever is not. States differ in their reporting of these. WNV: Illness Outcomes:  WNV: Illness Outcomes Current information limited Fatality rates 10-20% with severe disease die Fatalities primarily among elderly, immunosuppressed Unknown why some people do not get sick and some get extremely sick WNV—Long-term problems: “When will I get better?”:  WNV—Long-term problems: “When will I get better?” Fatigue Headache Difficulty with concentration or memory However—most people eventually DO get better (based on limited observations to date) May take many months WNV-Long-term outcomes:  WNV-Long-term outcomes WNV Poliomyelitis-like illness Outcomes vary Some people from 2002 and 2003 have had dramatic, almost complete recovery; others have had continued weakness We do not know why some people improve and some do not BUT Those with less severe initial weakness tend to have a better prognosis WNV--Treatment:  WNV--Treatment As is true for most viruses that cause human illness, there is no specific treatment for WNV Studies of: Antisense WNV-RNA Interferon-α WNV-specific immune globulin (“IVIG”) Results are only preliminary now Basic problem—drug has to be given very early, almost before the person is very sick Q: Once someone gets infected with WNV, can they get sick with WNV again?:  Q: Once someone gets infected with WNV, can they get sick with WNV again? A: If someone was sick with WNV last summer, they are probably immune. We think that this immunity lasts a long time (many years). However, mosquitoes can carry other viruses that can make people sick, so they should still take care to avoid mosquito bites! Q: When a person tests positive for WNV, does that mean that the virus is still in them?:  Q: When a person tests positive for WNV, does that mean that the virus is still in them? A: By the time someone gets sick, the virus is long-gone. The test measures the body’s reaction to the virus, to determine if the virus was present in the body recently or in the more distant past. Q: What is the status of a human vaccine for WNV?:  Q: What is the status of a human vaccine for WNV? A: Several agencies and companies are working on a vaccine for humans, and one is planned for testing next year. WNV Prevention:  WNV Prevention Treatment is symptomatic – therefore prevention of illness is crucial Preventive measures Personal Household Community / environmental WNV—Personal Protection:  WNV—Personal Protection Use mosquito repellent DEET (skin or clothing) Up to 50% concentration Permethrin (clothing) Wear long sleeves, pants Emphasize protection at times of high mosquito activity (dawn/dusk) or stay indoors Protect your house and yard Use/ fix screens Air-conditioning Empty water (breeding sites) Slide35:  After getting sick, recovery can take a long time, but most people do improve Avoiding getting bitten by mosquitoes is the only way to prevent WNV There is no treatment, but people are working very hard to develop one

Related presentations


Other presentations created by Lucianna

Nutritional Care of Burns
04. 01. 2008
0 views

Nutritional Care of Burns

spine2 no background
08. 05. 2008
0 views

spine2 no background

banking
14. 04. 2008
0 views

banking

emerging security threats
29. 09. 2007
0 views

emerging security threats

Thunderstorms
03. 10. 2007
0 views

Thunderstorms

i2 traffic shaping
03. 10. 2007
0 views

i2 traffic shaping

bind
07. 10. 2007
0 views

bind

prefix delegation requirement1
09. 10. 2007
0 views

prefix delegation requirement1

dipo
12. 10. 2007
0 views

dipo

Living Things
12. 10. 2007
0 views

Living Things

latinoamerica
22. 10. 2007
0 views

latinoamerica

Rachinsky
11. 10. 2007
0 views

Rachinsky

Slide presentazione
24. 10. 2007
0 views

Slide presentazione

feynman
16. 10. 2007
0 views

feynman

gt bot
13. 10. 2007
0 views

gt bot

fr summit marginson 230306
30. 10. 2007
0 views

fr summit marginson 230306

Accelerators CZ
15. 11. 2007
0 views

Accelerators CZ

Les Animaux du Zoo
11. 10. 2007
0 views

Les Animaux du Zoo

Rapport Nationale MAROC
23. 10. 2007
0 views

Rapport Nationale MAROC

Grammar essentials
16. 11. 2007
0 views

Grammar essentials

sponge
20. 11. 2007
0 views

sponge

Crans Montana 03 nieuw
15. 10. 2007
0 views

Crans Montana 03 nieuw

Workshop
02. 11. 2007
0 views

Workshop

NSF 12 6 2001
31. 12. 2007
0 views

NSF 12 6 2001

Class8
07. 01. 2008
0 views

Class8

toc wkshp nov03
18. 10. 2007
0 views

toc wkshp nov03

VCT Morocco
24. 10. 2007
0 views

VCT Morocco

NACADA Combined Workshop 11 04
29. 09. 2007
0 views

NACADA Combined Workshop 11 04

sky
13. 11. 2007
0 views

sky

file Kigali Strengthening Local
07. 01. 2008
0 views

file Kigali Strengthening Local

10638221831Maroc MinInt French
23. 10. 2007
0 views

10638221831Maroc MinInt French

ub geographicimagery051 001
27. 09. 2007
0 views

ub geographicimagery051 001

Presentación RR EXPORTA def
23. 10. 2007
0 views

Presentación RR EXPORTA def

prosper
28. 12. 2007
0 views

prosper

HPCN summary 7 5 2007
17. 10. 2007
0 views

HPCN summary 7 5 2007

ammosov
12. 10. 2007
0 views

ammosov

A NEW ENGLISH COURSE Book 3
20. 02. 2008
0 views

A NEW ENGLISH COURSE Book 3

Food Bank of New Jersey
29. 02. 2008
0 views

Food Bank of New Jersey

lewis
19. 10. 2007
0 views

lewis

XC Safety and mentor
03. 04. 2008
0 views

XC Safety and mentor

NA3
07. 04. 2008
0 views

NA3

Civitas Plus2006
18. 03. 2008
0 views

Civitas Plus2006

Ch14 7e
10. 04. 2008
0 views

Ch14 7e

Team2
11. 04. 2008
0 views

Team2

fmla
04. 10. 2007
0 views

fmla

retailcompetition
17. 04. 2008
0 views

retailcompetition

Using ILS
22. 04. 2008
0 views

Using ILS

shaw
16. 03. 2008
0 views

shaw

CSI Presentation 2007
19. 02. 2008
0 views

CSI Presentation 2007

NIST TDT2004
07. 05. 2008
0 views

NIST TDT2004

chapter3v2
15. 10. 2007
0 views

chapter3v2

MEDOPSBOOKFEB01
02. 05. 2008
0 views

MEDOPSBOOKFEB01

BostwPres
02. 05. 2008
0 views

BostwPres

555 Spanish
02. 05. 2008
0 views

555 Spanish

hexapod Shirke
02. 05. 2008
0 views

hexapod Shirke

Lung Expansion 1
02. 05. 2008
0 views

Lung Expansion 1

Aaron
02. 05. 2008
0 views

Aaron

CMI slides Feb05
01. 11. 2007
0 views

CMI slides Feb05

SAP1012
10. 03. 2008
0 views

SAP1012

lesson 4
15. 10. 2007
0 views

lesson 4

2006 APHA
05. 10. 2007
0 views

2006 APHA

probir
30. 03. 2008
0 views

probir

Rauf Presentation NEW
18. 10. 2007
0 views

Rauf Presentation NEW

IAJAPAN
09. 10. 2007
0 views

IAJAPAN

Mr Daisuke Matsunaga
09. 10. 2007
0 views

Mr Daisuke Matsunaga

3 KukaGLBThealthissues
29. 10. 2007
0 views

3 KukaGLBThealthissues

Bernard ANSELMETTI
24. 10. 2007
0 views

Bernard ANSELMETTI

NBII Newark 10 02
21. 10. 2007
0 views

NBII Newark 10 02

MarketingWorkshop 4 22 05rev1
24. 10. 2007
0 views

MarketingWorkshop 4 22 05rev1

FEESTDAGEN
06. 11. 2007
0 views

FEESTDAGEN

trainplanesandautomo biles
13. 03. 2008
0 views

trainplanesandautomo biles

NWA June00
05. 10. 2007
0 views

NWA June00

Panama 2004 Reporte
25. 10. 2007
0 views

Panama 2004 Reporte

SAKURA Yamamoto
25. 03. 2008
0 views

SAKURA Yamamoto

tiner presentation
04. 01. 2008
0 views

tiner presentation

aseancjp
09. 10. 2007
0 views

aseancjp

schools talk
29. 10. 2007
0 views

schools talk

BethkeA
02. 10. 2007
0 views

BethkeA

DeVidtsPresentation
11. 10. 2007
0 views

DeVidtsPresentation

Zhu Zhiyong
16. 10. 2007
0 views

Zhu Zhiyong

pres1 1
22. 10. 2007
0 views

pres1 1

AESC 2005 VERMONT Result
02. 11. 2007
0 views

AESC 2005 VERMONT Result