Other Animal Species Large and growing list of animals that have tested positive for WNV Current list at U.S. Geological Survey’s National Wildlife Health Center website at:

Dogs Small Study (4 animals) Low levels of viremia induced None clinical (Unpublished data to date-Michel Bunning, CDC-DVBID)

Cats Small study Viremia a little higher and longer than dogs Parenteral: mild temp for 2-3 days no CNS signs Oral: fed infected mice same level of viremia, no illness Therefore-could be source for mosquitoes

WNV Positive Humans

Positive Human WNV Cases cases 51 deaths

/20/20027/27/2002 8/3/2002 8/10/20028/17/20028/24/20028/31/2002 9/7/2002 9/14/20029/21/20029/28/200210/5/2002 Onset Date Number of Cases Confirmed Probable Onset Date of Symptoms Among Human West Nile Virus Cases in Michigan as of November 5 th, 2002

Age Groups of WNV Cases Michigan 2002

Michigan Case Statistics: All Cases Age range: 9mo-95yrs Ave Age: 57.6 % Female: 45 % Male: 55 Deaths Age range: yrs Ave Age: 74.5 % Female: 41 % Male: 59

Types of Illness 80% asymptomatic 20% have flu-like symptoms <1% have meningo-encephalitis/flaccid paralysis/other serious sequelae ~10% of those with serious CNS signs die

West Nile Meningo-encephalitis Fever, headache Altered mental status AND/OR Stiff neck with CSF pleocytosis or elevated protein Flaccid paralysis (poliomyelitis-type)

Diagnosis of Human Cases CSF is best specimen IgM Capture ELISA PRNT (measure of IgG) Serum-need paired sera to document a rise in titer SLE cross reaction-must run concurrently

New Modes of Transmission Transplant Transfusion Breast milk Trans-placental Occupational

Bird Surveillance Goals: Collect information about dead bird sightings Collect specimens for laboratory testing Predict level of risk for human infection Target intervention/prevention measures

Methods of Bird Surveillance Citizen reports of dead or sick birds via hotline and website. Laboratory testing of appropriate bird specimens. Bias: Requires a person to find the bird and report it or submit it. Larger population areas will have more birds reported.

West Nile Virus Hot Line Started in 2001 Toll Free #: Citizens call in to report dead bird We requested reports of dead corvids Request address and day bird was found, as well as willingness to collect bird for testing Received 9,279 phone reports in 2002

WNV Hotline Calls* / * >35,000 calls in Aug & Sept

Web-based Reporting Accessed via Pilot program with Michigan State University Received 1350 reports via the web

350 4/17/2002 5/1/2002 5/15/20025/29/20026/12/20026/26/20027/10/20027/24/2002 8/7/2002 8/21/2002 9/4/2002 9/18/200210/2/2002 Date of Call Number of Calls Phone Reports of Dead Birds in Michigan as of November 26 th, 2002

Bird Surveillance Totals Logged over 10,500 reports of dead birds and other animals About 13% of reports came via the web 65% of dead birds reported were corvids (these were requested)

Phone Reports of Dead Birds versus Human Cases in Michigan as of November 26 th, 2002

Potential Problems for Bird Surveillance in 2003 Bird immunity-crows could be less sensitive indicator of WN activity Lack of web-based reporting for local and state reporting of diseases Monitoring of bird reporting is labor intensive without technological support Need to share data amongst agencies

Prevention Source reduction Personal protection Mosquito control Vaccine-horses only at this time

What Happened in 2002? Expansion of endemic area to 44 states in the US Huge epizootic/epidemic-especially in the Great Lakes and southern states New modes of transmission discovered Over 4000 human cases with more that 260 deaths

What to Expect in 2003? Complete spread to the 48 states in the continental U.S.? Bird immunity? Human herd immunity? Sporadic occurrence? ???????