West Nile Virus Update

West Nile Virus (WNV)


As of today, 9/17/2018, ODH is reporting 23 human West Nile virus (WNV) cases, including 2 fatalities, and 6 asymptomatic WNV viremic blood donors in Ohio.  Additionally, 17 equine cases have been reported from 11 counties.  WNV activity in mosquitoes remains high at this time and virus activity has been reported from 64 Ohio counties so far this year.  The graph below shows where we are this year with infection rates in mosquitoes compared to 2012, a high WNV activity year (red dashed line), and 2016, a relatively normal WNV activity year (green dotted line):

La Crosse Virus (LAC)


ODH is also reporting 17 La Crosse (LAC) virus cases and 2 unspecified California virus cases.  Cases include 12 females and 7 males, ages 3-17, from 13 Ohio counties.  The rainfall we’ve had this summer has continuously filled tree holes and containers with water, creating ideal conditions for tree hole mosquitoes (vectors of LAC virus) to breed.  For more information about LAC and other arbovirus cases and surveillance data in Ohio, see the current Ohio arbovirus surveillance update at http://www.odh.ohio.gov/arboupdate.

Surveillance season is beginning to wind down, but with continued warm temperatures and active infected mosquitoes, the risk of new infections will continue until we have a hard freeze.  In fact, we have several suspect cases under investigation and we continue to receive new reports each week.  With this in mind, please continue your community and public education efforts focusing on personal protection and source reduction.  For more information, please check out our website at ohio.gov/mosquito or you can call the Zoonotic Disease Program (ZDP) at (614) 752-1029.