Ohio Vector-borne Disease Surveillance Update

The Ohio Department of Health (ODH) Zoonotic Disease Program, in partnership with ODH Laboratory, local public health partners, and sanitary district partners, conducts statewide vector-borne disease surveillance which includes monitoring for human and veterinary cases.

We will monitor for diseases transmitted by mosquitoes and ticks throughout the summer and fall and will report positive results and summary statistics on this website, updated each Friday at noon.

As of November 15, 2024

2024 Mosquito-borne Diseases

West Nile Virus

Mosquito surveillance:

Mosquitoes tested from 67 agencies in 55 counties, pooled into 13,501* samples.

West Nile virus positive mosquito pools from 41 counties:

Athens (2), Brown (1), Carroll (7), Clark (74), Clermont (3), Crawford (1), Cuyahoga (2), Darke (1), Delaware (3), Fairfield (7), Franklin (456), Geauga (17), Greene (2), Hamilton (45), Hancock (18), Harrison (3), Henry (8), Knox (4), Lake (10), Licking (54), Lorain (143), Medina (2), Meigs (4), Montgomery (7), Ottawa (15), Pickaway (3), Pike (2), Portage (57), Richland (29), Sandusky (11), Scioto (8), Seneca (5), Shelby (4), Stark (64), Summit (79), Tuscarawas (8), Union (21), Vinton (2), Warren (4), Wood (2), Wyandot (1), unknown county (8).

* In addition to samples tested by the Ohio Department of Health, Athens City-County Health Department, Columbus Public Health, Delaware Public Health District, Franklin County Public Health, and Licking County Health Department and test some of their samples.

Human surveillance:

West Nile virus disease human cases.

Sexes:

Ages:

From 10 counties:

Ashtabula (1), Auglaize (1), Cuyahoga (3), Franklin (1), Hancock (1), Henry (1), Lorain (2), Lucas (1), Stark (1), Wyandot (1).

Asymptomatic, viremic blood donors.

Asymptomatic, viremic organ donors.

Veterinary surveillance:

West Nile virus avian case.

West Nile virus equine cases.

La Crosse/California encephalitis virus

Mosquito surveillance:

Mosquitoes tested from 61 agencies in 51 counties pooled into 950 samples.

La Crosse virus positive mosquito pools from 2 counties:

Hancock (1), Morgan (1).

Human surveillance:

La Crosse virus human cases.

Sexes:

Ages:

From 4 counties:

Franklin (1), Holmes (1), Richland (1), Wayne (1).

Travel-associated mosquito-borne diseases

Chikungunya surveillance:

Chikungunya human cases.

Sexes:

Ages:

Traveled to 3 countries:

Cameroon (1), Ecuador (1), India (3).

Dengue surveillance:

Dengue human cases.

Sexes:

Ages:

Traveled to 16 countries:

Barbados (1), Brazil (2), Cape Verde (1), Costa Rica (2), Curacao (3), Dominican Republic (1), El Salvador (1), India (2), Mexico (4), Nicaragua (1), Peru (1), Philippines (1), Puerto Rico (2), St. Barthelemy (1), Thailand (1), U.S. Virgin Islands (2).

Zika surveillance:

Zika human cases.

Malaria surveillance:

Malaria human cases.

Sexes:

Ages:

Traveled to 23 countries:

Afghanistan (1), Angola (1), Burkina Faso (1), Burundi (1), Cameroon (7), Chad (2), Colombia (1), Congo DRC (1), Congo (4), Ethiopia (5), Ghana (4), Guinea (5), India (1), Kenya (3), Liberia (5), Mexico (1), Nigeria (6), Rwanda (1), Sierra Leone (10), Tanzania (6), Togo (1), Uganda (3), Venezuela (1), unknown African country (4), unknown country (2).

* Ohioans traveling to areas where local transmission is occurring should be aware of the ongoing situation and make every effort to avoid mosquito bites. Additional information can be found from the Centers for Disease Control and Prevention (CDC)'s Travelers' Health and Pan-American Health Organization websites.

2024 Tickborne Diseases

Lyme disease, anaplasmosis, babesiosis

Tick surveillance:

Blacklegged ticks identified.

From 67 counties:

Ashland (167), Ashtabula (4), Athens (93), Brown (1), Butler (6), Carroll (4), Champaign (9), Clark (2), Clermont (1), Clinton (32), Columbiana (4), Coshocton (10), Crawford (2), Cuyahoga (10), Delaware (6), Erie (12), Fairfield (89), Fayette (1), Franklin (68), Fulton (1), Gallia (2), Geauga (2), Greene (5), Guernsey (58), Hamilton (7), Harrison (59), Highland (1), Hocking (15), Holmes (209), Huron (1), Jackson (26), Jefferson (3), Knox (1), Lake (3), Lawrence (1), Licking (396), Logan (1), Lorain (3), Lucas (2), Mahoning (2), Marion (2), Medina (8), Meigs (5), Miami (3), Monroe (3), Montgomery (2), Muskingum (164), Noble (134), Perry (110), Pickaway (3), Pike (8), Portage (235), Richland (8), Scioto (1), Seneca (136), Shelby (31), Stark (11), Summit (32), Trumbull (1), Tuscarawas (33), Union (2), Van Wert (1), Vinton (32), Warren (2), Washington (116), Wayne (96), Wood (2), unknown county (1).

Lyme disease human surveillance:

Lyme disease human cases.

Sexes:

Ages:

From 72 counties:

Adams (1), Allen (1), Ashland (4), Athens (13), Auglaize (1), Belmont (71), Brown (2), Butler (5), Carroll (19), Champaign (1), Clark (5), Clermont (13), Clinton (2), Columbiana (72), Coshocton (48), Crawford (2), Cuyahoga (25), Darke (1), Delaware (10), Erie (4), Fairfield (35), Franklin (30), Fulton (1), Gallia (6), Geauga (7), Greene (2), Guernsey (62), Hamilton (23), Hancock (1), Harrison (35), Henry (1), Highland (1), Hocking (18), Holmes (32), Huron (3), Jackson (23), Jefferson (91), Knox (38), Lake (9), Lawrence (2), Licking (76), Logan (3), Lorain (18), Lucas (5), Madison (1), Mahoning (18), Medina (18), Meigs (4), Monroe (3), Montgomery (3), Morgan (12), Morrow (4), Muskingum (59), Noble (13), Perry (16), Pickaway (1), Pike (1), Portage (15), Richland (19), Ross (2), Sandusky (1), Scioto (1), Stark (59), Summit (39), Trumbull (24), Tuscarawas (90), Union (3), Vinton (4), Washington (22), Wayne (20), Wood (1), Wyandot (1).

Anaplasmosis human surveillance:

Anaplasmosis human cases.

Sexes:

Ages:

From 15 counties:

Adams (1), Allen (1), Carroll (2), Coshocton (1), Cuyahoga (2), Franklin (1), Hamilton (1), Harrison (2), Holmes (1), Jefferson (1), Knox (1), Medina (1), Portage (1), Summit (1), Trumbull (1).

Babesiosis human surveillance:

Babesiosis human cases.

Sexes:

Ages:

From 3 counties:

Cuyahoga (1), Medina (1), Summit (1).

Rocky Mountain spotted fever (RMSF)

Tick surveillance:

American dog ticks identified.

Human surveillance:

RMSF human cases.

Sexes:

Ages:

From 8 counties:

Athens (1), Clermont (1), Gallia (4), Hamilton (1), Jackson (5), Monroe (1), Pike (1) Scioto (1).

Ehrlichiosis

Tick surveillance:

Lone Star ticks identified.

Human surveillance:

Ehrlichiosis human cases.

Sexes:

Ages:

From 15 counties:

Adams (1), Cuyahoga (1), Erie (1), Gallia (1), Hancock (1), Harrison (1), Jackson (3), Jefferson (1), Medina (1), Meigs (1), Scioto (1), Summit (1), Tuscarawas (1), Union (1), Warren (1).

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