Indiana West Nile Virus 2025 Update

The Indiana Department of Health has a new Mosquito-Borne Illness Dashboard (↗) featuring two statewide maps. These maps show counties with mosquitoes and people infected by the West Nile Virus. The right-side map shows human infections. So far in 2025 as of September 5th, there were 10 people infected in the counties of Bartholomew (1), Hamilton (1), Madison (1), Marion (4), Vanderburgh (6), and Wells (1).

Almost all counties have at least one infected mosquito (based on test results) except the following ones mostly in Southern Indiana: Crawford, Dubois, Jefferson, Lawrence, Martin, Orange, Owen, Perry, Pike, Vermillion, and Washington. Union County has not tested for mosquitoes so far this year, or the test results have not been updated on the map. At first, the left map shows Hamilton County (Carmel, Fishers, Noblesville, Westfield, etc.) with the most mosquito infections at 128. However, the Collection tab and corresponding mosquito collection map shows this county tested a tremendous amount of mosquitoes (28,112) for the virus resulting in the inflated infection number. By comparison, Marion County (Indianapolis area) has 48 mosquito infections based on 9,847 tests.

Indiana's 1st Report of West Nile Virus in 2019

Several days ago, health officials in Elkhart County, Indiana, USA reported the first lab-tested mosquitoes infected with the West Nile Virus in Indiana this year. The West Nile Virus can be transmitted to people, so precautions such as applying DEET insect repellent and dumping water from various outdoor items (watering cans, old tires, etc.) are recommended. Hoosiers *use to be able to* stay up-to-date on the geographic distribution of the West Nile Virus by visiting the Indiana State Dept. of Health's interactive Arboviral Encephalitides map. That website — https://gis.in.gov/apps/ISDH/Arbo/ — is now defunct. Similar websites are available for residents of some other states as well.

30 Hoosiers Infected by the West Nile Virus

As the mosquito-swatting season continues to wind down in Indiana and elsewhere in the UNITED STATES, Indiana State Department of Health's interactive Arboviral Disease map reveals the number of people infected by the West Nile Virus: 30. This is not too far away from last year's 26 human infections, but compare this to the 9 infections seen in 2014. Throughout 2018, people were infected in these counties: Allen (5), Delaware (3), Elkhart (2), Grant (1), Hamilton (4), Hendricks (1), Huntington (1), Lake (4), LaPorte (1), Marion (2), Porter (1), Vanderburgh (4), and White (1).

688 mosquitoes in 87 out of 92 Hoosier counties tested WNV-positive in lab tests throughout the year. 18 horses were infected as well, especially in Adams County (10 cases) but also in Harrison (1), Jay (3), Lake (1), Noble (1), Tippecanoe (1), and Whitley (1). For the first time in recent years, Eastern Equine Encephalomyelitis (EEE) infected horses: one each in Kosciusko and Whitley counties. For more information about the West Nile Virus situation in Indiana this year and in the past, access the All About Indiana webpage (↗) on GeoFact of the Day.

9 Counties have West Nile Virus Mosquitoes — Indiana 2018

As of Monday, July 16th, 2018, nine counties in Indiana tested mosquitoes and have confirmed West Nile Virus in some of those mosquitoes. The nine counties are Allen (2 batches with WNV), Bartholomew (1), Carroll (1), Elkhart (2), Hamilton (1), Marion (6), Monroe (1), Putnam (1), and Tippecanoe (2). Please consider precautions to prevent being bit by mosquitoes, since the West Nile Virus can cause distressful side effects — especially in children and elderly people. Wear lightweight but long clothing to cover bare skin, spray repellent containing DEET on yourself when enjoying the outdoors (especially at dusk), and empty water that collected outside in containers, etc. so that more mosquitoes cannot be born. Stay up to date on the Hoosier West Nile Virus situation with the Indiana Department of Health's Interactive Infection Map. This website has individual maps for mosquito infections, bird infections, equine/horse cases, and if people contract the non-contagious virus.

2 People Contract West Nile Virus — Indiana 2017

Two people from different parts of the state recently contracted the West Nile Virus on Friday, June 9th. These infections were discovered at hospitals in Hamilton and Lake counties. So far, no mosquitoes have been confirmed to have WNV in lab-test results in these counties. Therefore, these individuals may have been infected in other areas where WNV-infected mosquitoes are present for this year, or locally despite the lack of confirmed mosquito infections in Hamilton and Lake counties. To track WNV infections among Hoosier mosquitoes and people throughout the rest of spring, summer, and fall seasons, access the Indiana St. Department of Health's Arboviral Disease Map. For a nationwide outlook on arboviral viruses and diseases such as Chikungunya, Dengue, Saint Louis Encephalitis, and West Nile Virus, access the CDC/USGS interactive disease map (diseasemaps.usgs.gov/mapviewer link now defunct).

First Mosquitoes to Contract West Nile Virus — Indiana 2017

It's another season of mosquitoes "out for blood" in the United States and elsewhere, and health officials are testing for West Nile Virus in those bloodsuckers. In Indiana, the first lab-tested batch of mosquitoes with the WNV have been confirmed in a neighboring county southwest of Indianapolis — Morgan County, to be exact. Therefore, residents of rural areas and communities including Martinsville, Mooresville, Bethany, Brooklyn, Centerton, Chetwynd, Cope, Eminence, Exchange, Five Points, Landersdale, Little Point, Mahalasville, Monrovia, Morgantown, Paragon, Wakeland, Whitaker, and Wilbur should be particularly wary of mosquitoes.

The good news: only a very small percentage of local mosquitoes (likely less than 1%) carry the West Nile Virus, and many WNV-infected people do not experience fever or other symptoms. Regardless, it's still a good idea to take precautions to prevent being bit — especially with the use of insect repellent (should include DEET) and protective clothing to cover skin. To track WNV infections among Hoosier mosquitoes and people throughout the rest of spring, summer, and fall seasons, access the Indiana St. Department of Health's Arboviral Disease Map.

Updated West Nile Virus Map for Indiana

The above GeoFact of the Day Blog map shows the Indiana counties where mosquitoes and people were infected with the West Nile Virus in 2015 so far. Updates are always found on my All About Indiana page.

Indiana W. Nile Virus Update, 2015

In Indiana, there are over 460 lab tests in which mosquitoes tested positive for the West Nile Virus so far in autumn of 2015. Additionally, a total of 15 people contracted the West Nile Virus in the following counties: Allen, Bartholomew, Hamilton, Hendricks, Howard, Huntington (2), Jasper, Lake, Madison, Marion (2), Saint Joseph, and Vanderburgh (2).

4 More Human W. Nile Virus Cases in Indiana, 2015

After posting a GeoFact of the Day Blog post about the West Nile Virus in Indiana on September 21st, four more cases of human infections of the West Nile Virus have occurred. There are two people infected in Vanderburgh County, one person in Howard County, and another person in Marion County. An updated map of mosquito infections and human virus cases are found at gis.in.gov/apps/ISDH/Arbo.

Eighth Human West Nile Virus Case in Indiana, 2015

The eighth person in Indiana who contracted the West Nile Virus from a mosquito lives in Hendricks County. One resident each in the counties of Bartholomew, Hamilton, Huntington, Jasper, Madison, Marion, and Saint Joseph have also contracted the West Nile Virus in 2015. An updated map of mosquito infections and human virus cases are found at gis.in.gov/apps/ISDH/Arbo/.

Indiana West Nile Virus Update

Since my previous West Nile Virus update all the way back in early September, there have been four more human cases of the West Nile Virus, which can be spread to few humans by few mosquitoes. It is important to note that humans cannot contract the virus from other humans, only from mosquitoes. Porter County has another human case, bringing the Northwest Indiana county's 2014 total to 2 humans infected by the West Nile Virus. Lawrence, Marion, and Putnam are the other three counties with recent human cases compared to my earlier post; Hancock County confirmed a human case in early September.
There are 163 total lab-confirmed mosquito infections in 52 counties. Visit the Indiana State Department of Health's online arboviral disease map for details. The All About Indiana page below the GeoFact of the Day Blog's header image also has updates on the West Nile Virus in Indiana.

Second Indiana Person with West Nile Virus in 2014

The Indiana State Department of Health reports that another Hoosier person contracted the West Nile Virus from a mosquito infection. This occurred in Hancock County, east of Indianapolis. Lab results show there are over 80 mosquito samples infected with the West Nile Virus in more than 30 counties. There are many mosquitoes without the West Nile Virus, but it still is wise to be protected from mosquito bites. One important tip is to remove standing water from outdoor objects like unused flower pots; bird baths should be emptied from time to time, especially if there are mosquito larvae swimming in them. This certainly helps prevent many mosquitoes from growing up into bloodsuckers!

Indiana West Nile Virus | August 30, 2014

Thankfully, only one person so far was infected by the West Nile Virus this year, and this occurred in Porter County. 28 other Indiana counties out of 92 total counties report West Nile Virus in some mosquitoes. With number of infections in parentheses, these 28 counties are Adams (1), Allen (4), DeKalb (2), Delaware (2), Dubois (1), Fulton (1), Greene (1), Hamilton (9), Howard (1), Jefferson (1), Johnson (1), LaGrange (2), Lake (3), Marion (10), Marshall (1), Morgan (5), Newton (1), Orange (1), Pike (1), Rush (2), Saint Joseph (3), Steuben (1), Sullivan (1), Switzerland (1), Tippecanoe (1), Vanderburgh (6), Wabash (3), and White (1).

Go to the Indiana State Department of Health's Arboviral Disease Mapping website for future updates on the West Nile Virus situation.

West Nile Virus Returns to Indiana

You may have followed the GeoFact of the Day Blog's extensive 2013 coverage of the West Nile Virus, a mosquito-borne illness that occurred in almost every Indiana county last year (click the West Nile Virus post label below or access the All About Indiana page for more info). Well, the West Nile Virus is making its annual return to the Hoosier State. A few mosquitoes in DeKalb, Dubois, Marshall, and Pike Counties are infected with the WNV. Interestingly, DeKalb and Marshall are in the north, while Dubois and Pike are many miles away in the south.
Keep up-to-date on West Nile Virus information with the GeoFact of the Day Blog, and you can always access the Indiana State Department of Health's West Nile Virus Map.

Indiana West Nile Update | October 4, 2013

The counties of Fountain, Vermillion, Warren, and Wayne now have small numbers of mosquitoes with the West Nile Virus. There is now a human infection in Marion County, the location of the state capital: Indianapolis. In Decatur County, a human had an infection of the La Crosse Encephalitis Virus.
This info came from the Indiana State Department of Health arboviral disease map.

More Hoosiers Infected by West Nile Virus

According to the Indiana State Department of Health's map, there are now eleven Hoosiers infected by the West Nile Virus. There is one infection each in Bartholomew, Elkhart, Floyd, Hamilton, Ripley, Saint Joseph, Vanderburgh, and Vigo counties. Porter County has the most infections with three.

Nine new counties have confirmed West Nile Virus in a very small number of mosquitoes without human infections. They are Benton, Dubois, Harrison, Jasper, LaPorte, Randolph, Rush, Union, and Washington counties.

A Human West Nile Virus Infection in Saint Joseph County

October 7th Update: I noticed that, on the map of which you can access with the link below, Saint Joseph County did not have a human infection case anymore. This may mean that the person was successfully treated for the symptoms.

On September 13th, Saint Joseph County of Northern Indiana/Michiana joined the counties of Floyd, Porter, and Ripley because, in these counties, at least one person has been infected with the West Nile Virus, according to the Indiana State Department of Health's Arboviral Map.
Also, the newest counties with WNV infections in a very small amount of mosquitoes are Clay, Hancock, Pulaski, Putnam, and Wells. There are 70 out of 92 Indiana counties in which the West Nile Virus infected a small population of mosquitoes.

New Human West Nile Virus Cases in Indiana

According to the Indiana State Department of Health and its online Arboviral Disease Map, there are new cases of humans infected by the West Nile Virus: two in Porter County and one in Floyd County.
More Indiana counties are added to the list of counties that confirmed the West Nile Virus in mosquitoes yet do not have human infections at this time. These counties are Fayette, Gibson, Greene, Lawrence, Scott, and Wabash.
Visit my All About Indiana page to see an updated map of West Nile Virus in Indiana.

Indiana West Nile Update | August 28th, 2013

Ten more counties have confirmed the West Nile Virus in mosquitoes, albeit the risk of WNV is still very low in these counties. They are Bartholomew, Blackford, Boone, Clark, Floyd, Henry, Huntington, Porter, Posey, and Warrick. The Indiana State Department of Health's Arboviral Disease Map always have the latest updates.

Indiana West Nile Update | August 26th, 2013

As of Monday, August 26th, according to the Indiana State Department of Health's Arboviral Disease Map, another set of nine counties confirmed that mosquitoes sent for lab testing have the West Nile Virus. Still, the WNV is definitely not widespread — a small percentage of mosquitoes have the WNV. Likewise, Hoosiers are still at a low risk. Colored in white in the map, the nine counties are Cass, Elkhart, Howard, Johnson, Miami, Owen, Perry, Shelby, and Spencer. Cass, Howard, and Miami are the three bordering counties in North-Central Indiana. Elkhart County is in Northern Indiana and the Michiana region. Johnson, Owen, and Shelby counties are in South-Central Indiana, while Perry and Spencer counties are found along the Ohio River in Southern Indiana.