The results of a study released Wednesday show that as many as 186,000 Hoosiers might have been infected by COVID-19 by the end of April.

That study, conducted by the Indiana University-Purdue University Indianapolis School of Public Health and the Indiana State Department of Health, is designed to provide a better perspective on the impact the novel coronavirus has had on the state so far.

The first phase of the study, aimed at testing 5,000 Hoosiers from across the state, was conducted from April 25 to May 1. Individuals selected were not only tested for COVID-19, but also for antibodies of the virus, which would indicate they were infected previously.

The results, released during Gov. Eric Holcomb’s COVID-19 update Wednesday afternoon, are meant to be reflective of the state’s population as a whole.

Professor Nir Menachemi, who chairs the Health Policy and Management Department of the Richard M. Fairbanks School of Public Health at IUPUI, said the participants included in the first testing period included 3,600 randomly selected Hoosiers and more than 900 volunteers. That testing occurred from April 25 through May 1.

Of those tested, 1.7% were infected at the time of the test and 1.1% tested positive for COVID-19 antibodies, Menachemi said.

Using that result, he said it is estimated 186,000 Hoosiers had been infected with the virus by April 29.

The number of deaths from COVID-19 reported to the state department of health through that same day was 1,080, meaning the virus has an estimated rate of fatality of 0.58%, he said. The season flu had a death infection rate of 0.1.

“At the same time, the state was only aware of about 17,000 cumulative cases, not including deaths, suggesting that the true impact of the virus was nearly 11 times greater than conventional testing had informed us,” Menachemi said.

Of those who tested positive during the study, 44% were said to have shown no symptoms.

While the results are preliminary, Menachemi said he expects they are fairly accurate and will not change much following a peer review.

He said the study also found people living in a household with a person infected with COVID-19 were 12 times more likely to be positive themselves.

That finding, coupled with the relatively low 2.8% infection rate, strongly suggests social distancing policies played a critical role in curbing the spread of the virus and containing to within households as to opposed to within the community, Menachemi said.

“The good news is that by slowing the spread of the virus we now have bought some time to determine the best way forward,” he said. “However, it is important to stress that the vast majority of people in Indiana have not been infected and represent the minimum pool of still susceptible individuals.

“Therefore, as we slowly phase back and reopen the economy, we need to be extra vigilant with any and all safety precautions so we do not lose the ground we gained by hunkering down,” he said.

Three additional rounds of testing involving at least 5,000 Hoosiers each time are planned with the next round set for early June.

The ISDH announced Wednesday that 409 additional Hoosiers have been diagnosed with COVID-19 through testing at ISDH, the Centers for Disease Control and Prevention and private laboratories.

That brings the total number of Hoosiers known to have the novel coronavirus to 25,473 following corrections to the previous day’s total.

A total of 299 Jackson County residents have tested positive for the virus, an increase of 14 from Tuesday’s total.

Intensive care unit and ventilator capacity remains steady. Around 42% of ICU beds and more than 80% of ventilators were available as of Wednesday.

A total of 1,482 Hoosiers have been confirmed to have died of COVID-19, an increase of 38 over the previous day. The death of one Jackson County resident has been listed as related to COVID-19.

Another 137 probable deaths in the state have been reported based on clinical diagnoses in patients for whom no positive test is on record. Deaths are reported based on when data are received by ISDH and occurred over multiple days.

To date, 154,083 tests have been reported to ISDH, up from 150,510 on Tuesday. This includes 1,294 Jackson County residents tested to date.

Per 10,000 residents, 292.6 Jackson County residents have been tested. Also, there have been 67.6 positive cases per 10,000 residents, and the fatality rate is 0.2 per 10,000.