A statewide study by Indiana University researchers estimates that at least 2.8% of Indiana’s population has been infected by the coronavirus, a rate about 10 times that shown by previous testing. Researchers set up 70 testing stations in cities and towns across Indiana, testing about 4,600 people at random between April 25 to May 1. They found 1.7% of people were infected at the time of the test and 1.1% tested positive for antibodies showing they were previously exposed. Researchers’ findings project that Indiana has seen a 0.58% fatality rate among those infected. That rate is almost six times greater than the fatality rate for seasonal flu, said IU professor Nir Menachemi who led the study in partnership with the Indiana State Department of Health. Nearly 45% of those infected reported experiencing no symptoms of the COVID-19 respiratory disease. The projected infection rate would mean about 186,000 Indiana residents had the coronavirus by the end of April, when the state health department reported fewer than 19,000 confirmed infections. The study also suggests that COVID-19 rates are much higher in minority communities, especially in Hispanic communities, where approximately 8% were currently or previously infected. While researchers do not definitively know why, it is possible that members of the Hispanic community in Indiana are more likely to be essential workers, live in extended family structures that include relatives beyond the nuclear family, or both. Menachemi said the results highlight the need for people to practice social distancing and wear masks in public to avoid unknowingly spreading the coronavirus. Furthermore, Menachemi said the needs to minimize the risk of infection spread will probably not go away until we have a vaccine or a really good treatment that can deal with everyone infected. Researchers will continue periodically testing a random sample of people in the state to learn how far the virus has infiltrated the state’s population so that policy decisions can be tailored to the situation.
While some researchers are finding a baseline for exactly how many people have contracted the coronavirus, others are working on predicting when an outbreak might occur. Daniel Johnson, an associate professor of geography in the IU School of Liberal Arts, is working with Columbia University’s Christian Braneon and researchers at the Centers for Disease Control to develop a predictive model of COVID-19 based on the physical environment, social environment and cases of infection. The researchers hope these predictions will provide enough lead time to give public health officials and the general public an opportunity to react to a coming surge. One major component of their research involves an aspect of the virus that is not yet known: its seasonality. In the early phases of the virus, many experts were predicting a drop in cases in the summer and a huge surge in the fall, thinking that COVID-19 would become a seasonal issue like the flu. But Johnson said that is not what we are seeing this summer. So, his team is looking at temperature, humidity and other things we know are linked to flu season and comparing it to Indiana’s COVID cases by county and census tract to look for links. Johnson is also examining the state’s socially vulnerable communities that have been hit disproportionately hard by the virus and how their local environments play a role. Johnson’s ultimate goal is to build a predictive system that can provide some sort of lead time on outbreaks and where they are going to occur, maybe within even a specific county. If successful, Johnson said there is the potential to developing a system similar to the National Weather Service’s watch and warning system, which would identify counties under a COVID-19 watch and allow public health officials to better provide guidance for things like school closures.