The US state of Indiana had nearly 10 times more Covid-19 infections than officially reported in late April, according to the first statewide random sample study conducted in the country worst affected by the pandemic . According to the survey, an estimated 187,802 Indiana residents – around 2.8 per cent of those aged 12 and over – had been infected with the coronavirus, 9.6 times higher than the 17,792 confirmed cases between April 25 and 29. The study, of more than 3,650 people in a statewide population of 6.73 million, was released on Tuesday by the US Centres for Disease Control and Prevention. It found the estimated infection-fatality rate in Indiana was 0.58 per cent, about six times the 0.1 per cent mortality rate for influenza. Researchers said this was lower than the infection-fatality rate of 1.3 per cent on a cruise ship, but consistent with an extrapolated rate in China of 0.66 per cent. The survey found those with a household member diagnosed with Covid-19 were 15 times more likely to also have a positive test result. More than 44 per cent of people with active infection reported no symptoms during the two weeks before testing. The report also showed a remarkably higher likelihood of infection among racial minorities. Hispanics in Indiana had an overall prevalence of 8.3 per cent, compared to 2.3 per cent for non-Hispanics. “The significantly higher observed prevalence in minority communities might have been due in part to social conditions that increased transmission opportunities, including minorities being disproportionately represented among essential workers,” said the researchers from six health bodies in Indiana. They said this suggested a need for communication strategies tailored to the culture and languages of local communities, as well as more testing and contact tracing resources to prevent additional infections in these groups. Social distancing, consistent and correct use of face coverings and hand hygiene were needed to prevent Covid-19 infection and deaths and reduce a surge in hospitalisation, given that many people remained susceptible to the virus, the researchers said. US has more than one-quarter of world’s 15 million coronavirus cases They also said the study’s findings and the relatively low statewide prevalence suggested stay-at-home orders – in effect from late March to early May – likely minimised community spread and were an important approach to prevent transmission in the absence of a vaccine. The study also showed the importance of ensuring effective protection for other members of households in which Covid-19 patients were undergoing home isolation, they said.