The United States surpassed 170,000 coronavirus deaths as health officials expressed concerns over Covid-19 complicating the autumn flu season.Deaths rose by at least 515 on Sunday, with Florida, Texas and Louisiana, leading the rise in fatalities.The United States has at least 5.4 million confirmed cases, according to a tally by Johns Hopkins University, the highest in the world. However that figure was likely an undercount as the country still has not ramped up testing to recommended levels…