Troubling spikes in coronavirus infection rates have been reported in several US states, mainly in the South and West, a day before President Donald Trump is due to preside over an Oklahoma campaign rally that will be America’s largest indoor gathering in months.

Wall Street jitters over a resurgence in Covid-19 cases as states moved to reopen long-stifled commerce and ease social-distancing measures helped drive down major US stock indexes, reversing earlier gains.

According to Reuters, experts say expanded diagnostic testing accounts for some, but not all, of the growth in cases, and that the mounting volume of infections was already elevating hospitalisations.