WASHINGTON – U.S. manufacturing posted a strong gain in October to the highest level in two years even as coronavirus cases have begun to surge again in many parts of the country.The Institute for Supply Management, an association of purchasing managers, said Monday that its manufacturing index rose by 3.9 percentage-points to a reading of 59.3% last month, up from 55.4% in September.It was the highest level for this closely watched barometer of manufacturing health since September 2018.