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 today 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. Any reading above 50 signals that manufacturing is expanding.

The gauge had fallen into recession territory from March through May as much of the country shut down in an effort to contain the coronavirus.