WASHINGTON (NYTIMES) - A Trump campaign adviser, Mr Corey Lewandowski, and Republican National Committee chief of staff Richard Walters have tested positive for the coronavirus, bringing the latest outbreak among United States President Donald Trump's aides and advisers to 14 people.

Mr Lewandowski and at least four others - Mr Trump's chief of staff, his political director, a campaign adviser leading the efforts to challenge election results, and the housing secretary - attended an election night party at the White House where hundreds of people mingled for hours, many without masks.

They join at least 20 members of Mr Trump's administration, campaign and inner circle who have contracted the virus since late September, after an earlier outbreak among White House residence staff.

It is not clear whether the outbreaks are connected, but the recent spate of cases reflects a lax approach to preventing infections at the nation's highest level of government - including an overreliance on rapid testing and the dismissal of mask wearing and social distancing - that did not appear to change even after the President was hospitalised with Covid-19 in early October.

Mr Tom Frieden, who served as the director of the Centres for Disease Control and Prevention under President Barack Obama, last week noted the lack of control measures at the White House and suggested the new cases could be a part of the same outbreak from late September.

The waves of cases have touched members of Mr Trump's family, campaign, administration and staff, some of whom have not isolated for recommended periods after infection and have continued to flout basic coronavirus rules.