Another wave of states prepared to ease coronavirus restrictions on US commerce this week, despite health experts warning there is still too little diagnostic testing, while the White House forecast a staggering jump in the nation’s monthly jobless rate.

Colorado, Mississippi, Minnesota, Montana and Tennessee were set to join several other states in reopening businesses without the means to screen systematically for infected people who may be contagious but asymptomatic, and to trace their contacts with others they might have exposed.

Many merchants have voiced ambivalence about returning to work absent the prerequisite public health measures authorities have advocated.