Staff and pupils were sent home from Hottsbridge Primary in Waterbeck, pictured, this morning after the positive case was discovered.
It comes as figures show that cases of coronavirus are starting to creep up again in Dumfries and Galloway.
There were 32 positive cases recorded in the region in the seven day period up to yesterday.
This is more than three times as many in the previous week, when just nine were found.
NHS Dumfries and Galloway say the number of new close contacts has also jumped, from 17 to 244 in the last week.
However, the number of PCR tests carried out in the week ending April 25 was 3324, down slightly.
The nationally calculated seven day positivity rate for this area is currently estimated to be around 0.4 per cent.
Health officials are currently managing an outbreak of cases localised in Upper Nithsdale.