Scarlet fever has been confirmed at two more Dundee schools, bringing the number affected to 11.
Cases have now been reported at Eastern Primary in Broughty Ferry and among the nursery class at Ballumbie Primary in Whitfield.
The other primaries affected over the last few weeks have been Downfield, Forthill, Craigiebarns, Rowantree, Longhaugh, Hillside, St Peter and Paul’s and Barnhill.
Baldragon Academy also issued scarlet fever warning letters to parents.
The new cases came to light a week after council bosses said they believed the worst of the outbreak was over.
Unless parents notify their schools when their child becomes ill, an accurate estimation about the number of children affected cannot be made as it is no longer a reportable disease in Scotland.
However, on the basis of the number of children attending each school where scarlet fever has been reported, more than 4,000 children may have been exposed to the contagious disease across Dundee.
Scarlet fever can be identified by a pink-red rash that feels like sandpaper and is most common in young children, though adults can also be affected.
Other symptoms include a sore throat, high temperature and a flushed face.
According to public health officials in England, reported cases of scarlet fever are at a 24-year high.
Dr Syed Ahmed, a consultant at Health Protection Scotland, said: “We are aware of the increase in certain primary schools.”
While he admitted that an increase in mild and moderate cases of scarlet fever can lead to more invasive forms, Dr Ahmed said the outbreak in Tayside should not be unusually problematic.