Scarlet fever nursery grandparents

I work for the Health Protection Agency. I was due to phone a nursery to advise about scarlet fever when i received a call about scarlet fever in another nursery. The nursery assisstant i spoke to had the same surname as the child with scarlet fever she was enquiring about. I pointed this out and she said that it was actually her grandson. Immediately afterwards i phoned the other nursery and spoke to the nursery assistant about a child with scarlet fever...different surnames but the lady voluntarily told me it was her grandaughter. We have the data on total scarlet fever calls received per year in nurseries and peak call dates. You could probably estimate % of nursery assistants who are granparents of children attending. To receive two on the same day within minutes of each other when the key detail about the grandparent connection was revealed is wonderfully coincidental.