However, I do believe all primary school teachers have received training in dealing with diabetics, epileptics and other vulnerable young folk.
What a teacher is taught about illnesses/first aid will depend upon when and where they trained and whether they've encountered children with these illnesses subsequently.
For myself, back in the dark ages of the 70s there was none. I had a child with diabetes on my final teaching practice and vaguely knew about hypos from general knowledge, but whether I would have recognised one, I really don't know. As it was the child was rarely in school.
After that the small number of pupils with diabetes I came in contact with were on insulin regimes that did not require injections at school, none brought a glucose monitor to school. Most members of staff would be told about the child and some general info given at a staff meeting, but to be honest it is sometimes hard to remember who has what if you don't come into contact with the child on a normal basis. If the child was in your class then you would know a bit more, usually guidance on PE, mealtimes and snacks , ( as an aside, whilst the majority of parents are very involved and keep schools fully informed about medical conditions or events that might affect a child's education, there are a number that don't)
Recently with multiple injections, insulin pumps and more frequent testing more detailed knowledge is needed. Individual teachers/support assistants who agree to adminster/supervise injections and testing receive training from medical personel. However, teachers in general, particularly in small primary schools, probably encounter very few children with diabetes in their career so their knowledge will be variable and may be very outdated. Hence the need for INSET when the need arises.(not always easy to put in place at short notice, so if a child develops diabetes some info might still just form part of a general staff meeting)
This is a quite a detailed leaflet written for teachers from the NUT. The section 'Action Points for NUT Safety Representatives' a describes what a school should be doing to raise the awareness of all members of staff and ensure the safety of pupils with diabetes.
http://www.teachers.org.uk/node/379