Festival-goers have been warned that that they risk picking up a case of the measles as an unwanted souvenir unless they ensure their vaccinations are up to date.
Public Health England said that dozens of cases of the viral illness have been linked to arts and music events in June and July this year alone.
It added that large events where people are in close proximity to one another "provide the ideal place for the infection to spread".
Measles infections linked to festivals this summer include:
- Glastonbury - 16 cases
- NASS - seven cases
- Triplicity Music and Arts festival - six cases
- Tewkesbury Medieval Festival - three cases
- Nozstock: The HiddenValley - two cases
- Noisily - two cases
- Secret Garden Party - one case
- Yeovil Show - one case
The health body has urged people attending festivals to check their vaccination record and get the MMR injection if they are not already protected.
Anyone who thinks they may have the infection should not attend upcoming events as they may pass it on, it added.
Dr Mary Ramsay, head of immunisation at PHE, said: "Measles is a highly infectious viral illness that can be very unpleasant and sometimes lead to serious complications.