Visitors to Kettering General Hospital have been warned about exposure to a case of measles.
A patient with the highly contagious disease attended the hospital's Centenary Wing between 1pm and 5.30pm on September 23, it has been confirmed.
The disease is airborne and spreads easily through the coughs and sneezes of infected people.
Initial symptoms typically include a fever, cough, runny nose and inflamed eyes and small white spots can form inside the mouth two or three days after the start of symptoms.
A red rash can start on the face and then spread to the rest of the body, usually three to five days after the start of symptoms.
It can be serious, particularly for those whose immune system is not working normally or those who have not had their MMR jab.
Public Health England (PHE) confirmed there are currently sporadic measles cases in the East Midlands.
Dr Samia Latif, consultant in communicable disease control at PHE East Midlands, said: “Measles is an unpleasant disease and spreads very easily amongst anyone who has not had two doses of MMR.
"It is important that anyone who hasn’t already had two doses of the MMR vaccine, regardless of their age, contacts their GP surgery for an appointment to get vaccinated.
“Measles typically starts with cold-like symptoms accompanied by sore red eyes, a high temperature and a red-brown blotchy rash.
"If you experience these symptoms, please stay at home and phone your GP or NHS 111 for advice, rather than visiting the surgery or A&E, to prevent others from being infected.”
A KGH spokesman said it was a matter for PHE to comment on.