The mumps outbreak in Harvard University started over two months ago. In February, the institution announced the first two cases of mumps infection, but the contagious disease continued to spread and infected at least 40 students despite prevention and isolation efforts. Many of those infected with mumps are vaccinated.

The increasing number of students being infected with mumps is worrying health officials. Paul J. Barreira, director of the university's health service,s told the school paper that if the mumps infection trend increases this week the outbreak could interfere with Harvard University's commencement exercise on May 26. Those who get infected are isolated to prevent the spread of the highly contagious disease, CNN reports.

The number of #Harvard mumps cases has spiked from a post-spring break low of two cases to 40 cases, as of Monday. https://t.co/s3mTdvkDUE

— The Harvard Crimson (@thecrimson) April 26, 2016

All Harvard students infected with mumps have been vaccinated. UPI notes that before they are admitted to the university, all new students must have MMRV (measles, mumps and rubella) immunization. More than ten students are in isolation since Monday. Barreira adds that the increasing incidence of mumps infection in Harvard University is also due to students not taking important precautions to not spread and get infection with the disease.

Susan Feinberg of the Cambridge Public Health Department told ABC News that college campuses are a dangerous breeding ground for infectious diseases like mumps. She further explained that because students are in close proximity with others and sharing things will make the spread of the disease more likely.

Mumps is a viral disease that causes inflammation of the salivary glands. The most common symptoms of mumps infection include headache, fever, muscle aches, tiredness, appetite loss and the appearance of swollen jaws caused by the inflamed salivary glands under the ears. The Centers for Disease Control and Prevention shares that mumps is spread through saliva or mucus. People can get infected through coughing, talking, sneezing, sharing eating utensils and touching infected surfaces.