The state of Massachusetts has seen 30 mumps cases so far in 2016 and more than half have been in Harvard University students. Through Mar.22, 16 mumps cases have been confirmed among Harvard students.
Mumps virus is spread through infected respiratory tract secretions. It can be spread within three to six feet when an infected person coughs or sneezes, or with direct contact with infected secretions (e.g. sharing water bottles). The incubation period can range from 12 to 25 days. Parotitis (swelling of the salivary glands) is the most common symptom (30-65%), but non‐specific symptoms such as myalgia, anorexia, malaise, headache, and low‐grade fever may precede the parotitis by several days. In the prevaccine era, 15-30% of infections were asymptomatic.
Mumps is usually a mild illness, but there can be complications including meningitis, encephalitis, orchitis, oophoritis, mastitis, glomerulonephritis, myocarditis, arthritis, and hearing loss. People are considered infectious from two days before symptoms begin until five days after the onset of parotid swelling. Therefore, those suspected of mumps should be isolated and should refrain from public activities for five days after the onset of swelling.
Mumps vaccine is highly effective in preventing mumps. One dose is 78% effective, and two doses are 88% effective. Protection appears to be long lasting; however immunity may wane and mumps cases do occur in vaccinated individuals.