It's time for a mumps outbreak! Here is a basic primer on the very basic basics.

How do you get mumps? 

• Respiratory secretions, that guy sitting next to you on the airplane with the huge parotid gland and just sneeze in your eye. Not good.

Incubation period

• How long does this need to cook before mumps is ready for full star spangled disease manifestation? Somewhere between 2-3 weeks.

Presentation

• The classic presentation is a swollen parotid gland. Usually it’s both, but in a quarter of patients, it’s unilateral parotitis, which can make things tricky when you’re wondering if this patient has acute bacterial parotitis, or mumps. The other salivary glands can swell as well, but much less commonly than the parotid. 
• All this salivary swelling business may be preceded by a few days of viral syndrome fever , headache, body aches, feeling crappy.  Patients feel bad for a few days, the parotids swell, stay swollen for anywhere from 2  to 10 days. There may, however, be no parotid swelling as well, just a viral syndrome and nothing else (there may also be no symptoms). 

The other issues with mumps

Orchitis. Can be one testicle, can be  both testicles. Females can also have reproductive organ involvements- less than 1% with oophoritis and a similar rate for mastitis. Non reprotrducgei or salivary gland involvement include aseptic meningitis and pancreatitis.

But wait, I can’t get mumps, I’ve been vaccinated. 

• Unfortunately that’s not 100% protective and sadly, immunity can wane. 

Treatment

• There is no specific treatment, just supportive care.

Your job 

• Your job now is to keep it from spreading. In the hospital, droplet precautions. Mumps is most infectious from 2 days before the parotid swelling to at least 5 days after. Hard to quarantine when there's no parotid swelling, but once it starts, 5 days of no school, no work, and separated from family members (not always possible).

Testing

• We’re getting these recommendations from the health department to collect samples from almost every body fluid, but isn’t blood enough? It turns out that it is not. Serum IGM, which you’d expect to see in an acute infection, may be falsely negative, especially in someone who has been vaccinated. Many different tissues are infected in mumps, so to really figure out if it’s mumps or not, we’ve been advised to get serum, urine, and buccal swabs. By the time the results come back, your patient will probably be finished with quarantine, but from a public health angle, you’re a hero.

Testing advanced level 

• In unvaccinated patients, IgM is present by day 5 post onset of symptoms. In a vaccinated person, there might not be any IgM and it could have a very quick spike and disappearance. When you get that IgM mumps test back negative 3 weeks after you’ve seen the patient,  just know that that doesn’t mean they don’t or didn't have mumps. 
• Why buccal swabs? This tests for the mumps virus itself and is very good in the early stage of infection, especially in someone who has had vaccination, which is hopefully everybody, but it’s not. 
• Why urine testing? Not as sensitive as buccal testing in early infection but currently recommended in our region. I’m guessing to cast as wide a net as possible. 

Call the health department

• Initiate patient tracking, contact tracking, and have a public health expert take over with following up on test results etc. 

Bottom Line

• If you see a patient with parotid swelling and there has been a viral prodrome, or perhaps there’s been a mumps outbreak - think mumps. If you have high suspicion, immediately  initiate droplet precautions, collect samples, call the health department, quarantine (at home) and if possible separate from family for 5 days following onset of parotid swelling. Sometimes that last part is not possible, but have them do their best.

Links

• Specimen Collection (what to order, exact way to collect it). Link
• Oregon Public Health Mumps Review (mumps overview). Link
• Oregon Public Health Mumps Main Page (investigative guidelines, case report form). Link
• CDC Mumps Pinkbook Review (mumps overview) Link
• CDC Mumps mainpage Link
• CDC Current Mumps Outbreaks Link