Mumps Activity in All Fraser Health

We have now seen lab-confirmed mumps in Hope, Agassiz, Chilliwack, Abbotsford, Mission, Langley, Surrey, Maple Ridge, and Burnaby. Because immunity against mumps wanes, neither remote history of vaccination or having had mumps rules out mumps in a patient with mumps-like illness, although it makes it less likely.

People who are partially immune and become infected with mumps are more likely to be asymptomatic or have just URTI symptoms – but they still shed virus and can infect others. Patients with mumps may thus have no idea how they were exposed to the mumps virus.

If you see patients with sialadenitis (parotid, submandibular, or sublingual) or orchitis or oophoritis, please test for mumps. Also think of mumps in anyone who has been in contact with mumps then presents 12-25 (usually 16-18) days later with URTI symptoms. Because mumps infection can cause URTI symptoms – and is spread through saliva and respiratory droplets - always give coughing patients a mask when they arrive at your office. Mumps can also cause mastitis, pancreatitis, thyroiditis, arthritis, meningoencephalitis, and first-trimester miscarriage (but not congenital malformation.)

If you suspect mumps, please do the following:

1. BUCCAL SWAB for mumps PCR: Take a buccal swab at Stenson's duct above the 2nd molar (strip the parotid first if it's not too sore) using viral swab kit #1811 (the same as for varicella, herpes, etc.).
   URINE SAMPLE for mumps PCR: Collect in a sterile culture container.
   Keep samples in the fridge, then ship to the lab together with a wrapped-up ice pack. Mark the requisition “MUMPS OUTBREAK” in BIG letters. PCR may be positive in non-immune patients up to 9 days after onset of symptoms, but may go negative earlier in the partially immune.
2. SEROLOGY: Order acute mumps IgM and IgG at 3-5 days after prodrome onset. For classic mumps symptoms, if IgM is negative and IgG positive, order convalescent IgG from 10 - 21 days after initial serology was drawn. Mark the requisition “MUMPS OUTBREAK” in BIG letters. For patients going to the lab within 9 days of parotitis onset, please alert the lab and give any coughing patient a surgical mask to wear. With no prior immunity, IgM is present by day 5 from symptom onset, peaks ~1 week, and lasts 6-12 months or, rarely, even longer. With partial immunity, IgM may not be seen and IgG rises soon after exposure, so IgG may already be high when acute serology is drawn.
3. Tell the patient to stay home, stay 1 metre away from others, and avoid kissing, sharing drinks, coughing into the air, etc. until 9 days after sialadenitis onset (or if no sialadenitis, until 14 days after onset of first symptoms). Mumps spreads by respiratory droplets and saliva-sharing.
4. Alert your Health Unit (phone numbers below) to expedite lab tests and follow up contacts.

Consider mumps infectious from 2-4 days before prodrome onset OR 7 days before parotitis onset, until 9 days after parotitis onset. Infectivity is highest from 2 days before to 5 days after parotitis onset.