Update on Mumps in Fraser East

In addition to the outbreak of mumps in Chilliwack, sporadic cases of mumps are being seen in Abbotsford, Agassiz and Mission. Some of the people with lab-confirmed mumps live in town and some in rural areas. Some have had contact with people with mumps and some – as far as they know – haven’t.

If you see patients with siladenitis (parotid, submandibular, or sublingual) or orchitis, 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. Mumps infection is asymptomatic (but infectious) in roughly 1/3 of cases and causes only URTI symptoms in another ~1/3 – so always give coughing patients a mask when they arrive at your office. Mumps can also cause mastitis and/or oophoritis, pancreatitis, thyroiditis, arthritis, meningoencephalitis, and first-trimester miscarriage (but not congenital malformation).

If you suspect mumps:

1. BUCCAL SWAB: Take a buccal swab at Stenson's duct above the 2nd molar (strip the parotid first if it's not too sore) for mumps PCR using a viral swab kit. Keep samples in the fridge, then ship together with a wrapped-up ice pack to the lab. 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 those with partial immunity.
2. URINE SAMPLE: Collect a urine sample for mumps PCR in a sterile culture container. Mark the requisition “MUMPS OUTBREAK” in BIG letters.
3. SEROLOGY: Order acute mumps IgM and IgG at 3-5 days after onset of prodromal symptoms. Also order convalescent serology at 10 days - 3 weeks from onset of symptoms. Mark the requisition “MUMPS OUTBREAK” in BIG letters. For patients going to the lab within 9 days of onset of parotitis, please alert the lab and give any coughing patient a surgical mask to wear. With no mumps immunity, IgM is present by day 5 from symptom onset, peaks ~1 week, and lasts from 6-12 months. With partial immunity, IgM may not be seen and IgG will rise soon after exposure and may already be high by the time acute serology is drawn.
4. Tell the patient to stay home, stay 1 metre away from others, and avoid saliva sharing (coughing into the air, kissing, sharing drinks, etc.) until 9 days after onset of salivary gland swelling (or if there is no siladenitis, until 14 days after onset of first symptoms).
5. Alert your Health Unit (phone numbers below) to expedite lab tests and follow up contacts.

The infectious period for mumps is from 7 days before to 9 days after parotitis onset, with maximal infectivity from 2 days before to 5 days after. Spread is by respiratory droplets and saliva-sharing.

For copies of previous mumps information sent to physicians (February 22 and March 10, 2008) or to download a copy of the poster “If you think you might have mumps” call the local Health Unit.