Three Suspect Mumps Cases in Chilliwack

PLEASE LET YOUR HEALTH UNIT KNOW IF YOU SUSPECT A PATIENT MAY HAVE MUMPS

Parts of Alberta have had a mumps outbreak for the past 5 months. Now three Chilliwack students have come down with mumps-like illness after contact with Alberta visitors who also had mumps-like illness.

Therefore, stock up with ice packs, give coughing patients a surgical mask when they arrive, and if you see a patient with sialadenitis, particularly parotitis:

1. Ask about travel or exposure to travellers or to anyone with mumps or mumps-like illness.
2. 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 the sample in the fridge, then wrap it up with an ice pack for transfer to the lab. Mark the requisition “FOR MUMPS VIRUS ISOLATION” in BIG letters. PCR may be positive in non-immune patients up to 9 days after onset of symptoms, but may go negative much earlier in patients with partial immunity.
3. Order acute IgM and IgG to be done 3-5 days after onset of prodromal symptoms to be sent EMERGENT to the BCCDC laboratory. Also order convalescent serology to be done 10 days - 3 weeks from onset of symptoms. Mark the requisition “SUSPECT MUMPS” in BIG letters. For patients going to the lab within 9 days of onset of parotitis, please alert the lab and provide coughing patients with a surgical mask to wear.
   
   With no immunity to mumps, IgM is present by day 5 from symptom onset, peaks ~1 week, and lasts at least 6 weeks. With pre-existing immunity, IgM response is highly variable or absent, while IgG begins to rise soon after exposure and may already be high when acute serology is drawn.
4. Tell the patient to isolate him/herself, 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.
5. Alert your local public health unit to expedite lab tests and follow up contacts.

Mumps is infectious from 7 days before to 9 days after parotitis onset, and most contagious from 2 days before to 4 days after onset of illness. Spread is via saliva-sharing as well as by respiratory droplets and airborne transmission. The incubation period for mumps is 14-25 days (usually 16-18).

MMR AND OTHER MUMPS-CONTAINING VACCINE: ARE YOU IMMUNE TO MUMPS?

In BC, 2 doses of MMR are provided free to: those ?18 years old, women of childbearing age susceptible to rubella, health and child care workers born after 1956, military recruits, and post-secondary students. Vaccination is 80% effective after one dose and 90-95% after two doses, although protection may be less in the outbreak setting: e.g., 64% and 88% for one vs. two doses respectively in a 1998 UK outbreak (Harling 2005).

BCCDC advises that health care workers (including physicians) exposed to a case of mumps:

• with 2 documented doses of mumps-containing vaccine, can continue to work
• with 1 documented dose of mumps vaccine, can return to work right after receiving a dose of MMR
• if no documented mumps vaccine, can return to work once mumps IgG is shown to be positive
• if mumps IgG unknown or negative, off work from 10th day after first exposure until 26th day after last exposure to mumps (inclusive)

ABOUT MUMPS: Mumps causes siladenitis, usually of one or both parotids, with (usually mild) pancreatitis in ~4%. About 1/3 of mumps infections present as respiratory tract infections without siladenitis. Infection is more likely to be severe in adults and be milder in the previously vaccinated. Sensorineural hearing loss is a rare complication in both children and adults. Meningoencephalitis occurs in ~250 per 100 000 cases, with a mortality of about 2%. Up to 38% of postpubertal men with mumps develop orchitis, with ~13% of these having reduced fertility. Mumps in the first trimester of pregnancy is linked to an increased rate of spontaneous abortion but not congenital malformation. Treatment is symptomatic.