Mumps in Atlantic Canada

From the office of the Medical Health Officer

Mumps in Atlantic Canada | Pertussis Risk to Infants | Preventing Infectious Disease through Breastfeeding

The Nova Scotia / New Brunswick mumps outbreak, affecting mainly those in their early 20’s, continues to spread. If you see a patient with sialadenitis, particularly parotitis, who has a Maritimes connection, collect urine and a viral throat swab for mumps virus testing. Please phone the health unit whenever you suspect mumps (numbers below) and tell patients to avoid exposing others. 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. The incubation period is 14-25 days (usually 16-18). To diagnose mumps, order mumps IgM to be taken no sooner than the 4th day after onset of salivary gland swelling. (IgM must be specified or the lab will measure total immunoglobulins and won’t check for acute disease.) In BC, 2 doses of MMR vaccine are provided free to those ?18 years old. A second dose of MMR is also recommended but not provided free for travellers >18 years old born after 1956.

INFANTS VULNERABLE TO PERTUSSIS FROM PARENTS AND SIBLINGS

Whooping cough in young infants can be serious and sometimes fatal. A recent study (1) found that for infants in whom a source case could be identified, household members and especially parents were responsible for 76-83% of transmission. Adults can transmit pertussis even without having symptoms themselves. It is crucial to suspect pertussis and do a nasopharyngeal swab for PCR and culture, especially when there are close contacts who are pregnant women or infants, for whom antibiotic prophylaxis is recommended regardless of vaccination status.
Suspect pertussis when a patient feels reasonably well between suffocating coughing fits triggered by talking or laughing, and worse at night. Whooping may not be present in teens and adults, although the cough can still be severe enough to lead to post-tussive vomiting, cyanosis, broken ribs, hernias, etc. Pertussis is contagious until 21 days after cough onset, with an incubation period of 6-21 (average 7-10) days. Antibiotics stop infectivity after 3-5 days, but once paroxysmal cough starts it persists for weeks with or without antibiotics. Transmission can occur with five minutes of face-to-face contact or an hour of sharing a room with someone who has pertussis. Protect yourself and other patients by asking coughing patients in your office to wear a surgical mask.

Pertussis vaccine protects against both symptoms and infectivity. Adacel®, which also prevents diphtheria and tetanus, is provided free to Grade 9 students, those aged 7-18 years who need a booster, and those 7 and older with no previous tetanus-diphtheria immunization or who have immigrated with unknown immunization status. NACI recommends that adults up to age 64 years who need a tetanus booster and have not yet had acellular pertussis vaccine receive a single dose of Adacel, which they must purchase (~$40; prescription not needed.)

1. Wendelboe AM et al. Transmission of Bordetella pertussis to Young Infants. Ped Infect Dis J. 2007; 26(4):293-299

BREASTFEEDING PROTECTS INFANTS AGAINST SEVERE INFECTIOUS DISEASE

Formula lacks anti-infective factors found in human breastmilk. Recent studies in developed nations show that breastfed babies are at lower risk of post-neonatal death (1) and of hospitalization for infectious disease. (2, 3) Breastmilk-derived protection is especially important for babies too young to be immunized.

1. Chen A, Rogan WJ. Breastfeeding and the Risk of Postneonatal Death in the United States Ped 2004; 113(5): e435-e439
2. Talayero J-M P et al. Full Breastfeeding and Hospitalization as a Result of Infections in the First Year of Life (Spain) Ped 2006 118(1):e92-e99
   A study of 1385 infants found that 30% of hospital admissions could be avoided for each month of full breastfeeding. Fully breastfeeding to 4 months would avoid 56% of hospital admissions of infants <1 year old.
3. Quigley MA et al. Breastfeeding and Hospitalization for Diarrheal and Respiratory Infection in the UK Millennium Cohort Study Ped 2007; 119(4):e837-e842 A population-based study of 15890 healthy infants born 2000-02 estimated that exclusive breastfeeding could prevent 53% of diarrhea hospitalizations and 27% of lower respiratory tract hospitalizations per month; partial breastfeeding would prevent 31% of diarrhea and 25% of lower respiratory tract hospitalizations.