British Columbia measles outbreak spreads
A measles outbreak in the Fraser Valley east of Vancouver has temporarily closed a school in eastern British Columbia after sickening nearly 100 students, and vaccine is being distributed to pharmacies and physicians' offices as the outbreak spreads from the school into the nearby communities, according to news sources this week.
The outbreak began at the Mount Cheam Christian School in the town of Chilliwack, said a Mar 11 Toronto Star story. Two cases in the greater community had been confirmed at that time, but a CBC News story today says 80 new cases have been reported from Chilliwack and nearby Agassiz. One patient, a 9-year-old girl, has been hospitalized.
British Columbia's Fraser Health system is requesting that older children and adults in its Fraser East region (which includes the communities of Abbotsford, Mission, Harrison Hot Springs, and Hope in addition to Chilliwack and Agassiz) get vaccinated with the two-dose series, according to a news story from the organization. Children under age 5, who are at greatest risk from measles, need to obtain vaccinations through a physician's office or public health clinic, says Fraser.
The Star story says the students at the school had a low vaccination rate because of religious beliefs, but of even more concern is the 25% to 30% of people in the surrounding communities who have not been vaccinated even though the vaccine is available and free.
Fraser is organizing vaccination clinics in Chilliwack and Agassiz for next week. In addition, people are being asked to isolate themselves at home if they have measles symptoms (blotchy rash, high fever, runny nose, cough), to avoid travel during spring break if they think they may have been exposed, and to alert any healthcare facility they plan to visit.
Mar 14 CBC News story
Mar 13 Fraser Health news story
Mar 11 Toronto Star report
In related news, California is reporting 32 cases of measles since the beginning of the year, according to a news release today from the California Department of Public Health (CDPH). Last year at this time, only 3 cases had been reported.
Vaccination coverage in the state is high; 10 of the cases reported this year have been in people who have traveled to other countries where measles outbreaks are ongoing or where it is endemic (Philippines, India, and Vietnam).
Mar 14 CDPH news release
More measles cases confirmed on Mediterranean cruise ship
Italian and European health officials yesterday in Eurosurveillance said 15 more cases of measles have been confirmed aboard a Mediterranean cruise ship that has posed a cross-border health threat. The outbreak was originally announced in a Mar 5 risk assessment from the European Centre for Disease Prevention and Control (ECDC).
As of Mar 11, 27 measles cases have been reported, 21 of them in crew members and 4 in passengers. The crew or passenger status couldn't be determined for two of the patients. Of the total, 22 cases were lab-confirmed and 5 were classified as probable. In its Mar 5 risk assessment, the ECDC had said 7 cases were confirmed at that point.
Ages range from 1 year to 42 years, and 21 of the case-patients are male. Home countries were known for 19 of the patients and included Italy, India, Philippines, Honduras, Austria, Brazil, and Indonesia.
Of 12 cases in which vaccination history was available, 3 patients were vaccinated with one or two doses and 9 were unvaccinated. Among samples obtained from 22 patients, measles genotype B3 was found in 10 and the samples were 100% identical to each other, suggesting a common origin; the strain was related to two British strains identified in February.
Illness onset ranged from Feb 20 through Mar 1. European countries received lists of passenger names and passport numbers for those who were aboard the cruise, but in some instances there wasn't enough contact information to track some of travelers.
On Feb 27 the ship's medical team launched a vaccination campaign for crew and passengers who had no evidence or prior immunity. The ship is also offering vaccination to new crew members who arrive on board.
The authors of the report said measles aboard a cruise ship presents many challenges, including a large number of people in close quarters with unknown vaccination status. They noted that no new infections have been seen in the crew since Feb 27, but some may already have been incubating measles when they were vaccinated. The number of infected passengers may be underestimated, because the average time spend on board wasn't long enough for an exposed patient to develop symptoms.
Mar 13 Eurosurveill report
Mar 5 CIDRAP News story "ECDC reports measles outbreak on cruise ship"
Study: Pertussis vaccine linked to fewer hospitalizations
Even though a high proportion of breakthrough pertussis cases occur in people vaccinated for the disease, immunization does result in decreased morbidity, including hospitalizations, according to a study today in Clinical Infectious Diseases.
The authors analyzed the records for 624 children in the Portland, Ore., area aged 6 weeks to 18 years with confirmed pertussis from 2010 to 2012 to determine vaccination status and disease severity and duration. They found that 286 (45%) patients were up to date with federal vaccination recommendations and 167 (27%) had received one or more vaccinations but were not up to date.
Ever-vaccinated patients had significantly lower risks of hospitalization and of severe disease than unvaccinated patients. They also had decreased odds of hospitalization and of developing pneumonia compared with those unvaccinated.
Furthermore, patients who were up to date with federal recommendations had a significantly shorter duration of coughing, a measure of disease severity.
An accompanying commentary stressed the need for a new pertussis vaccine since the current ones allow so many breakthrough infections. However, it concludes, "The current vaccines, even with the limitations, are still protective and reduce the severity of pertussis."
Mar 14 Clin Infec Dis study abstract
Mar 14 Clin Infec Dis commentary landing page
