The recent outbreak of mumps on the US east coast has been traced to an 11-year-old boy who visited Great Britain, reports the CDC.
The boy reportedly returned from the trip on June 17, 2009. UK health authorities reported approximately 7,400 cases of laboratory-confirmed mumps in 2009. The boy then attended a summer camp for tradition-observant Jewish boys in New York, where he infected other campers and staff members. By Jan. 17 of this year, 1,521 cases of mumps were reported.
The outbreak has remained confined primarily to the tradition-observant Jewish community, with less than three percent of cases occurring among persons outside the community. Nearly half the cases were in New York City, primarily Brooklyn.
England suffered a outbreaks of measles and mumps following Dr. Andrew Wakefield’s now discredited paper in The Lancet. Britain’s General Medical Council recently found Wakefield guilty on 30 counts of unprofessional conduct in connection with that paper, and the journal recently retracted the paper. The paper hypothesized a link between the MMR vaccine and autism. Despite the total lack of credible evidence, Wakefield suggested that worried parents should break up the vaccine into three separate shots to avoid injury. That comment set off a panic that saw MMR uptake plunge to 50% in some parts of the UK.
The mumps component of the MMR vaccine provides less protection than the measles or rubella components. The CDC estimates a mumps-vaccine efficacy of 73%-91% after 1 dose and 79%-95% after 2 doses.
Of those infected in this outbreak, 88 percent had received at least dose of MMR, and 75% had received two. Health officials aren’t taking any chances:
Beginning on January 19, 2010, in Orange County, New York, public health officials began offering a third dose of MMR vaccine in three schools where, despite documentation of a high level of 2-dose coverage among students, transmission had continued for >2 months. This intervention is being carried out under an Institutional Review Board–approved protocol that provides for an evaluation of the impact of the intervention.
One of the most common symptoms of mumps among boys is orchitis, or testicular inflammation, which can lead to sterility. In the latest outbreak, 76% of the victims were male. The median age of those infected is 15 years.