More than 23,000 cheerleaders from 39 states and eight other countries have been exposed to mumps at a competition in Dallas, health officials have warned.
Families of the nation’s top teams received an alarming letter on Friday urging them to get tested for the virus just nine days after the national championship final.
Around 2,600 coaches have also been urged to seek medical help.
Health officials warn the virus is incredibly infectious, and though often easy-to-miss it can lead to deafness or swelling of the brain in extreme cases.
The nation’s top cheerleaders received an alarming letter on Friday urging them to get tested for the virus just nine days after the national championship final (file image of the contest)
‘If you, your child, or any other individuals linked to this event experience or have experienced mumps symptoms, please contact your health care provider and inform them of your exposure to mumps,’ the department wrote in a letter to parents last week.
It is not clear what led to the warning, which comes amid a resurgence in cases among vaccinated communities.
Despite years of plummeting rates, the CDC warned in November that the tide started to turn in 2010.
Before the vaccine was rolled out in the US in 1967, the virus of the salivary gland, spread by saliva or mucus through coughing and sneezing, was a common infection among children, and led to hundreds of deaths.
The rate of infection plummeted down to a couple of hundred a year by the 1980s and continued that way until around 2010.
But last year, the CDC recorded more than 6,000 mumps infections, particularly driven by clusters of outbreaks, many of which are on college campuses and sports teams.
Experts warn that this is driven by a few key factors.
First, immunity wanes over time, and most people get their second MMR dose before the age of six, which is a long time ago for students reaching college.
Second, the higher-than-usual exchange of bodily fluids through drinks or contact among close-knit groups such as students and athletes.
Third, a waning sense of urgency to vaccinate children against the now-distant threat of mumps which plagued baby boomers and the silent generation weakening our ‘herd immunity’.
For decades, the CDC has advised children get two doses of the MMR vaccine – their first at around one year old, and their second between four and six years old – which gives a child about 88 percent protection against mumps, measles and rubella.
‘That’s high but not 100 percent,’ warns Dr Pritish Tosh, MD, an infectious diseases specialist at the Mayo Clinic, told Daily Mail Online.
According to Dr Tosh, the strength of the vaccine partly relies on ‘herd immunity’, requiring that the vast majority of each community (at least 90 percent) is protected.
‘When you have some people who are unvaccinated or under vaccinated in a community then we lose some of that herd immunity meaning the populations can be at-risk of infection, even if they were vaccinated.
‘Once you start dropping in that number, you run a risk of re-introducing mumps into a population.
‘Certainly, unvaccinated people get sick but also there will likely be vaccinated people who get sick because the vaccine is not 100 percent effective.’
He warns: ‘The unvaccinated people are amplifying the outbreak then allowing some who are unvaccinated to become sick. This has been seen more and more including in college campuses.’