Abington School District administrators say they have been dealing with an unexpectedly large number of pertussis cases this school year. Most unusual, according to health officials, is that the district had not experienced an outbreak before.
Pertussis, also known as whooping cough, tends to run in cycles, and this year's incidence is not unusual at the national, state, and county levels.
The 56 cases in Montgomery County since Jan. 1 are "pretty routine," said Frank X. Custer, a spokesman for the county. Also routine: Every one of the recent whooping cough patients had been vaccinated.
The vaccine simply "is not nearly as good as people thought it was," said Stephen Gluckman, an infectious diseases physician at a University of Pennsylvania primary care clinic. Multiple studies have found effectiveness declining within a few years, sometimes to as low as 30 percent.
The other two components of the combined diphtheria, tetanus, and pertussis vaccination (DTap for infants and a Tdap booster for adolescents and adults) are far more effective.
The pertussis part was reformulated in the 1990s to lessen side effects, and the waning protection was not fully realized until years afterward. Still, health officials say, vaccinated individuals who come down with the disease tend to suffer lighter symptoms than the unvaccinated.
Pertussis also often goes unrecognized, Gluckman said, because its initial symptoms look like a cold. The telltale paroxysms of coughing - the "whooping" sound - come later, well into the infectious phase.
The biggest U.S. outbreak in recent years was in 2012 - Montgomery County had 254 cases that year, Pennsylvania reported 1,945, and New Jersey had 1,395. Nationally, there were more than 48,000.
But Abington district officials said their students have had more cases this year. The district has reported 16 cases since September, according to the county Health Department. More than half the county's districts have had cases, with another large one, Lower Merion, reporting 12.
School districts report cases by academic year, while county, state, and federal data are for the calendar year. But most Abington cases have come since Jan. 1. Some were in clusters - siblings or children who shared a car pool - but only one involved two children who were in the same classroom, said Judy Bomze, the district's director of pupil services.
The number went up just from Friday to Monday, Bomze said. Each case generates a phone call and letter to parents with children in the building.
Back-to-back notifications "can create some concern," Assistant Superintendent Jeffrey Fecher said. But he said that no parents, including those whose children who cannot be vaccinated because of weakened immune systems, have kept their children out of school as a result. None of the immunocompromised children have been infected.
Standard practice is to keep children thought to have pertussis at home for five days. The district has stepped up cleaning at schools, and staff are on alert for respiratory symptoms.
Pertussis is uncomfortable, but the main danger is for babies too young to be immunized. Their coughing spasms can be so severe that they can't breathe and sometimes they can have bleeding into the brain, Gluckman said.
That's why grandparents have been encouraged in recent years to get a booster.