Maryland and federal health
officials will converge on Takoma Park Elementary School next week to
find out why at least 12 students
contracted chickenpox in the past two
months despite receiving vaccinations against the disease.
Of the 16
cases of chickenpox tallied so far at the Montgomery County
school, all but four
involved youngsters who reportedly received the vaccine
before they were 3 years old.
Physicians are not required
to report chickenpox to government agencies, and it isn't clear whether
the number of cases logged at the school so far is accurate -- especially
because some cases are so mild that parents aren't aware of them.
Officials with the Montgomery
County Department of Health and Human Services, the state Department of
Health and Mental Hygiene and the U.S. Centers for Disease Control and
Prevention will use a survey to nail down the numbers and help whether
the vaccine has failed in some way.
Jane Seward, acting chief of
CDC's child vaccine and preventable diseases branch, said she is not alarmed
by Takoma Park Elementary's outbreak.
It is possible the high percentage
of cases among reportedly vaccinated children merely reflects the
Maryland chickenpox vaccination rate, one of the highest in the nation,
she said.
"That's what you start
to see when a state achieves a high coverage rate for a vaccine,"
she said. In 1999, 78.5 percent
of Maryland children in the target age
group were vaccinated, the third-best performance of any state,
she said.
Since chickenpox vaccine was
licensed in 1995, its use has grown steadily, she said. Doctors
never expected it to wipe out the illness; instead the vaccine
is supposed to prevent chickenpox in 80 to 85 percent of those who receive
it and prevent severe cases from developing in the rest, she said.
Severe cases bring hundreds
of painful blisters, high fever, excruciating itchiness, possible infection
caused by scratching, and decreased appetite caused by sores in the mouth.
In extreme cases, patients
can develop pneumonia, brain infection or bleeding disorders, Seward said.
CDC says more than 5,000 people are hospitalized and about 100 die of
chickenpox nationwide each year.
