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In the last 20 years, the number
of cases of whooping cough increased overall in the US according to the
US Centers for Disease Control and Prevention (CDC).
Whooping cough, or pertussis,
is caused by infection
with the Bordetella pertussis bacterium. Symptoms of whooping
cough include having a cough lasting 14 or more days accompanied by a
gasping sound or "whoop" while coughing. Children may also vomit
or have difficulty breathing during a coughing spell.
The number of pertussis cases
has remained stable among children old enough to be vaccinated, but the
increase in cases in children younger than 6 months indicates that "a
true increase in pertussis circulation" has occurred.
From 1997 to 2000, over 7,000
pertussis cases among all age groups were reported each year in the US,
compared with about 2,000 cases per year in the early 1980s.
Pertussis remains an endemic
disease. Adolescents and adults likely play an important role in transmitting
pertussis to very young infants.
Among the 29,000 persons with
pertussis from 1997 to 2000 for whom ages were known, 29% were aged less
than 1 year, 12% were aged 1 to 4 years, 10% were aged 5 to 9 years, 29%
were aged 10 to 19 and 20% were 20 years or older.
Additional data collected by
the National Health Interview Survey in 1998 suggest that 73% of children
aged 7 to 18 months were vaccinated with three or more doses of acellular
pertussis (DTaP), diphtheria and tetanus toxoids (DTP), or diphtheria
tetanus toxoids (DT) vaccines.
Vaccine effectiveness
was estimated at 88% in
children aged 7 to 18 months, with approximately two thirds of the vaccinations
being DTaP and one third being DTP.
Morbidity and Mortality
Weekly Report February 1, 2002;51:73-76
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