CincinnatióMost people already know that whooping cough is a serious
disease that can be prevented with a series of regular childhood
vaccinations. But many are unaware that even though they were
vaccinated as a child they can still become infected with the pertussis
bacteria as an adult. Worst yet, whooping cough can be carried by
adults and spread to infants because the vaccine does not provide a
lifetime of immunity.
Alison Weiss, PhD, a University of
Cincinnati (UC) Medical Center associate professor of microbiology, has
studied the pertussis bacterium, Bordetella pertussis,
for 20 years. She and Beverly Connelly, MD, associate professor of
pediatrics/infectious diseases (ID) at the UC College of Medicine and
the director of the Pediatric ID fellowship program at the Cincinnati
Children's Hospital Medical Center, are working on trying to improve
the effectiveness of the new vaccine introduced six years ago. "The
current vaccine has fewer side effects than its predecessor, but it
only provides immunity from whooping cough for a time," says Weiss.
"Genetics and new techniques in molecular biology and immunology have
enhanced research by allowing scientists to see things that they
couldn't see five or ten years ago, but there is still no known way to
test for pertussis immunity. Some people have a stronger immunity to
the disease than others, and we are trying to find out why."
and Weiss are also recruiting children between the ages of six months
and five years for a study in the effectiveness of the current vaccine.
The new DTP (diphtheria, tetanus, and pertussis) vaccine is given to
children at two, four, and six months and given as a booster at 12 to
18 months and at five years of age. Instead of containing the entire
killed bacterium, it contains only isolated parts.
believes the new vaccine is good, it does have problems. "One of the
problems with the new vaccine is that researchers are still dissecting
out what parts of the Bordetella pertussis
are infectious," says Weiss. However, the new vaccine has less side
effects than the whole bacteria, which caused high fevers and swelling
at the injection site.
Pertussis is not just a disease of
infants; older children and adults can become infected also. Treatment
with erythromycin helps prevent the spread of pertussis, which can be a
life-threatening illness for infants. Left untreated, an older brother,
sister, or parent may serve as a reservoir of bacteria that can give a
young child or infant whooping cough. Small babies cannot clear the
bacteria out of their bodies very well and the toxin-induced secretions
can suffocate them.
So when should parents worry? Pertussis
patients rarely have high fevers. "A persistent cough without fever is
what I worry about," says Connelly. Whooping cough begins like a cold.
But if the coughing lasts more than two weeks or is so strong that it
causes the patient to choke or even lose his dinner, there is a chance
that it is pertussis.
Connelly's advice to parents who want to
protect young children from whooping cough: "Make sure that the
children receive their vaccinations on schedule, and keep them at least
three feet or an arms length away from anyone with a coughing illness."
The pertussis bacteria is transmitted in droplets and can be spread
through direct contact or through the air.