Medical researchers meeting in Toronto this
week called for a vaccination program to combat the increasing incidence of
pertussis (whooping cough) among adolescents and adults.
"Of the diseases for which immunization is routinely recommended,
pertussis is the most common", said Dr. Scott Halperin, a Professor of
Pediatrics and Associate Professor of Microbiology and Immunology at Dalhousie
University in Halifax. "While there is zero mortality from pertussis in
adolescents and adults, those who have or are in contact with young children
should be immunized in an attempt to protect infants, who suffer the highest
morbidity and mortality," he said at the American Society for Microbiology's
40th annual conference on antimicrobial agents and chemotherapy.
Pertussis, also known as whooping cough, is a highly contagious
respiratory infection that can be transferred from person to person through
airborne droplets from the nose or throat. The infection has an incubation
period of three to 12 days. The first symptoms are similar to those of the
common cold--runny nose, sneezing, low-grade fever and mild cough. But within
two weeks, the cough becomes more pronounced. Children may have episodes of
spasmodic coughing, forcing them to draw breath in quickly and sharply to make
the characteristic "whooping" noise. The illness can last as long as two
Dr. Halperin believes the recent pertussis outbreak in Victoria, B.C. is
one more reason why adolescents and adults should be immunized. "Vaccination
should be done to protect very young children and to reduce the disease burden
among adolescents and adults. When you look at the high degree of school
absenteeism, a cough that lasts for 40 days and staying awake for three to
four weeks, it's a disease well worth preventing."
Dr. Pierce Gardner of the Department of Medicine at the State University
of New York supports adolescent and adult pertussis immunization but
recommends selective, rather than universal vaccination in adults. "Pertussis
in adults has negligible mortality but is responsible for about one-quarter of
cases of chronic cough syndrome in young adults. Parents and other infant
caregivers are important transmitters of pertussis to infants, the group who
have the highest morbidity and mortality," he said at a conference lecture.
"Recommendations can be made for universal immunization of adolescents,
epidemic control, and targeted adults who give care to infants, such as health
care workers, day care staff and teachers," he said.
It is estimated that pertussis causes about 15 per cent of cough
illnesses in adolescents and adults, according to Health Canada. Adults and
adolescents whose last booster shot was more than ten years ago are no longer
protected by the vaccine and may therefore be susceptible to pertussis
infection. Largely unrecognized as having pertussis, they can unknowingly
transmit the disease to infants. Infants represent the group at greatest risk
for severe illness, disease complications and death.
According to the Laboratory Centre for Disease Control at Health Canada,
pertussis is among the top diseases preventable by routine vaccination, with
1,687 cases being reported in the first five months of this year. More than
4,500 cases were reported from January to October of 1999.