An
infection of the nose and throat caused by the bacterium Corynebacterium
diphtheriae. Symptoms include sore throat, swollen neck glands and a discharge
from the nose. The bacteria can also produce a toxic substance capable of
damaging nerves or the heart.
Diphtheria
is suspected when a white or grey membrane is seen on the back of the throat and
is confirmed when the bacteria are seen under the microscope and grown in the
laboratory.
The
disease is spread directly from person-to-person, by contact with airborne
droplets from the nose or throat, or indirectly by contact with articles soiled
with discharges from the nose or throat. Diphtheria has been rare in Australia since the use of an
effective vaccine.
Incubation
period
Usually
2-5 days.
Infectious
period
Without
antibiotic therapy, usually less than 2 weeks, occasionally as long as 6 months.
No longer infectious after completing 14 days of appropriate antibiotic
therapy.
Control
of spread
Widespread
immunisation against diphtheria is the only effective control. Immunisation
against diphtheria commences in infancy. Booster doses of diphtheria vaccine are
given in conjunction with tetanus vaccine every 10 years in adult
life.
- People
with diphtheria need to be kept in isolation until they are proven to be free of
the disease.
- Contacts
(those having close physical association) of people with diphtheria need to be
investigated for the disease, receive antibiotics and receive vaccination.
- Family
or household contacts should be excluded from school, preschool or child care
until cleared to return by an appropriate health authority.
- Contacts
whose work involves food handling or caring for unimmunised children are
excluded from work until they are proven to be free of infection.
- People
travelling to countries where diphtheria is common should receive a full
immunisation course or a booster dose of vaccine (if a full course has already
been completed).
Treatment
Specific
treatment with antibiotics and an antidote to the toxin is available.
Diphtheria
is a notifiable disease.
Adapted
from "You’ve got What?", with the permission of the Department of Human
Services, South
Australia.