Public
Health England has updated its information for public health professionals
relating to pertussis (whooping cough).
Whooping
cough is a highly infectious disease
that is usually caused by Bordetella
pertussis. A similar illness is caused by B. parapertussis, but this is not preventable with presently
available vaccines.
There
is an initial catarrhal stage, followed by an irritating cough that gradually becomes
paroxysmal, usually within one to two weeks. The paroxysms are often followed
by a characteristic ‘whoop’ or by vomiting. In young infants, the typical
‘whoop’ may never develop and coughing spasms may be followed by periods of
apnoea. The illness often lasts for two to three months. In older children and
adults, the disease may present as persistent cough without these classic
symptoms and therefore not be recognised as whooping cough.
Pertussis
may be complicated by bronchopneumonia, repeated vomiting leading to weight
loss, and cerebral hypoxia with a resulting risk of brain damage. Severe
complications and deaths occur most commonly in infants under six months of
age. Minor complications include subconjunctival haemorrhages, epistaxis
(nosebleeds), facial oedema, ulceration of the tongue or surrounding area, and
suppurative otitis media.
Transmission
of the infection is by respiratory droplet, and cases are most infectious
during the early catarrhal phase. The incubation period is between six and 20
days and cases are infectious from six days after exposure to three weeks after
the onset of typical paroxysms.
Posted by Dr. Tim Sandle
