Taxonomy
Family: Alcaligenaceae

Natural habitats
B. pertussis is thought to be a strictly human pathogen
The bacterium is spread by airborne droplets, its incubation period is 7-14 days.

Clinical significance
B. pertussis cause pertussis, or whooping cough.

Pertussis (or whooping cough)
is an infection of the respiratory system characterized by a “whooping” sound when the person breathes in.

B. pertussis continues to circulate in population where high vaccination coverage of infants and children is achieved, because the protection induced after natural infection and vaccination decreases after several years.

Pertussis is most dangerous in infants, and most hospitalizations and death occur in this age group.
The signs and symptoms are similar to a common cold; running nose, sneezing, mild cough, and low-grade fever.
The patient becomes more contagious during the catarral stage of infection, normally two weeks after the coughing begins.

It may become airborne when the persons cough, sneezes, or laughs.

The cough is a crowing inspiratory sound characteristic of pertussis. After a spell, the patient might make a “whooping” sound when breathing in, or may vomit.

Adults have milder symptoms, such as prolonged coughing without the “whoop”.
Infants less than six month also may not have the typical whoop.

A coughing spell may last a minute or more, producing cyanosis, apnoea, and seizures.

When not in a coughing fit, the patient does not experience trouble breathing.