Pertussis (also known as
whooping cough) bacteria get into a person's body through contact with an infected person's respiratory secretions. This commonly happens in one of two ways. Pertussis can be passed either through the air when an infected person coughs or sneezes, or when a healthy person touches a surface or object contaminated with the bacteria that cause the infection.
Through the Air
When an infected person coughs or sneezes, secretions filled with Bordetella pertussis (B. pertussis) bacteria are propelled a short distance (generally up to 3 feet) through the air and then deposited on the mucous membranes of the mouth, nose, or eyes of people who are nearby.
Contaminated Surfaces
Although it occurs less often, pertussis can also be spread when a person touches a surface or object contaminated with infectious droplets and then touches his or her own mouth, nose, or eyes.
Once inside the body, the
B. pertussis bacteria move into the lungs and begin to multiply. The period between when a person becomes infected with pertussis and the onset of
whooping cough symptoms is known as the incubation period. While the whooping cough incubation period is commonly 7 to 10 days, it can range from 4 to 21 days, and even may be as long as 42 days in rare cases.