Bordetella pertussis is a bacterium which is responsible for bordetella, also known as whooping cough. This infectious disease once killed thousands of people annually and caused substantial loss of work for patients who survived the infection. Today, it is relatively rare thanks to the fact that a vaccine has been developed. While Bordetella pertussis is still present in the human population, most people are able to resist colonization by the bacteria and thus remain healthy.
This bacterium is gram negative and aerobic, requiring air to survive. No hosts other than humans have been identified for the bacterium, and bordetella infections seem to run in cycles. Because of widespread vaccination practices, the people most at risk of infection are unvaccinated infants and older adults with immunity which has waned over time. Individuals who opt not to vaccinate are also at risk, and can serve as a reservoir for the bacteria, posing a risk to others because they carry the bacteria and can transmit it to people who are vulnerable.
When Bordetella pertussis enters the respiratory tract because someone has inhaled bacteria expelled by someone else, it immediately starts to colonize the airways. It secretes substances which help it stick to the tissue in the airway, and it also generates toxins which paralyze the cilia, making it difficult to clear the airways of mucus. People develop a distinctive whooping sound when they breathe as a result of inflammation triggered by the Bordetella pertussis bacteria, and they cough in an attempt to clear their airways. The immune system is also weakened by toxins secreted by the Bordetella pertussis bacteria.
Bordetella can cause extremely severe coughing. People have been known to break ribs as a result of the infection. Treatment for people with an active Bordetella pertussis infection is primarily focused on giving antibiotics to decrease the intensity of the infection, and on providing support to help the patient breathe more comfortably. Even with treatment, whooping cough can be very debilitating, and the patient is highly contagious.
It is usually not necessary to take a culture to confirm Bordetella pertussis infection. The distinctive sound associated with the infection is enough for a doctor to determine that the patient has bordetella. People who have been diagnosed with this infection should follow the treatment protocol and avoid being around people who have not been vaccinated. In addition, they should avoid people with compromised immune systems, such as people with AIDS and cancer.