Pertussis, Chain of Infection, and Immunization Principles

Practice vocabulary flashcards covering the pathogenesis, toxins, clinical stages, prevention, and immunology concepts associated with Bordetella pertussis and vaccines.

Zoonosis

A disease primarily found in animals, named using the prefix 'zo' which means animal.

Tus

The Latin word meaning 'cough', from which product names like Robitussin and the condition pertussis are derived.

Bordetella pertussis

The gram-negative bacterium that acts as the pathogen responsible for whooping cough, having humans as its only reservoir.

Subclinical

A condition in which an individual exhibits no signs or symptoms of disease but can still harbor and shed the pathogen as a carrier.

Filamentous hemagglutin

A bacterial surface protein on Bordetella pertussis that acts as the first virulence factor by attaching the pathogen to specific host cell receptors.

Catarrhal stage

The initial phase of a pertussis infection where the bacteria gradually increase in number, causing subtle damage and general feelings of illness primarily due to endotoxin release.

Paroxysmal stage

The severe, convulsive phase of pertussis characterized by violent, spasmodic, and uncontrollable coughing fits that can lead to gasping and a distinctive whooping sound.

Lipid A

The endotoxin found in the outer cell wall membrane of gram-negative bacteria like Bordetella pertussis that can trigger systemic reactions and potentially shock when released.

Cilia

Microscopic, finger-like cellular projections lining the respiratory tract that beat in a coordinated manner to transport mucus out of the airways.

Tracheal cytotoxin

An exotoxin secreted by Bordetella pertussis that specifically targets and destroys ciliated cells within the trachea.

Pertussis toxin

An exotoxin produced by Bordetella pertussis that transforms respiratory mucus into a thick, ropey substance that cannot be easily moved or coughed out.

Antitoxin

A drug treatment categorized as secondary prevention that neutralizes and clears circulating exotoxins to halt ongoing cellular damage.

DTaP

A childhood combination vaccine featuring a large pertussis component, administered at two, four, and six months, followed by booster doses around 15 months and age five.

Tdap

A booster vaccine formulated with a reduced quantity of pertussis antigen, given around age 11 or 12 and recommended every ten years thereafter.

Active immunity

Immunity produced by the body's own immune system following exposure to an antigen—either naturally through infection or artificially through vaccination—resulting in the formation of memory cells.

Herd immunity

A public health phenomenon (also called community immunity) wherein vaccinating a critical threshold of a population ($80\%$ to $95\%$) prevents a pathogen from circulating, protecting unvaccinated or immunocompromised individuals.

Attenuated vaccine

A vaccine containing a live but weakened whole pathogen that replicates within the host to stimulate robust, often lifelong immunity without causing disease-induced damage.