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Whooping Cough (cont.)

Whooping cough is caused by the bacteria Bordetella pertussis. Humans are the only known reservoir of these bacteria.

Whooping cough is spread by contact with droplets coughed out by someone with the disease or by contact with recently contaminated hard surfaces upon which the droplets landed. The bacteria thrive in the respiratory passages where they produce toxins that damage the tiny hairs (cilia) that are needed to remove particulate matter and cellular debris that are normally introduced into the airways with each breath. This results in an increased inflammation of the respiratory passages, and the typical cough which is the hallmark of the infection. Whooping cough is contagious from seven days after exposure to the bacteria and up to three weeks after the onset of coughing spasms. The most contagious time is during the first stage of the illness.

Initially thought to be a disease of childhood, recent studies have shown that adults are susceptible to whooping cough and account for up to 25% of cases. The disease, however, tends to be milder in adults and adolescents—a persistent cough much like an upper respiratory infection or cold. Because of this fine distinction, the diagnosis of whooping cough is frequently missed in that population and thus allows the bacteria to spread to more susceptible infants and children.

Whooping cough is highly contagious. Between 75%-100% of unimmunized household contacts of a person with pertussis will develop the disease. Even among fully immunized and naturally immunized people living in the same household, there have been reports of undetectable infection following extreme exposure.