Which statement is true regarding Bordetella pertussis infection?

The statement regarding Bordetella pertussis infection that is true is that isolation of the organism from clinical specimens is greatest during the early stages of illness. During the initial phase of Bordetella pertussis infection, which is characterized by mild respiratory symptoms, the bacteria are actively replicating in the nasopharynx. During this early phase, the likelihood of isolating the organism from a nasopharyngeal swab or aspirate is significantly higher. This is an important point for clinicians as early diagnosis often hinges on laboratory confirmation through culture or PCR testing, both of which are most effective when performed soon after symptom onset.

Clinical diagnosis may be more challenging early on due to nonspecific early symptoms. The documentation of leukocytosis in whooping cough typically shows an increase in lymphocytes rather than polymorphonuclear leukocytes, which mischaracterizes the typical leukocyte response to the infection. Additionally, while vaccination helps reduce the severity of illness, it does not provide lifelong immunity to pertussis. There can be waning immunity over time, which is why booster shots are recommended. Understanding these aspects of Bordetella pertussis infection can significantly aid in proper diagnosis and management of the disease.