Chapter 131. Diphtheria and Other Infections Caused by Corynebacteria and Related Species (Part 5)

ManagementPatients in whom diphtheria is suspected should be hospitalized in respiratory isolation rooms, with close monitoring of cardiac and respiratory function. A cardiac workup is recommended to assess the possibility of myocarditis. In patients with extensive pseudomembranes, consultation with an anesthesiologist or an ear, nose, and throat specialist is recommended because of the possibility that tracheostomy or intubation will be required. In some settings, pseudomembranes can be removed surgically. Treatment with glucocorticoids has not been shown to reduce the risk of myocarditis or polyneuropathy.PrognosisFatal pseudomembranous diphtheria typically occurs in patients with nonprotective antibody titers and in unimmunized patients. ...
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Chapter 131. Diphtheria and Other Infections Caused by Corynebacteria and Related Species (Part 5) Chapter 131. Diphtheria and Other Infections Caused by Corynebacteria and Related Species (Part 5) Management Patients in whom diphtheria is suspected should be hospitalized inrespiratory isolation rooms, with close monitoring of cardiac and respiratoryfunction. A cardiac workup is recommended to assess the possibility ofmyocarditis. In patients with extensive pseudomembranes, consultation with ananesthesiologist or an ear, nose, and throat specialist is recommended because ofthe possibility that tracheostomy or intubation will be required. In some settings,pseudomembranes can be removed surgically. Treatment with glucocorticoids hasnot been shown to reduce the risk of myocarditis or polyneuropathy. Prognosis Fatal pseudomembranous diphtheria typically occurs in patients withnonprotective antibody titers and in unimmunized patients. The pseudomembranemay increase in size from the time it is first noted. Risk factors for death includebullneck diphtheria; myocarditis with ventricular tachycardia; atrial fibrillation;complete heart block; an age of >60 years or years old. As of 2006, it is recommended that (1) adults 19–64 years old receive asingle dose of Tdap if their last dose of Td (tetanus and reduced-dose diphtheriatoxoids, adsorbed) was >10 years earlier and (2) intervals of Nondiphtherial Corynebacteria and Related Species Nondiphtherial corynebacteria, which are also referred to as diphtheroids orcoryneforms, are a widely diverse collection of bacteria that are taxonomicallylumped together on the basis of their 16S rDNA signature nucleotides. Thediversity of this group is exemplified by the wide range in guanine-plus-cytosinecontent (45–70%). Although frequently considered colonizers or contaminants, thenondiphtherial corynebacteria have been associated with invasive disease,particularly in immunocompromised patients. Specifically, for example, theseorganisms have been implicated in bacteremia, particularly in association withcatheterization, endocarditis, prosthetic valve infection, meningitis, neurosurgicalshunt infection, brain abscess, peritonitis (often in the setting of chronicambulatory peritoneal dialysis), osteomyelitis, septic arthritis, urinary tractinfection, empyema, and pneumonia. Patients infected with nondiphtherialcorynebacteria usually have significant medical comorbidity orimmunosuppression. Several of these organisms, including C. jeikeium and C.urealyticum, are associated with resistance to multiple antibiotics. The relatedorganism Rhodococcus equi is associated with necrotizing pneumonia andgranulomatous infection, particularly in immunocompromised individuals. Otherrelated species that can cause infections in humans are Actinomyces (formerlyCorynebacterium) pyogenes and Arcanobacterium (formerly Corynebacterium)haemolyticum.