Invasive Pasteurellosis of the Central Nervous System - How much can we see on a CT?

A 59-year-old asthmatic man was admitted to our Emergency Department after a 48-hour history of headache, vomiting, and acute altered mental status. At admission, he had a Glasgow Coma Scale score of 6, fever, and generalized spasticity. Daily contact with dogs was reported. Laboratory test results were notable for high levels of C-reactive protein and procalcitonin. A cranial computed tomography (CT) scan revealed right occipital vasogenic edema. A lumbar puncture was performed, which showed purulent cerebrospinal fluid (CSF) with polymorphonuclear pleocytosis (more than 1000 cells/µL), glycopenia and increased protein levels. A diagnosis of bacterial meningitis was assumed, and he was transferred to the intensive care unit under sedation; invasive mechanical ventilation; and empirical therapy with ceftriaxone, ampicillin, and vancomycin. Pasteurella multocida was isolated from the patient’s blood, CSF, and tracheobronchial aspirate. Despite optimal antibiotherapy, his clinical condition worsened. A cranial CT-scan showed multiple abscesses, signs of ventriculitis, and cerebral infarction (Figure 1). The patient died 30 days after hospital admission.

FIGURE 1:

Contrast-enhanced CT scan: Intracerebral lesions involving the deep callus and white matter, especially on the right side. There is a diffuse sulcal leptomeningeal enhancement and on the ventricular contour and multiple lesions with temporo-occipital nodular enhancement. These aspects reflect the presence of brain abscesses and meningitis aggravated with ventriculitis and hydrocephalus.

This case describes an unusual form of Pasteurella multocida infection, an organism belonging to the normal oropharyngeal flora of domestic or wild animals - . Soft tissue infections after a bite or scratch are the most common forms of this condition. However, when other systems are affected, the result can be severe disease, such as meningitis or bacteremia . Early identification of this etiology through careful review of the patient’s clinical history is crucial for the establishment of recommended antibiotic therapy.