Brain abscess due to Haemophilus aphrophilus.

H aphrophilus (H. aphrophilus) is a member of normal oral cavity flora. The organism can be isolated from gingival scrapings, interdental material, and dental plaque.1 Although rare, brain abscesses are one of the most serious infections of the CNS. Dental pathologies and therapeutic interventions may have a role in the pathogenesis of brain abscesses. The rationale for this paper is to report a rare case of brain abscess caused by H. aphrophilus with a possible odontogenic origin. A 28-year-old male patient with an unremarkable previous medical history was admitted to the emergency service of our hospital. He had been well until 10 days before, when headache and vomiting developed consecutively. He noticed weakness on the right side 3 days ago. On admission the patient was conscious, had no fever and neck stiffness. Neurological examination revealed right hemiparesis. Cardiovascular, respiratory, and abdominal examinations were found to be normal. White blood cell count was 9800/mm3 with 80% neutrophils. The erythrocyte sedimentation rate was 10 mm/h, and C-reactive protein level was 3.02 mg/l. Biochemical parameters were within normal limits. A CT of the brain showed a hypodense lesion in the left temporoparietal area. An MRI of the head revealed a left sided lesion with contrast ring enhancement, peripheral edema, and mass effect to the left ventricle (Figure 1). Intracranial mass or abscess was suspected as the likely diagnosis. Craniotomy was performed and the lesion was identified as an abscess with aspiration and was totally removed with its capsule. Abscess material was cultured, and empirical antibiotic therapy was started with ceftriaxone (2 gr every 12 hours IV) and metronidazole (500 mg every 6 hours IV). Culture of the abscess material grew gram negative, catalase negative, and oxidase positive coccobacillus. The organism fermented glucose, fructose, and sucrose. It did not require X and V factors and was identified as Haemophilus aphrophilus by the API NH System (bioMerieux, Marcy l’Etoile, France). The isolate was susceptible to penicillin, ampicillin, amoxicillin-clavulanic acid, ceftazidime, ceftriaxone, and trimethoprim-sulfamethoxazole by the disk diffusion method. To find out the source of this infection transesophageal echocardiography was performed, and infective endocarditis or any valvular heart disease were excluded. Otorhinolaryngologic examination did not reveal any pathology. Dental examination showed multiple missing teeth, caries, chronic periodontitis, and root rest infection of bilateral maxillary first molar teeth. Following the surgery the patient’s headache resolved rapidly. Neurologic symptoms improved within a week, and the patient recovered promptly. Dental treatment was initiated in the hospital. After 3 weeks of antibiotic therapy, he was discharged without any neurologic deficit. Haemophilus aphrophilus is a small, pleomorphic, nonmotile, facultatively anaerobic, slow growing gram negative coccobacillus. It is oxidase positive; catalase, urease, and indole negative and can ferment glucose, sucrose, lactose, and maltose. Unlike the other members of the genus Haemophilus, it does not have a strict requirement for X factor (hemin) or V factor (nicotinamide-adenine dinucleotide).1 Haemophilus aphrophilus has been reported to be the causative agent of different clinical manifestations. It is a wellknown cause of infective endocarditis, and it has also been identified as the etiological agent in a number of cases with brain abscess, meningitis, spondylodiscitis, paravertebral abscess, osteomyelitis, arthritis, bacteremia, endophthalmitis, lymphadenitis, and soft tissue infections. Brain abscess due to H. aphrophilus is infrequent. Huang et al2 reported that osteoarticular infection was the major clinical entity in their series. Only one out of 28 patients had brain abscess in the mentioned study. Certain predisposing and associated conditions for H. aphrophilus infections are described in the literature such as dental procedures or diseases, poor oral hygiene, underlying heart diseases, immune compromise, local trauma, and cirrhosis.1-3 Although it is difficult to define the primary infectious site, brain abscesses frequently result from a contiguous focus of infection, mostly in the middle ear or sinuses. It has been reported that dental procedures and diseases may have Clinical Notes