Case Presentation:
Our patient is a 35 years old Mexican male with a history of HIV infection. He is compliant with anti-retroviral therapy and also has a history of alcohol abuse. He presented to the ED with acute onset of headache and confusion associated with vomiting for 6 hours. On admission, he was unable to provide history, but his partner reported recent binge drinking without sick contacts or recent travel. In the ED, he was found to be febrile, tachycardic, and agitated, requiring admission to the MICU for acute encephalopathy. Initial CT Head, Abdomen and Pelvis as well as urine toxicology were negative. His mental status deteriorated, requiring intubation. His lumbar puncture was consistent with bacterial meningitis and he was placed on appropriate antibiotics. His blood cultures ultimately revealed Streptococcus Gallalyticus. Transthoracic echocardiography and then transesophogeal echocardiography were both negative and ruled out endocarditis. Cerebral spinal fluid cultures remained negative and his CD4 count was 83. A repeat CT Abdomen was performed which showed evidence of colitis. His stool cultures were positive for many Strongyloides Larve and Ivermectin was initiated. Given culture speciation antibiotics were deescalated to Ceftriaxone and he had a rapid resolution of symptoms. He was extubated, transferred to a medicine floor and was eventually discharged with plans for outpatient colonoscopy and Infectious Disease follow up.
Discussion:
Streptococcus Gallalyticus, formerly known as Streptococcus Bovis, is a Gram positive bacteria known to be linked to colorectal disease and endocarditis. First identified in cattle, it was later detected in gut flora in up to 15% of humans. There is also an association with Strongyloides which, in theory, may increase bowel wall permeability and thus facilitating translocation of gut flora. S.Bovis is identified as a rare cause of bacterial meningitis. In one study, only five of 1561 patients with bacterial meningitis were infected with S.Bovis. In their literature review, Samkar and colleagues found risk factors (including immunosuppressive therapy, cancer, alcoholism, etc.) for 50% of patients with S.Bovis meningitis. Of those patients, 15 out of 24 patients had colonic disease and 5 of 27 had endocarditis. Surprisingly, 41% of patients were founding to have co-infection with Strongyloides stercolaris, several of which also had HIV or HTLV.
Conclusions:
As this organism is not well known to cause meningitis, suspicion must remain high. Especially in patients that are immunosuppressed, such as our patient with HIV and low CD4 count, a broader differential diagnosis is required. Input from both cardiology and gastroenterology is advised as there is a likelihood of colon disease or endocarditis. Concomitant infection with Strongyloides should also be evaluated especially in patients who originate from or traveled to endemic areas.