Ehrlichia Meningoencephalitis: A Case Series

Objective: We present the distinct clinical and laboratory findings in two cases of Ehrlichia meningoencephalitis, along with one suspected case. Background: The number of cases of Ehrlichia chaffeensis reported to the CDC has more than doubled from 2007-2017. A PubMed literature search using the words “Ehrlichiosis and meningoencephalitis” revealed five case reports with neurologic manifestations. Design/Methods: This is a retrospective observational study. Two elderly patients presented with encephalopathy, fever, transaminitis, thrombocytopenia, a positive E. chaffeensis Polymerase Chain Reaction (PCR) in Serum, and Cerebrospinal Fluid (CSF) with a lymphocytic or neutrophilic pleocytosis and elevated protein. One patient had similar symptoms and a positive E. chaffeensis PCR, but lumbar puncture was unable to be performed due to severe thrombocytopenia. They presented in May or June. Doxycycline was started within 2-3 days after presentation to the hospital. Follow up five months later revealed all patients were close, or back to baseline. Results and Conclusions: Suspicion of Ehrlichia meningoencephalitis should be raised in elderly patients presenting with fever and encephalopathy in the summer season with history of tick bite or residence in wooded areas. Thrombocytopenia and transaminitis should raise further suspicion. CSF studies typically show a lymphocytic pleocytosis and elevated protein. PCR technique allows for direct detection of pathogen-specific DNA and is the preferred method of detection during the acute phase of illness. Prompt treatment with doxycycline results in good outcomes. Doxycycline is not included in the typical meningitis regimen, therefore, this disease is important to quickly identify as delay in Doxycycline can result in worse outcomes.