Unusual presentation of a severely ill patient having severe fever with thrombocytopenia syndrome: a case report.
BACKGROUND
Severe fever with thrombocytopenia syndrome is an emerging infectious disease caused by a novel phlebovirus belonging to the family Bunyaviridate. Emergence of encephalitis/encephalopathy during severe fever with thrombocytopenia syndrome progression has been identified as a major risk factor associated with a poor prognosis. Here we report the case of a severely ill patient with severe fever with thrombocytopenia syndrome virus-associated encephalitis/encephalopathy characterized by a lesion of the splenium, which resolved later.


METHODS
A 56-year-old Japanese man presented with fever and diarrhea, followed by dysarthria. Diffusion-weighted magnetic resonance imaging demonstrated high signal intensity in the splenium of the corpus callosum. The severe fever with thrombocytopenia syndrome virus genome was detected in our patient's serum, and the clinical course was characterized by convulsion, stupor, and hemorrhagic manifestations, with disseminated intravascular coagulation and hemophagocytic lymphohistiocytosis. Supportive therapy not including administration of corticosteroids led to gradual improvement of the clinical and laboratory findings, and magnetic resonance imaging demonstrated resolution of the splenial lesion. The serum severe fever with thrombocytopenia syndrome viral copy number, which was determined with the quantitative reverse-transcription polymerase chain reaction, rapidly decreased despite the severe clinical course. Our patient's overall condition improved, allowing him to be eventually discharged.


CONCLUSIONS
Patients with encephalitis/encephalopathy due to severe fever with thrombocytopenia syndrome virus infection may have a favorable outcome, even if they exhibit splenial lesions and a severe clinical course; monitoring the serum viral load may be of value for prediction of outcome and potentially enables the avoidance of corticosteroids to intentionally cause opportunistic infection.
Department of Internal Medicine, Uwajima City Hospital, 1-1 Goten-machi, Uwajima City, Ehime, 798-8510, Japan. kaneko@uwajima-mh.jp.
Masahiko
M
Kaneko
Department of Internal Medicine, Uwajima City Hospital, 1-1 Goten-machi, Uwajima City, Ehime, 798-8510, Japan.
Masaki
M
Maruta
Department of Internal Medicine, Uwajima City Hospital, 1-1 Goten-machi, Uwajima City, Ehime, 798-8510, Japan.
Hisaharu
H
Shikata
Department of Neurosurgery, Ehime University Graduate School of Medicine, Shitsukawa, Toon City, Ehime, 791-0295, Japan.
Kengo
K
Asou
Ehime Prefectural Institute of Public Health and Environmental Science, 8-234 Sanbancho, Matsuyama, Ehime, 790-0003, Japan.
Hiroto
H
Shinomiya
Department of Pathology, National Institute of Infection Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.
Tadaki
T
Suzuki
Department of Pathology, National Institute of Infection Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, 162-8640, Japan.
Hideki
H
Hasegawa
Department of Virology 1, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo, 208-0011, Japan.
Masayuki
M
Shimojima
Department of Virology 1, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo, 208-0011, Japan.
Masayuki
M
Saijo
D001853:Bone Marrow / Q000473:pathology / Q000821:virology; D001927:Brain Diseases / Q000473:pathology / Q000821:virology*; D003337:Corpus Callosum / Q000473:pathology / Q000821:virology*; D003967:Diarrhea / Q000209:etiology / Q000821:virology; D038524:Diffusion Magnetic Resonance Imaging; D005334:Fever / Q000209:etiology / Q000821:virology*; D005440:Fluid Therapy; D006801:Humans; D051359:Lymphohistiocytosis, Hemophagocytic / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010217:Phlebotomus Fever / Q000175:diagnosis*; D017713:Platelet Transfusion; D012640:Seizures / Q000821:virology; D013921:Thrombocytopenia / Q000821:virology*; D016896:Treatment Outcome
Case report; Encephalitis/encephalopathy; Reversible splenial lesion syndrome; Serum viral load; Severe fever with thrombocytopenia syndrome