The first identification and retrospective study of Severe Fever with Thrombocytopenia Syndrome in Japan.
BACKGROUND
Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a novel bunyavirus reported to be endemic in central and northeastern China. This article describes the first identified patient with SFTS and a retrospective study on SFTS in Japan.


METHODS
Virologic and pathologic examinations were performed on the patient's samples. Laboratory diagnosis of SFTS was made by isolation/genome amplification and/or the detection of anti-SFTSV immunoglobulin G antibody in sera. Physicians were alerted to the initial diagnosis and asked whether they had previously treated patients with symptoms similar to those of SFTS.


RESULTS
A female patient who died in 2012 received a diagnosis of SFTS. Ten additional patients with SFTS were then retrospectively identified. All patients were aged ≥50 years and lived in western Japan. Six cases were fatal. The ratio of males to females was 8:3. SFTSV was isolated from 8 patients. Phylogenetic analyses indicated that all of the Japanese SFTSV isolates formed a genotype independent to those from China. Most patients showed symptoms due to hemorrhage, possibly because of disseminated intravascular coagulation and/or hemophagocytosis.


CONCLUSIONS
SFTS has been endemic to Japan, and SFTSV has been circulating naturally within the country.
Department of Hematology.
Toru
T
Takahashi
Ken
K
Maeda
Tadaki
T
Suzuki
Aki
A
Ishido
Toru
T
Shigeoka
Takayuki
T
Tominaga
Toshiaki
T
Kamei
Masahiro
M
Honda
Daisuke
D
Ninomiya
Takenori
T
Sakai
Takanori
T
Senba
Shozo
S
Kaneyuki
Shota
S
Sakaguchi
Akira
A
Satoh
Takanori
T
Hosokawa
Yojiro
Y
Kawabe
Shintaro
S
Kurihara
Koichi
K
Izumikawa
Shigeru
S
Kohno
Taichi
T
Azuma
Koichiro
K
Suemori
Masaki
M
Yasukawa
Tetsuya
T
Mizutani
Tsutomu
T
Omatsu
Yukie
Y
Katayama
Masaharu
M
Miyahara
Masahito
M
Ijuin
Kazuko
K
Doi
Masaru
M
Okuda
Kazunori
K
Umeki
Tomoya
T
Saito
Kazuko
K
Fukushima
Kensuke
K
Nakajima
Tomoki
T
Yoshikawa
Hideki
H
Tani
Shuetsu
S
Fukushi
Aiko
A
Fukuma
Momoko
M
Ogata
Masayuki
M
Shimojima
Noriko
N
Nakajima
Noriyo
N
Nagata
Harutaka
H
Katano
Hitomi
H
Fukumoto
Yuko
Y
Sato
Hideki
H
Hasegawa
Takuya
T
Yamagishi
Kazunori
K
Oishi
Ichiro
I
Kurane
Shigeru
S
Morikawa
Masayuki
M
Saijo
D000818:Animals; D002044:Bunyaviridae Infections / Q000175:diagnosis* / Q000821:virology; D002522:Chlorocebus aethiops; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D016856:Phlebovirus / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D012189:Retrospective Studies; D014709:Vero Cells
Hemophagocytosis; SFTS; SFTS virus: Japan; Severe fever with thrombocytopenia syndrome; bunyavirus; tick borne virus infection