Published Date: 2013-02-20 18:13:24
Subject: PRO/AH/EDR> Severe fever w/ thrombocytopenia synd. - Japan (02): (HA)
Archive Number: 20130220.1551946

SEVERE FEVER WITH THROMBOCYTOPENIA SYNDROME - JAPAN (02): (HIROSHIMA)
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[1]
Date: Wed 20 Feb 2013
Source: The Asahi Shimbun [edited]
http://ajw.asahi.com/article/behind_news/social_affairs/AJ201302200053


A newly identified deadly virus probably transmitted by blood-sucking ticks is causing concern after experts confirmed it in Japan only a few years after it 1st surfaced in China. To date, there have been 4 deaths in Japan. The latest is that of a man who died last summer in Hiroshima Prefecture after contracting "severe fever with thrombocytopenia syndrome" (SFTS), the Hiroshima prefectural government stated on Tue 19 Feb 2013. SFTS was 1st reported in China in 2009. Scientists identified the virus behind it in 2011. Figures put the mortality rate at 12 percent in China.

The disease was 1st detected in Japan in late January this year [2013]. A physician researching the unexplained death of a woman last autumn in Yamaguchi Prefecture asked the National Institute of Infectious Diseases to test blood samples. Following a positive identification, the Health Ministry called for information on other suspected cases nationwide and gathered blood and other samples. Pathologists identified further cases on 13 Feb 2013 and attributed the deaths last autumn of 2 men from Ehime and Miyazaki prefectures to SFTS. All 4 cases occurred in western Japan.

There is now concern nationwide. Medical institutions and public health centers have made about 30 inquiries with the Health Ministry. Ministry officials said samples from 9 suspected cases await testing. The disease has an incubation period of between 6 days and 2 weeks. Symptoms then emerge, which may include fever, diarrhea and stomachache. There may also be a reduction in the concentration of blood platelets and white blood corpuscles. In all 4 confirmed deaths, the patients died one to 2 weeks after developing symptoms. At the time, doctors were unable to establish the cause of death, and none of the victims had traveled overseas immediately prior to infection, the ministry officials said.

How the 4 patients in Japan contracted SFTS remains unclear. No traces of tick bites were found on their bodies. Moreover, the SFTS virus has not been found in ticks in Japan. In China, the virus was found in 5.4 percent of ticks sampled in endemic areas, which suggests ticks are the vectors. Ticks typically live in grassland, and 97 percent of SFTS infections identified in China involved farmers in mountainous areas. Rat mites and house dust mites do not carry the SFTS virus.

The viruses found in the 4 Japanese who died had an almost identical genetic profile, but it differed slightly from the genome of the Chinese strain. Masayuki Saijo, director of the Department of Virology at the National Institute of Infectious Diseases, said the virus had likely been in Japan for some time. "I don't believe that these deadly viruses emerged out of the blue," Saijo said. "A sharp increase in infections is improbable."

More than 200 people in China are thought to have contracted the disease so far, according to Chinese figures. No vaccines or palliative drugs exist, so treatment is centered on symptomatic therapy, such as alleviating fever and stanching bleeding.

Ticks are widespread across Asia and Oceania. Usually measuring only a few millimeters in size, an adult tick bloats to resemble a blueberry nearly one centimeter wide after gorging on the blood of its host.

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[2]
Date: Wed 20 Feb 2013
Source: The Japan Daily Press [edited]
http://japandailypress.com/health-ministry-identifies-4th-death-attributed-to-tick-related-virus-2023678


The Japanese Health Ministry stated on Tuesday [19 Feb 2013] that a 4th victim has been identified as dying from a tick-borne virus infection. The victim, a man from Hiroshima Prefecture, died in the summer, making him the 1st among 3 others who died in the fall. These 4 instances are said to be the country's 1st occurrences of the virus, for which, as of now, there is no vaccine.

Just last week, the 2nd and 3rd deaths were revealed, one man from Ehime Prefecture and another other from Miyazaki Prefecture, followed by a January 2013 statement that said a woman from Yamaguchi Prefecture was believed to be the 1st. The infection has been identified as thrombocytopenia syndrome, which causes a severe fever that usually develops within 2 weeks. Other symptoms can include nausea, depletion of blood platelets, a decrease in appetite, and headaches. The virus was 1st discovered in China in 2009 and, until now, has been understood as being transmitted by mite or tick bites.

What makes this situation more peculiar is that no bite marks have been found on any of the victims' bodies, and they have no records of recent overseas travel. In addition, genetic tests have shown that this strain of the virus has originated in Japan, not China. While last week, the Health Ministry said it was not necessary to be concerned about the infection's spread across the country, as the deaths were only identified in re-examined overlooked cases, the National Institute of Infectious Diseases will now look into 9 other suspected cases that have been reported throughout Japan.

[Byline: Adam Westlake]

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Communicated by:
ProMED-mail <promed@promedmail.org>

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[3]
Date: Tue 19 Feb 2013
Source: Yomiuri Shimbun, evening edition [in Japanese, trans. Corr.KI, edited)


[Extracted from text]:

"4th tick bite death confirmed, 4 confirmed cases, 9 suspected cases..."

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Communicated by:
ProMED-mail Correspondent Kunihiko Iizuka

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[4]
Date: Thu 31 Jan 2013
Source: The National Institute of Infectious Diseases, Infectious Agents Surveillance Report [in Japanese, trans. Corr.KI, edited]
http://www.nih.go.jp/niid/ja/sfts/sfts-iasrs/3216-pr3963.html


[Extracted from text]:

- We found an adult with no foreign travel history exhibiting fever, vomiting, diarrhea (black), and no signs of tick-bites.
- White blood corpuscle 400/mm3, Blood platelet 8.9-104/mm3, high AST, ALT, LDH, CK.
- Very high rate of ferritin.
- Haematuria and proteinuria in urine.
- Separated SFTS virus in blood.
- Negative for ELISA, IF antibody in blood serum.
- Confirmed antigen and nucleic acid of SFTSV from biopsy.

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Communicated by:
ProMED-mail Rapporteur Kunihiko Iizuka

[ProMED-mail thanks Kunihiko Iizuka for these reports from Japanese sources.

Severe fever with thrombocytopenia syndrome (SFTS) is a serious infectious disease with a 12 percent case-fatality rate that has been documented in 6 rural provinces in northeast and central China. SFTS is caused by a novel bunyavirus, severe fever with thromobocytopenia syndrome virus (SFTSV) (1). The major clinical signs and symptoms of SFTS are fever, thrombocytopenia, leukopenia, and elevated serum hepatic enzyme levels.

The background to the identification and characterisation of the virus responsible for SFTS in China (and now in Japan) is described in Science, Vol. 330. no. 6000, pp. 20-21 (http://www.sciencemag.org/cgi/content/full/330/6000/20), Li Zhao et al in Emerging Infectious Disease, Volume 18, Number 6, June 2012 (http://wwwnc.cdc.gov/eid/article/18/6/11-1345_article.htm), and ProMED-mail posts: Fatal illness, novel phlebovirus-associated - China 20101005.3613 and Severe fever w/ thrombocytopenia synd. - Japan: (EE) fatalities 20130214.1542725.

It seems well-established now that the virus responsible for this syndrome is an arbovirus classified in the genus _Phlebovirus_ of the family _Bunyaviridae_. This SFTS virus, or a closely related phlebovirus, has now been recorded in 3 prefectures of Western Japan and has been responsible for 4 cases of SFTS, all fatal, in rural Japan, and perhaps a further 9 suspected cases. The information released so far indicates that the phleboviruses isolated from patients with SFTS in China and Japan are similar but not identical. The presence of these viruses in ticks in Japan has not yet been confirmed, and other routes of transmission may have to be considered. Further information is awaited concerning the characterisation of these SFST-associated viruses isolated in China an Japan.

A map of the prefectures of Japan can be accessed at http://www.japan-guide.com/list/e1002.html. - Mod.CP

A HealthMap/ProMED-mail map can be accessed at: http://healthmap.org/r/1rMj.]

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