EID Journal: Two Dispatches On SFTS

Photo Credit Wikipedia

Tick Species Associated with SFTS in China

# 8804

 

 

SFTS or Severe Fever with Thrombocytopenia Syndrome - a tickborne Phlebovirus  - was first discovered in China in 2009, but has also been found in Japan and Korea. It is genetically similar to the recently discovered Heartland Virus (see MMWR: Heartland Virus Disease — United States, 2012–2013) that has been detected in roughly a dozen people here in the United States.

 

Phleboviruses are part of the very large family Bunyaviridae.

 

To date over three hundred Bunyaviruses have been identified around the world, with rodents often cited as carriers. While not all Bunyaviruses are dangerous to humans (some only infect plants), the Bunyavirus family include such nasties as Crimean-Congo hemorrhagic fever (CCHF), Hantaviruses, and Rift Valley Fever.

 

Most are spread via arthropod vectors (ticks, mosquitoes & sand flies), with the notable exception of Hantaviruses (see Hantaviruses Revisited), which are primarily spread via virus-laden feces and urine of rodents.

 

In 2011, we got our first good look at the disease when the NEJM published a study Fever with Thrombocytopenia Associated with a Novel Bunyavirus in China.  STFS has previously been associated with a 12% mortality rate in China. Since then we’ve seen reports both from Japan and South Korea (see Korean CDC On SFTS Cases) of fatal cases as well.

 

Like with CCHF, under the right conditions, human-to-human transmission of SFTS (via blood, mucus or other bodily fluids) has been documented. (see Person-to-person transmission of severe fever with thrombocytopenia Syndrome virus)

 

As a relatively newly discovered pathogen, we are just beginning to learn about its prevalence, both in ticks and in humans in SFTS endemic areas.  

 

Today, we’ve excerpts from two dispatches published in the CDC’s EID Journal that help in that regard.

 

The first, looks at the various species and the rate of SFTS infection among ticks collected South Korean. They found SFTSV in 5.7% of H. longicornis ticks tested, which represented 81.2% of the ticks sampled.  Other species tested were also found to carry the virus, but it isn’t yet known whether they can transmit it to humans. 

 

Severe Fever with Thrombocytopenia Syndrome Virus in Ticks Collected from Humans, South Korea, 2013

Seok-Min Yun¹, Wook-Gyo Lee¹, Jungsang Ryou, Sung-Chan Yang, Sun-Whan Park, Jong Yeol Roh, Ye-Ji Lee, Chan Park, and Myung Guk Han

Author affiliations: Korea Centers for Disease Control and Prevention, Cheongwon-gun, South Korea

Abstract

We investigated the infection rate for severe fever with thrombocytopenia syndrome virus (SFTSV) among ticks collected from humans during May–October 2013 in South Korea. Haemaphysalis longicornis ticks have been considered the SFTSV vector. However, we detected the virus in H. longicornis, Amblyomma testudinarium, and Ixodes nipponensis ticks, indicating additional potential SFTSV vectors.

 

The second study, this time out of China, is a seroprevalence study of healthy individuals, looking for evidence of prior infection with SFTS, without a history of severe illness. 

 

Antibodies against Severe Fever with Thrombocytopenia Syndrome Virus in Healthy Persons, China, 2013

Lei Zhang¹, Jimin Sun¹, Jie Yan, Huakun Lv, Chengliang Chai, Yi Sun, Bin Shao, Jianmin Jiang, Zhiping Chen, and Yanjun Zhang

Abstract

In June 2013, a subclinical infection with severe fever with thrombocytopenia syndrome virus (SFTSV) was detected in Zhejiang Province, China, prompting seroprevalence studies in 6 districts within the province. Of 986 healthy persons tested, 71 had IgG antibodies against SFTSV. This finding suggests that most natural infections with SFTSV are mild or subclinical.

Conclusions

SFTSV can cause severe disease and high rates of death among infected hospitalized patients. The virus also has the limited ability to be transmited from person to person through contact with contaminated blood, but secondary cases are generally less severe and have so far not resulted in fatalities (7–9). Nonetheless, there is great public health concern regarding SFTSV.

Our seroprevalence study was prompted by the identification of a subclinical, secondary infection that was most likely caused by person-to-person transmission of the virus from an infected family member with a fatal case of SFTS. We found an overall SFTSV seroprevalence of 7.2% among 986 healthy persons who reported no symptoms associated with SFTS. Because the seropositive participants in our study did not have contact with persons with diagnosed cases of SFTS, their infections most likely occurred through natural exposure. From this, we conclude that SFTSV infections are widespread in rural areas of Zhejiang Province, and only a small percentage of the infections result in clinical disease.

 

Like a lot of viruses, infection with SFTS appears to carry with it a wide range of illness – ranging from subclinical to mild to occasionally life-threatening.  Very few viruses are universally fatal (rabies comes close, though).

 

This is a pattern we see with everything from influenza to West Nile Virus to MERS. It is also a fact of life that surveillance is far more likely to pick up severe cases than mild ones, and that can sometimes skew our perception of just how deadly an emerging pathogen really is.

 

You don’t have to travel to Asia to be exposed to a potentially serious  tickborne disease.  The CDC maintains a long  (and growing) list of of tickborne pathogens available locally, including:

 

Babesiosis , Ehrlichiosis, Lyme disease, Rickettsia parkeri Rickettsiosis, Rocky Mountain Spotted Fever (RMSF), STARI (Southern Tick-Associated Rash Illness), Tickborne relapsing fever (TBRF), Tularemia, and 364D Rickettsiosis.

 

Whether a new and emerging threat, or simply our ability to finally recognize a long-time nemesis, it makes sense to take precautions against ticks and other vector-borne diseases.

 

For help in that regard, the following CDC website offers advice on:

 

Preventing Tick Bites

 

And for more on tickborne pathogens, you may wish to revisit:

 

EID Journal: Seroprevalence Of B. Miyamotoi In N.E. United States

The Tick Borne Identity

CDC: Estimate Of Yearly Lyme Disease Diagnoses In The United States

EID Journal: Novel Bunyavirus In Livestock - Minnesota

(Credit CDC)

 

 

# 7542

 

Bunyaviruses are an incredibly diverse family of negative stranded enveloped RNA viruses that are responsible for such dreaded diseases as Rift Valley Fever, Crimean - Congo Hemorrhagic Fever (CCHF), and Hantavirus.

 

While these viruses most commonly infect arthropods and rodents (and occasionally humans), curiously, one variety even infects plants - the (Tospovirsus) – and is responsible for tomato spotted wilt.

 

In the United States, probably the most common Bunyavirus infection reported is La Crosse (LAC) encephalitis, and less commonly Jamestown Canyon (JCV) and California encephalitis (CE). 

 

All three being mosquito vectored illnesses.

 

Over the past few years we’ve seen a new, often serious human infection emerge in Asia  - Severe Fever with Thrombocytopenia Syndrome (SFTS) - that produces a high fever, a low platelet count and and can lead to multiple organ failure.

 

SFTS first came to our attention in the spring and summer of 2009  after outbreaks were identified in China’s Hubei and Henan provinces.  While ticks were suspected as vectors, the pathogen behind this disease was not initially known.

 

In 2011, the NEJM published a study Fever with Thrombocytopenia Associated with a Novel Bunyavirus in China.  STFS has been associated with a 12% mortality rate in China.

 

Over the past year, we’ve seen reports of SFTS in Japan and Korea as well (see Japan Announces 4th SFTS Fatality,  Korean CDC On SFTS Cases).  Of note, we’ve also seen evidence of limited human-to-human transmission of this virus.

 

Person-to-person transmission of severe fever with thrombocytopenia syndrome virus.

Liu Y, Li Q, Hu W, Wu J, Wang Y, Mei L, Walker DH, Ren J, Wang Y, Yu XJ.

(Excerpt)

We concluded that SFTSV can be transmitted from person to person through contacting patient's blood.

 

Last year, in New Phlebovirus Discovered In Missouri we also learned of the discovery of another novel Bunyavirus – dubbed the Heartland Virus (HLV) - in two residents of Western Missouri. Last month CIDRAP NEWS reported that Researchers trace novel Heartland virus to Missouri ticks.

 

All of which serves as prelude to today’s report in the CDC’s EID Journal, where researchers in Minnesota conducted serological testing of domestic and captive farmed animals looking for evidence of SFTS and the Heartland virus.

 

What they found was an unexpectedly high prevalence (10%-18%) of antibodies (using an ELSIA reagent kit developed by China’s CDC) to SFTS in the cattle, goats, sheep, and elk they tested.   

 

Since the HLV and SFTF are antigenically cross reactive, the authors believe `the viruses detected in this region are most likely HLV or close relatives of HLV.’

 

The entire study is well worth reading, and is available at the link below.  I’ve excerpted the abstract and a small portion from the conclusion, as it speaks to the impact this discovery may have on public health.

 

Volume 19, Number 9—September 2013

Dispatch

Novel Bunyavirus in Domestic and Captive Farmed Animals, Minnesota, USA

Zheng Xing , Jeremy Schefers, Marc Schwabenlander, Yongjun Jiao, Mifang Liang, Xian Qi, Chuan Li, Sagar Goyal, Carol J. Cardona, Xiaodong Wu, Zerui Zhang, Dexin Li, James Collins, and Michael P. Murtaugh

Abstract

We tested blood samples from domestic and captive farmed animals in Minnesota, USA, to determine exposure to severe fever with thrombocytopenia syndrome virus and Heartland-like virus. We found antibodies against virus nucleoproteins in 10%–18% of samples from cattle, sheep, goats, deer, and elk in 24 Minnesota counties.

 

<SNIP>

Conclusion (EXCERPT)

Farmers, hunters, and persons with outdoor lifestyles may become infected when they are bitten by infected ticks. In addition, direct contact with secretions, body liquids, or feces from viremic animals would also put these persons and veterinarians at risk, if HLV- infected animals have substantial amounts of virus in blood and other tissues. The direct contact transmission of SFTSV has been reported in family clusters among persons with no history of tick bites, suggesting that person-to-person transmission may also occur (13–15).

 

Evidence that a novel phlebovirus infects domesticated and captive farmed animals as shown in this study validates the concern that an SFTSV- or HLV-like emerging pathogen could pose a serious public health threat in the United States. Epidemiologic studies with a broader scope need to be conducted to elucidate viral ecology, and effective measures must be adopted to control this virus before it spreads among humans.

 

 

 

Although most people think first of Lyme disease when they get a tick bite, The CDC lists a growing number of diseases carried by ticks in the United States, including: Anaplasmosis, Babesiosis , Ehrlichiosis, Lyme disease, Rickettsia parkeri Rickettsiosis, Rocky Mountain Spotted Fever (RMSF), STARI (Southern Tick-Associated Rash Illness), Tickborne relapsing fever (TBRF), Tularemia, and 364D Rickettsiosis.

We’ve discussed a number these in the past, including:

 

Referral: Maryn McKenna On Babesia And The Blood Supply

NEJM: Emergence Of A New Bacterial Cause Of Ehrlichiosis

tick . . . tick . . . tick . . .

Minnesota: Powassan Virus Fatality

 

Given the smorgasbord of  of diseases carried by ticks it makes sense to avoid their bites whenever possible.  This advice from the Minnesota Department of Health.

Korean CDC On SFTS Cases

Korean CDC  Alert For SFTS

 

# 7355

 

Catching up on an emerging disease we last looked at in February of this year  (see Japan Announces 4th SFTS Fatality) – Severe Fever With Thrombocytopenia Syndrome (SFTS) – caused by a tick borne Bunyavirus, has recently been confirmed in Korea.

 

To date over three hundred Bunyaviruses have been identified around the world, with rodents often cited as carriers. While not all Bunyaviruses are dangerous to humans (some only infect plants), the Bunyavirus family include such nasties as Crimean-Congo hemorrhagic fever, Hantaviruses, and Rift Valley Fever.

 

Most are spread via arthropod vectors (ticks, mosquitoes & sand flies), with the exception of Hantaviruses (see Hantaviruses Revisited), which are spread via the feces and urine of rodents.

 

SFTS first came to our attention in the spring and summer of 2009  after outbreaks were identified in China’s Hubei and Henan provinces.  While ticks were suspected as vectors, the pathogen behind this disease was not initially known.

 

In 2011, the NEJM published a study Fever with Thrombocytopenia Associated with a Novel Bunyavirus in China.  STFS has been associated with a 12% mortality rate in China.

 

Earlier this year (see SFTS Fatality Reported In Japan) we learned of the first known SFTS case in the country of Japan, and since then at least 15 cases have been identified in Japan (with 8 fatalities).

 

Last month, while our attentions were focused primarily on H7N9 and MERS-CoV, Korea’s CDC announced that retrospective testing of a patient who died in 2012 had confirmed Korea’s first known death from the SFTS causing virus (see Korea Times story First death by SFTS virus from tick bite confirmed).

The story goes on to say that another death was suspected, and that five others had been hospitalized with similar symptoms.

 

Fast forward to today, and the Yonhap News Agency is reporting on three additional deaths in Korea, now attributed to this virus.

 

Disease control agency says tick-borne virus kills four South Koreans

SEOUL, June 3 (Yonhap) -- A deadly tick-borne virus has killed four South Koreans and sickened two others, the state-run disease control agency said Monday.

 

The severe fever with thrombocytopenia syndrome virus killed a 63-year-old woman in the country's eastern region in August last year, though her infection of the virus was confirmed last month, according to the Korea Centers for Disease Control and Prevention (KCDC).

 

It was the country's first death caused by the virus, the KCDC said.

 

Last month, the virus also killed three other South Koreans -- a 73-year-old man and an 82-year-old woman, both in the country's southern resort island of Jeju, and a 74-year-old woman in the southeastern region, according to the KCDC.

(Continue . . . )

 

If you visit the Korean CDC’s homepage you’ll find an SFTS Q&A, a reporting  Hotline 043-719-7086, and a a brief press release on the identified cases.

 

As with many emerging and re-emerging pathogens, the Bunyavirus behind these infections has almost certainly in the environment, and causing human illness, for many, many years. 

 

We are only now starting to recognize SFTS as a specific illness, and with modern diagnostic tests, can now identify the causative virus. Whether this virus’s geographic range is expanding, or its incidence in humans is increasing, is something we simply don’t know yet.

 

But tickborne diseases certainly appear to be on the rise in the United States and around the world, with Lyme disease alone blamed for 20,000+ infections each year (MMWR Lyme Disease --- United States, 2003—2005).

The CDC lists a number of diseases carried by ticks in the United States. Included are:

 

Anaplasmosis, Babesiosis , Ehrlichiosis, Lyme disease, Rickettsia parkeri Rickettsiosis, Rocky Mountain Spotted Fever (RMSF), STARI (Southern Tick-Associated Rash Illness), Tickborne relapsing fever (TBRF), Tularemia, and 364D Rickettsiosis.

And last year in New Phlebovirus Discovered In Missouri we learned of another emerging virus carried by ticks, dubbed the `Heartland Virus’.

 

 

Whether a new and emerging threat, or simply noticed now due to our ability to recognize a long-time nemesis – without a vaccine – your best bet is to avoid infection. So it makes sense to take precautions against ticks and other vector-borne diseases.

 

This from the Minnesota Department of Health.

 

Lastly, the CDC offers advice on:

 

Preventing Tick Bites

While it is a good idea to take preventive measures against ticks year-round, be extra vigilant in warmer months (April-September) when ticks are most active.

Japan Announces 4th SFTS Fatality

 

Photo Credit Wikipedia Tick Species Associated with SFTS in China

# 6952

 

 

SFTS or Severe Fever with thrombocytopenia syndrome emerged as a diagnosis in China after outbreaks were identified in Hubei and Henan provinces during the spring and summer of 2009.  While ticks were suspected as vectors, the pathogen behind this disease was not initially known.

 

In 2011, the NEJM published a study Fever with Thrombocytopenia Associated with a Novel Bunyavirus in China.  STFS has been associated with a 12% mortality rate in China.

 

To date over three hundred Bunyaviruses have been identified, with rodents often cited as carriers. While not all Bunyaviruses are dangerous to humans (some only infect plants), the Bunyavirus family include such nasties as Crimean-Congo hemorrhagic fever, Hantaviruses, and Rift Valley Fever.

 

Most are spread via arthropod vectors (ticks, mosquitoes & sand flies), with the exception of Hantaviruses (see Hantaviruses Revisited), which are spread via the feces and urine of rodents.

 

Just three weeks ago (see SFTS Fatality Reported In Japan) we learned of the first known SFTS case in the country of Japan. Just two weeks later, headlines read Japan Reports Two Additional SFTS Fatalities.

 

Today, news of a 4th confirmed fatality in Japan, and word that 9 more cases are under investigation.  Links to two news report and a Japan Ministry of Health Statement, and then I’ll return with a little more.

 

Tick-borne virus claimed 4th victim last summer

Jiji Press

A man died in Hiroshima Prefecture last summer after being infected with a tick-borne virus, becoming the fourth known victim of the viral infection in the country, the health ministry said Tuesday

(Continue . . .)

 

 

Concern rises over deadly tick-borne virus in Japan

February 20, 2013

THE ASAHI SHIMBUN

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 first surfaced in China.

 

(Continue . . . )

 

 

From Japan’s Ministry of Health (warning, awkward machine translation ahead).

 

Situation in the country confirmed thrombocytopenia syndrome in patients with severe febrile (SFTS)

Recently, "syndrome thrombocytopenia febrile severe (Severe Fever with Thrombocytopenia Syndrome: SFTS)" disease tickborne new response to the fact that cases have been confirmed for the first time in the country, with respect to medical institutions, we have examined the patient similar If you provide information that has been requested through the local government cooperation (Annex 1).

Then out of the case, written by a medical institution, it was a SFTS is confirmed by inspection of the National Institute of Infectious Diseases (. suspected domestic infection. died last summer. Hiroshima adult males) one new case Since, in municipalities across the country that I have provided information effect (Annex 2).
Continue to conduct research and gather information about the disease, in the Ministry of Health, Labour and Welfare, we will take appropriate action.

 

While the sudden identification of 4 fatal cases linked to a recently discovered virus may be a bit disconcerting, it doesn’t necessarily indicate a new threat has emerged on the Japanese landscape. 

 

Often detections of a novel infectious disease come about as the inevitable result of better diagnostic tests that can now identify pathogens that - until recently - were misidentified or missed altogether.

 

Tickborne diseases are on the rise in the United States and around the world, with Lyme disease alone blamed for 20,000+ infections each year (MMWR Lyme Disease --- United States, 2003—2005).

The CDC lists a number of diseases carried by ticks in the United States, including: Anaplasmosis, Babesiosis , Ehrlichiosis, Lyme disease, Rickettsia parkeri Rickettsiosis, Rocky Mountain Spotted Fever (RMSF), STARI (Southern Tick-Associated Rash Illness), Tickborne relapsing fever (TBRF), Tularemia, and 364D Rickettsiosis.

 

And last year in  New Phlebovirus Discovered In Missouri we learned of another emerging virus carried by ticks, dubbed the `Heartland Virus’.

 

Whether a new and emerging threat, or simply our ability to finally recognize a long-time nemesis, it makes sense to take precautions against ticks and other vector-borne diseases.

 

This from the Minnesota Department of Health.

Lastly, the CDC offers advice on:

 

Preventing Tick Bites

While it is a good idea to take preventive measures against ticks year-round, be extra vigilant in warmer months (April-September) when ticks are most active.

Japan Reports Two Additional SFTS Fatalities

 

Photo Credit Wikipedia

Tick Species Associated with SFTS in China

 

 

# 6933

 

Two weeks ago, in SFTS Fatality Reported In Japan, we learned of the first known case of SFTS (Severe Fever with thrombocytopenia syndrome) recorded in Japan, linked to a tickborne Bunyavirus virus recently discovered in China.

 

Photo Credit Wikipedia

 

Outbreaks of this syndrome were first identified in central China's Hubei and Henan provinces during the spring and summer of 2009.

 

In 2011, the NEJM carried a report: Fever with Thrombocytopenia Associated with a Novel Bunyavirus in China that linked the syndrome to a novel virus.

 

At that time, human-to-human transmission of the virus was not suspected, but that changed with the 2012 publication of an article in the journal Vector Borne Zoonotic Diseases called:

Person-to-person transmission of severe fever with thrombocytopenia syndrome virus.

Liu Y, Li Q, Hu W, Wu J, Wang Y, Mei L, Walker DH, Ren J, Wang Y, Yu XJ.

(Excerpt)

We concluded that SFTSV can be transmitted from person to person through contacting patient's blood.

 

Today, thanks to a tip from a reader in Japan, we learn that two more cases of SFTS have been identified in Japan.

 

From NHK World News.

 

Tick-transmitted virus killed 2 more last year

Feb. 13, 2013 - Updated 06:51 UTC (15:51 JST)

Japanese health authorities have confirmed 2 more deaths last year from a tick-transmitted virus in western Japan.

 

In January, the health ministry confirmed that a woman in Yamaguchi Prefecture died last autumn of severe fever with thrombocytopenia syndrome, or SFTS.

 

The death was the first confirmed in Japan from the infectious disease, which has a 12 percent fatality rate. The virus that causes SFTS was identified in China in 2011.

 

Japan's National Institute of Infectious Diseases says 2 more patients, both adult males in Ehime and Miyazaki prefectures, also died of SFTS last year.

 

Neither man had traveled abroad before falling ill.
The viruses detected in the patients were genetically similar to the one found in Yamaguchi Prefecture but not those in China.

 

Health officials believe the 2 men were infected with the virus from tick bites in Japan. The virus-carrying ticks live outdoors and are of a different type from those found in clothing and bed

 

And another report the Daily Mainichi.

 

2 more Japanese confirmed dead due to new viral infection

TOKYO (Kyodo) -- The health ministry said Wednesday two more Japanese had been confirmed dead due to a new viral infection transmitted by a mite bite, bringing the death toll to three in the country.

(Continue . . .)

 

 

This brings to three the number of cases reported in Japan, and they all occurred in people without recent travel history out of the country, and in three separate prefectures.

From Japan’s Ministry of Health we get the following (albeit awkwardly machine translated) statement:

 

Situation in the country confirmed thrombocytopenia syndrome in patients with severe febrile (SFTS)

Recently, "syndrome thrombocytopenia febrile severe (Severe Fever with Thrombocytopenia Syndrome: SFTS)" disease tickborne new response to the fact that cases have been confirmed for the first time in the country, with respect to medical institutions, we have examined the patient similar If you provide information that has been requested through the local government cooperation (Annex 1).

 

Thing out of the case then, written by a medical institution, (died last fall either. male adults in Miyazaki Prefecture and adult men, Ehime Prefecture. no history of travel abroad these days) two cases were SFTS for infection National Since the disease is confirmed by laboratory tests, to local governments across the country that I have provided information effect (Annex 2).

 

Continue to conduct research and gather information about the disease, in the Ministry of Health, Labour and Welfare, we will take appropriate action.

SFTS Fatality Reported In Japan

Photo Credit Wikipedia

# 6899

 

 

Having recently read David Quammen’s terrific book on emerging infectious diseases called `Spillover’ (see EID Book Review – Spillover), I may be hyper-sensitized to any odd reports of newly emerging pathogens.

 

Nevertheless, this next story – which involves a recently discovered virus showing up in a new country  –  is unusual enough to merit mention.

 

Today the Mainichi is reporting that a Japanese adult – without recent travel history outside of the country – died last fall from a recently discovered viral infection called SFTS (Severe Fever with thrombocytopenia syndrome) that until now, has only been seen in China.

 

SFTS – linked to a recently discovered Bunyavirus - is believed to be transmitted primarily by ticks. Outbreaks were first identified in central China's Hubei and Henan provinces during the spring and summer of 2009.

 

We got our first real look at this syndrome from the NEJM in 2011 (see Fever with Thrombocytopenia Associated with a Novel Bunyavirus in China).  At that time, they stated `There was no epidemiologic evidence of human-to-human transmission of the virus.’

For more details on that NEJM report, I would invite you to read Lisa Schnirring’s excellent summary for CIDRAP NEWS  (Chinese researchers link febrile disease to new virus).

 

Since then, in February of 2012, the journal Vector Borne Zoonotic Diseases carried this game-changing report:

 

Person-to-person transmission of severe fever with thrombocytopenia syndrome virus.

 

Liu Y, Li Q, Hu W, Wu J, Wang Y, Mei L, Walker DH, Ren J, Wang Y, Yu XJ.

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by a newly discovered bunyavirus, SFTS virus (SFTSV), and causes high fatality (12% on average and as high as 30%). The objective of this study was to determine whether SFTSV could be transmitted from person to person.

 

We analyzed sera of 13 patients from two clusters of unknown infectious diseases that occurred between September and November of 2006 in Anhui Province of China for SFTSV antibody by indirect immunofluorescence assay and for SFTSV RNA by RT-PCR. We found that all patients (n=14) had typical clinical symptoms of SFTS including fever, thrombocytopenia, and leukopenia and all secondary patients in both clusters got sick at 6-13 days after contacting or exposing to blood of index patients.

 

We demonstrated that all patients in cluster 1 including the index patient and nine secondary patients and all three secondary patients in cluster 2 had seroconversion or fourfold increases in antibody titer to SFTSV and/or by RT-PCR amplification of SFTSV RNA from the acute serum. The index patient in cluster 2 was not analyzed because of lack of serum. No person who contacted the index patient during the same period, but were not exposed to the index patient blood, had got illness.

 

We concluded that SFTSV can be transmitted from person to person through contacting patient's blood.

 

The question now is how did an adult male in Japan contract this never-reported-before-in-Japan virus? 

 

One might surmise that he came in contact with the blood of an infected individual who had recently visited China . . .  but today’s report states that:

 

Genetic studies show the virus that killed the Japanese occurred in Japan and did not come from China, the ministry said.

 

Which if correct, creates a bit of an epidemiological puzzle for public health experts to investigate.

 

Note: A h/t to Makoto on Twitter for the link.