Severe fever with thrombocytopenia syndrome (SFTS) is a
tick-borne infection caused by ''
Dabie bandavirus'' also known as the SFTS virus, first reported between late March and mid-July 2009 in rural areas of Hubei and Henan provinces in Central China.
It is an
emerging infectious disease
An emerging infectious disease (EID) refer to infectious diseases that have either newly appeared in a population or have existed but are rapidly increasing in incidence, geographic range, or severity due to factors such as environmental change ...
causing fever, vomiting, diarrhea, loss of consciousness and heamorrhage.
[
SFTS has fatality rates ranging from 12% to as high as 30% in some areas due to ]multiple organ failure
Multiple organ dysfunction syndrome (MODS) is altered organ function in an acutely ill patient requiring immediate medical intervention.
There are different stages of organ dysfunction for certain different organs, both in acute and in chronic ...
, thrombocytopenia
In hematology, thrombocytopenia is a condition characterized by abnormally low levels of platelets (also known as thrombocytes) in the blood. Low levels of platelets in turn may lead to prolonged or excessive bleeding. It is the most common coag ...
(low platelet count), leucopenia
Leukopenia () is a decrease in the number of white blood cells (leukocytes). It places individuals at increased risk of infection as white blood cells are the body's primary defense against infections.
Signs and symptoms
Symptoms may include:
* sk ...
(low white blood cell count), and elevated liver enzyme levels.
Virology
SFTS virus (SFTSV) is a virus in the order ''Bunyavirales
''Bunyaviricetes'' is a class of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. The name ''Bunyaviricetes'' derives from Bunyamwera, where the virus Bun ...
'', discovered in 2009.
Transmission
The life cycle of the SFTSV most likely involves arthropod
Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
vectors like '' Haemaphysalis longicornis'' tick
Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...
s and animal hosts. Humans appear to be largely accidental hosts.
Person-to-person transmission was not initially noted in the 2011, but occurs via blood or mucus as documented in 2012.
Symptoms and signs
SFTS is an emerging infectious disease
An emerging infectious disease (EID) refer to infectious diseases that have either newly appeared in a population or have existed but are rapidly increasing in incidence, geographic range, or severity due to factors such as environmental change ...
causing fever, vomiting, diarrhea, loss of consciousness and heamorrhage.[
SFTS has fatality rates ranging from 12% to as high as 30% in some areas due to ]multiple organ failure
Multiple organ dysfunction syndrome (MODS) is altered organ function in an acutely ill patient requiring immediate medical intervention.
There are different stages of organ dysfunction for certain different organs, both in acute and in chronic ...
, thrombocytopenia
In hematology, thrombocytopenia is a condition characterized by abnormally low levels of platelets (also known as thrombocytes) in the blood. Low levels of platelets in turn may lead to prolonged or excessive bleeding. It is the most common coag ...
(low platelet count), leucopenia
Leukopenia () is a decrease in the number of white blood cells (leukocytes). It places individuals at increased risk of infection as white blood cells are the body's primary defense against infections.
Signs and symptoms
Symptoms may include:
* sk ...
(low white blood cell count), and elevated liver enzyme levels.
In July 2013, South Korea reported a total of eight deaths since August 2012.
In July 2017, Japanese doctors reported that a woman had died of SFTS after being bitten by a cat that may have itself been infected by a tick. The woman had no visible tick bites, leading doctors to believe that the cat — which died as well — was the transmission vector.
Epidemiology
SFTS occurs in China's rural areas from March to November with the majority of cases from April to July. In 2013, Japan and Korea also reported several cases with deaths.
In early 2020 an outbreak occurred in East China
East China () is a geographical region in the People’s Republic of China, mainly consisting of seven province-level administrative divisions, namely the provinces (from north to south) Shandong, Jiangsu, Anhui, Zhejiang, Jiangxi, Fujian, ...
, more than 37 people were found with SFTS in Jiangsu province, while 23 more were found infected in Anhui province in August 2020. Seven people have died.Seven dead, 60 infected by new infectious disease in China: Report
7 August 2020 ''indianexpress.com'', accessed 24 October 2020
References
External links
{{Tick-borne diseases and infestations
Arthropod-borne viral fevers and viral haemorrhagic fevers
Insect-borne diseases
Zoonotic viral diseases