Severe Fever with Thrombocytopenia Syndrome (SFTS)


Background
Severe Fever with Thrombocytopenia Syndrome (SFTS), an emerging infectious disease, is first reported in China in 2011. SFTS is caused by the virus (Severe Fever with Thrombocytopenia Syndrome virus, SFTSV) and is transmitted to humans through the bite of an infected tick. In Taiwan, the first confirmed case of SFTS was reported in 2019.
In the first week after the onset of illness, most patients have symptoms such as fever, low platelet count and leukopenia, and may also have symptoms such as nausea, vomiting, diarrhea, headache, muscle pain, lymphatic enlargement, and bleeding. In the second week after the onset, multiple organ failures such as liver and kidney or diffuse intravascular coagulation abnormalities may occur. In the third week, most patients will recover from the disease, and a small number of severely ill patients may die. The fatality rate is about 5-15%.

Epidemiology
The prevalence of SFTS has been monitored in China since October 2010. A total of 5,360 cases were confirmed in 2016, mainly in the central regions of Shandong, Jiangsu, Anhui, Henan, Hubei, Zhejiang and Liaoning. Japan has reported SFTS cases since 2013. As of December 30, 2020, there were a total of 573 confirmed cases and a total of 75 deaths (the fatality rate: 13.1%). The cases were mainly reported in the west and south of Japan. South Korea has also had SFTS cases since 2013. In 2019, there were a total of 223 confirmed cases, of which 41 were fatal cases (the fatality rate 18.4%). The cases were mostly in northern Gangwon-do and Gyeonggi-do.

Severe Fever with Thrombocytopenia Syndrome Surveillance in Taiwan

  1. Taiwan National Infectious Disease Statistics System–SFTS
  2. Self–reporting through the toll–free 1922 hotline or local public health authority.

Prevention and Control
  1. Prevention measures to be taken when visiting affected areas or outdoor to ward off infection are listed below.
    (1) Wearing protective clothing such as long–sleeved shirts, pants, gloves and boots, tucking pants into socks.
    (2) Insect repellents can be applied to the skin and clothing to prevent tick bites.
    (3) Change clothes and taking a shower immediately after a visit to the bush area to reduce the risk of infection.
  2. If a tick is found attached to the skin, please promptly remove the tick using fine–tipped tweezers with caution to prevent causing the mouth–parts to break off and remaining in the skin, and clean the bite site using soap and water to lower the risk of infection.

FAQs
  1. How is the SFTS transmitted?
    SFTS is transmitted to humans by the bite of infected ticks. In addition, transmission of SFTSV between humans through direct contact with infected blood has been reported.
  2. What are the clinical symptoms of SFTS?
    The primary symptoms include fever, fatigue, loss of appetite, nausea, vomiting, thrombocytopenia (low platelet count), and leukopenia (low white blood cell count). In severe cases, hemorrhage, multiple organ failure and even death may occur. The case fatality rate is approximately 5-15%
  3. Who is at risk of SFTS?
    Those people visiting in endemic areas, grasses, woods and other outdoor environments, might be bitten by infected ticks. Epidemiological data from China, Japan, and South Korea show that the high-risk groups are farmers and the elderly population.
  4. How to remove a tick?
    (1) Use fine–tipped tweezers to grasp the tick as close to the skin surface as possible.
    (2) Pull upward with steady, even pressure. Don't twist or jerk the tick; this can cause the mouth–parts to break off and remain in the skin. If this happens, remove the mouth–parts with tweezers. If you are unable to remove the mouth easily with clean tweezers, leave it alone and let the skin heal.
    (3) After removing the tick, thoroughly clean the bite area and your hands with rubbing alcohol, an iodine scrub, or soap and water.
    (4) Dispose of a live tick by submersing it in alcohol, placing it in a sealed bag/container, wrapping it tightly in tape, or flushing it down the toilet. Never crush a tick with your fingers.
  5. What is the treatment for STFS?
    There is no specific medication for treatment of a STFS infection. If you have suspected STFS symptoms, please seek medical attention immediately and inform the physician of the history of tick bites, the history of outdoor activities in epidemic areas, or the history of activities in such brush area.
  6. Does a patient with STFS need to be hospitalized in isolation?
    A patient reported as a suspected case of STFS must be placed in a single isolation room for treatment. If the patient tests negative for the virus, the patient will be released from isolation; a patient with confirmed infection will be released from isolation after the results of the PCR test of the serum specimen are negative for two consecutive times (24 hours apart).
More Information
  1. JAPAN NIID|SFTS
  2. KCDC|SFTS

發佈日期 2021/5/18