Roles of raccoons in the transmission cycle of severe fever with thrombocytopenia syndrome virus

The present study investigated severe fever with thrombocytopenia syndrome virus (SFTSV) infection in raccoons in Wakayama Prefecture from 2007 to 2019. To perform surveillance, an enzyme-linked immunosorbent assay (ELISA) was established, and the sensitivity and specificity of the ELISA were 100% in comparison with a 50% focus-reduction neutralization assay. Using the established ELISA, we performed serosurveillance of SFTSV infection in 2,299 raccoons in Tanabe region, Wakayama Prefecture from 2007 to 2019. The first anti-SFTSV-positive raccoon was captured in October 2009. The seroprevalence of SFTSV infection was <10% between April 2009 and March 2013, 23.9% between April 2013 and March 2014, 37.5% between April, 2014 and March 2015, and over 50% from April 2015. Next, we performed detection of SFTSV genes in sera of raccoons captured in Wakayama Prefecture after April 2013. The results indicated that 2.4% of raccoons were positive for SFTSV genes and that the frequency of SFTSV infection among raccoons between January and March (0.7%) was lower than that between April and June (3.4%). In addition, virus genes were detected from many specimens, including sera and feces of two raccoons, and viral antigens were detected in lymphoid cells in lymphoid follicles in the colon by immunohistochemical staining. In conclusion, SFTSV had recently invaded the area and had rapidly spread among wild animals. The first patient in this area was reported in June 2014, indicating that raccoons are good sentinels for assessing the risk of SFTSV in humans.

[1]  T. Nabeshima,et al.  Severe Fever with Thrombocytopenia Syndrome in Cats and Its Prevalence among Veterinarian Staff Members in Nagasaki, Japan , 2021, Viruses.

[2]  Y. Choi,et al.  Severe fever with thrombocytopenia syndrome virus: emerging novel phlebovirus and their control strategy , 2021, Experimental & Molecular Medicine.

[3]  M. Shimojima,et al.  Diagnostic system for the detection of severe fever with thrombocytopenia syndrome virus RNA from suspected infected animals , 2021, PloS one.

[4]  M. Shimojima,et al.  Severe Fever with Thrombocytopenia Syndrome, Japan, 2013–2017 , 2020, Emerging infectious diseases.

[5]  H. Shimoda,et al.  The first discovery of severe fever with thrombocytopenia syndrome virus in Taiwan , 2020, Emerging microbes & infections.

[6]  M. Shimojima,et al.  Severe Fever with Thrombocytopenia Syndrome Phlebovirus causes lethal viral hemorrhagic fever in cats , 2019, Scientific Reports.

[7]  K. Maeda,et al.  Natural severe fever with thrombocytopenia syndrome virus infection in domestic cats in Japan. , 2019, Veterinary microbiology.

[8]  Xuan Chuong Tran,et al.  Endemic Severe Fever with Thrombocytopenia Syndrome, Vietnam , 2019, Emerging infectious diseases.

[9]  Xi Cheng,et al.  Animals as amplification hosts in the spread of severe fever with thrombocytopenia syndrome virus: A systematic review and meta-analysis. , 2019, International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases.

[10]  M. Shimojima,et al.  Seroprevalence of severe fever with thrombocytopenia syndrome (SFTS) virus antibodies in humans and animals in Ehime prefecture, Japan, an endemic region of SFTS. , 2018, Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy.

[11]  A. Takada,et al.  Fatal Tickborne Phlebovirus Infection in Captive Cheetahs, Japan , 2018, Emerging infectious diseases.

[12]  M. Shimojima,et al.  A neutralization assay with a severe fever with thrombocytopenia syndrome virus strain that makes plaques in inoculated cells. , 2017, Journal of virological methods.

[13]  Y. Miyasako,et al.  Severe Fever with Thrombocytopenia Syndrome , 2016, Internal medicine.

[14]  M. Shimojima,et al.  Epidemiological and Clinical Features of Severe Fever with Thrombocytopenia Syndrome in Japan, 2013–2014 , 2016, PloS one.

[15]  M. Oh,et al.  Detection of Severe Fever with Thrombocytopenia Syndrome Virus from Wild Animals and Ixodidae Ticks in the Republic of Korea. , 2016, Vector borne and zoonotic diseases.

[16]  Guillermo Posadas-Herrera,et al.  Seroepidemiological evidence of severe fever with thrombocytopenia syndrome virus infections in wild boars in Nagasaki, Japan , 2016, Tropical Medicine and Health.

[17]  Zheng Xing,et al.  Ecology of the Tick-Borne Phlebovirus Causing Severe Fever with Thrombocytopenia Syndrome in an Endemic Area of China , 2016, PLoS neglected tropical diseases.

[18]  M. Shimojima,et al.  Severe Fever with Thrombocytopenia Syndrome Virus Antigen Detection Using Monoclonal Antibodies to the Nucleocapsid Protein , 2016, PLoS neglected tropical diseases.

[19]  Sudhir Kumar,et al.  MEGA7: Molecular Evolutionary Genetics Analysis Version 7.0 for Bigger Datasets. , 2016, Molecular biology and evolution.

[20]  Haruo Watanabe,et al.  Efficacy of T-705 (Favipiravir) in the Treatment of Infections with Lethal Severe Fever with Thrombocytopenia Syndrome Virus , 2016, mSphere.

[21]  M. Shimojima,et al.  Phylogenetic and Geographic Relationships of Severe Fever With Thrombocytopenia Syndrome Virus in China, South Korea, and Japan. , 2015, The Journal of infectious diseases.

[22]  Yeojun Yun,et al.  Phylogenetic Analysis of Severe Fever with Thrombocytopenia Syndrome Virus in South Korea and Migratory Bird Routes Between China, South Korea, and Japan. , 2015, The American journal of tropical medicine and hygiene.

[23]  H. Shimoda,et al.  Canine distemper virus infection among wildlife before and after the epidemic , 2015, The Journal of veterinary medical science.

[24]  Z. Bi,et al.  SFTS virus in ticks in an endemic area of China. , 2015, The American journal of tropical medicine and hygiene.

[25]  M. Shimojima,et al.  Mild Clinical Course of Severe Fever with Thrombocytopenia Syndrome Virus Infection in an Elderly Japanese Patient , 2014, Case reports in infectious diseases.

[26]  M. Han,et al.  Severe Fever with Thrombocytopenia Syndrome Virus, South Korea, 2013 , 2014, Emerging infectious diseases.

[27]  M. Shimojima,et al.  The First Identification and Retrospective Study of Severe Fever With Thrombocytopenia Syndrome in Japan , 2013, The Journal of infectious diseases.

[28]  Zheng Xing,et al.  Severe Fever with Thrombocytopenia Syndrome Virus among Domesticated Animals, China , 2013, Emerging infectious diseases.

[29]  S. Ding,et al.  Clinical and epidemiological study on severe fever with thrombocytopenia syndrome in Yiyuan County, Shandong Province, China. , 2013, The American journal of tropical medicine and hygiene.

[30]  Y. Kanda,et al.  Investigation of the freely available easy-to-use software ‘EZR' for medical statistics , 2012, Bone Marrow Transplantation.

[31]  M. Shimojima,et al.  [Severe fever with thrombocytopenia syndrome in Japan]. , 2013, Uirusu.

[32]  Qun Li,et al.  Person-to-person transmission of severe fever with thrombocytopenia syndrome virus. , 2012, Vector borne and zoonotic diseases.

[33]  Weizhong Yang,et al.  Fever with thrombocytopenia associated with a novel bunyavirus in China. , 2011, The New England journal of medicine.