A cluster of cases of severe fever with thrombocytopenia syndrome bunyavirus infection in China, 1996: A retrospective serological study

Abstract

BackgroundA cluster of eleven patients, including eight family members and three healthcare workers with fever and thrombocytopenia occurred in Yixing County, Jiangsu Province, China, from October to November 1996. However, the initial investigation failed to identify its etiology. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS bunyavirus (SFTSV), which was first discovered in 2009. The discovery of novel SFTSV resulted in our consideration to test SFTSV on the remaining samples of this cluster in September 2010.Methodology/Principal findingsWe retrospectively analyzed the epidemiological and clinical data of this cluster. The first case, one 55-year-old man with fulminant hemorrhagic diseases, died on October 14, 1996. His younger brother (the second case) developed similar hemorrhagic diseases after nursing him and then died on November 3. From November 4 to November 15, nine other patients, including six family members and three medical staffs, developed fever and thrombocytopenia after exposure to the second case. The sera of six patients were collected on November 24, 1996. IgM antibodies against SFTSV were detected in all of the six patients’ sera using enzyme-linked immunosorbent assay (ELISA), while IgG antibodies were detected in one patient’s serum using an indirect immunofluorescence assay (IFA). We also found that IgG antibodies against SFTSV were still detected in four surviving patients’ sera 14 years after illness onset.Conclusions and significanceThe mysterious pathogen of the cluster in 1996 was proved to be SFTSV on the basis of its epidemiological data, clinical data and serological results. It suggests that SFTSV has been circulating in China for more than 10 years before being identified in 2009, and SFTSV IgG antibodies can persist for up to 14 years.

Spatial-temporal characteristics of severe fever with thrombocytopenia syndrome and the relationship with meteorological factors from 2011 to 2018 in Zhejiang Province, China

“…Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever caused by the severe fever with thrombocytopenia syndrome virus (SFTSV), which is classified in the order Bunyavirales, family Phenuiviridae, and genus Phlebovirus [1][2][3]. SFTS was first confirmed among rural areas in China in 2009 and subsequently reported in North Korea in 2009, South Korea in 2012 and Japan in 2013 [4][5][6][7].…”

“…Furthermore, a cluster of cases of SFTS in 1996 was uncovered and reported in a new study. It has been suggested that the SFTSV has been circulating in China for more than 10 years prior to 2009 [2]. An SFTSV-like virus called the Heartland virus was also isolated in the United States in 2012 [8].…”

“…The main clinical symptoms of SFTS include fever, thrombocytopenia, leukocytopenia, gastrointestinal symptoms, neurological symptoms and bleeding tendency, as well as less specific clinical manifestations [9,10]. The average case fatality rate typically varies from 8% to 12% [2,11], but it can reach 32.6% [12,13].…”

“…SFTS was listed as one of the nine most infectious diseases on the WHO priority list in 2017 [2]. This disease is a severe public health issue in mainland China, and approximately 90% of worldwide cases have been reported from China [4].…”

Severe Fever with Thrombocytopenia Syndrome Virus Infection or Mixed Infection with Scrub Typhus in South Korea in 2000–2003

“…1 Severe fever with thrombocytopenia syndrome (SFTS) was first confirmed in China in 2009, and retrospective serological studies showed that SFTSV-specific IgM and IgG were detected in the sera of patients in China in 1996 and retrospectively reported in South Korea in 2010, in Japan in 2013, and in Vietnam in 2017. [2][3][4][5][6] Most SFTSV infections occur through bites from the tick Haemaphysalis longicornis, although SFTSV transmission can also occur through close contact with an infected patient. [2][3][4][5][6][7][8][9][10][11] Scrub typhus is a bacterial disease caused by Orientia tsutsugamushi that is transmitted primarily by the bite of the Leptotrombidium spp.…”