Severe Fever with Thrombocytopenia Syndrome Phlebovirus causes lethal viral hemorrhagic fever in cats

Abstract

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever caused by the SFTS phlebovirus (SFTSV). SFTS patients were first reported in China, followed by Japan and South Korea. In 2017, cats were diagnosed with SFTS for the first time, suggesting that these animals are susceptible to SFTSV. To confirm whether or not cats were indeed susceptible to SFTSV, animal subjects were experimentally infected with SFTSV. Four of the six cats infected with the SPL010 strain of SFTSV died, all showing similar or more severe symptoms than human SFTS patients, such as a fever, leukocytopenia, thrombocytopenia, weight loss, anorexia, jaundice and depression. High levels of SFTSV RNA loads were detected in the serum, eye swab, saliva, rectal swab and urine, indicating a risk of direct human infection from SFTS-infected animals. Histopathologically, acute necrotizing lymphadenitis and hemophagocytosis were prominent in the lymph nodes and spleen. Severe hemorrhaging was observed throughout the gastrointestinal tract. B cell lineage cells with MUM-1 and CD20, but not Pax-5 in the lesions were predominantly infected with SFTSV. The present study demonstrated that cats were highly susceptible to SFTSV. The risk of direct infection from SFTS-infected cats to humans should therefore be considered.

The Severe Fever with Thrombocytopenia Syndrome Virus NSs Protein Interacts with CDK1 To Induce G 2 Cell Cycle Arrest and Positively Regulate Viral Replication

“…In contrast, SFTSV NSs is expressed in the cytoplasm, where it forms IBs that sequester various regulatory proteins, which may change the distribution of (and therefore interfere with the function of) cell cycle regulatory proteins (21,54,55). Although SFTSV and RVFV belong to the family Phenuiviridae (13,56,57), our data show that G 2 /M arrest is conducive to SFTSV replication, while previous data show that S-phase blockade promotes RVFV proliferation. Although both SFTSV and RVFV cause changes in the host cell cycle, the processes and outcomes are different, which may explain why SFTSV and RVFV have different prevalence and pathogenic characteristics.…”

Severe Fever with Thrombocytopenia Syndrome, Japan, 2013–2017

“…High fever (>39.5°C) was noted in 15/22 cats (68.2%) and vomiting in 10/24 cats (41.7). Animal experiments by Park et al (31) confirmed that cats are susceptible to SFTSV infection; the authors reported that 4/6 cats infected with SFTSV died, and all cats showed signs that were similar to or more severe than those signs observed in humans infected with SFTSV. Those authors also found high viral loads in serum, saliva, and eye swabs taken 7 days postinfection from cats that subsequently died from infection.…”

Development of a reverse transcription polymerase chain reaction for the detection of severe fever with thrombocytopenia syndrome virus from suspected infected animals

“…The serum specimens of the cats were collected within one week after the onset. Given that the level of neutralizing antibodies in the surviving cats was elevated in our previous study [8], the insufficient induction or non-function of neutralizing antibodies might result in the severe onset in cats. Given that B cell lineages, such as plasmablasts, can be the target of SFTSV, this may be a plausible result.…”

“…Furthermore, it has been shown that cheetahs [7], cats [8] and dogs can contract SFTS (manuscript in preparation). Thus, it is important to diagnose SFTS-suspected animals.…”