The discovery of an emerging viral disease, severe fever with thrombocytopenia syndrome (SFTS), caused by SFTS virus (SFTSV), has prompted the need to understand pathogenesis of SFTSV. We are unique in establishing an infectious model of SFTS in C57/BL6 mice, resulting in hallmark symptoms of thrombocytopenia and leukocytopenia. Viral RNA and histopathological changes were identified in the spleen, liver, and kidney. However, viral replication was only found in the spleen, which suggested the spleen to be the principle target organ of SFTSV. Moreover, the number of macrophages and platelets were largely increased in the spleen, and SFTSV colocalized with platelets in cytoplasm of macrophages in the red pulp of the spleen. In vitro cellular assays further revealed that SFTSV adhered to mouse platelets and facilitated the phagocytosis of platelets by mouse primary macrophages, which in combination with in vivo findings, suggests that SFTSV-induced thrombocytopenia is caused by clearance of circulating virus-bound platelets by splenic macrophages. Thus, this study has elucidated the pathogenic mechanisms of thrombocytopenia in a mouse model resembling human SFTS disease.animal model | phlebovirus | pathology | reduction of platelets | macrophage infection S evere fever with thrombocytopenia syndrome (SFTS) is a recently identified emerging viral infectious disease in China that is caused by a novel phlebovirus in the family Bunyaviridae, SFTS virus (SFTSV) (1). Clinical features of SFTS patients include abrupt high fever, thrombocytopenia, leukocytopenia, and gastrointestinal symptoms. Laboratory tests commonly show elevated serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), lactate dehydrogenase, creatine kinase, creatine kinase MB fraction, as well as elongated activated partial-thromboplastin time (1). These abnormally changed laboratory parameters are indicative of the pathological lesions that occur in multiple organs and altered homeostasis of the coagulation systems of SFTS patients. Pathological studies of SFTS are absent because patient tissues are rarely donated after death in rural areas of China. Therefore, the causes of illness and death, as well as pathological changes within organs, remain unclear. To systematically investigate the pathogenic mechanisms of SFTS and understand key symptoms, such as thrombocytopenia, infectious animal models for SFTSV are urgently needed. ResultsEstablishment of a SFTSV Pathogenic Mouse Model. In our initial study, to identify an infectious animal model that could mimic most clinical features during SFTSV infection, the susceptibilities of three commonly used laboratory rodent strains for phlebovirus (2-4), C57/BL6 mice, BalB/C mice, and Syrian hamsters, were examined. The SFTSV strain HB29 was inoculated at 10 5 TCID 50 (50% tissue culture infective dose) per mouse or 5 × 10 5 TCID 50 per hamster through four different routes of infection, including intravenous, intramuscular, intraperitoneal, and intracerebral...

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In 2013, a resurgence of measles occurred in Beijing, China. The outbreaks occurred among adults and were associated with endemic genotype H1 and imported genotype D8 viruses. Migrant workers were disproportionately represented in the outbreaks; thus, vaccinating such workers against measles may be an effective strategy toward the elimination of this disease.

Public housing (PH) has existed in Hong Kong for six decades. Previous and current challenges that have been encountered over time function as a collective driver for design progression. However, such challenges have remained under research to be able to draw useful lessons from them. To understand how this established motif can suit the sustainability-conscious era, this study uses Hong Kong as a representative case for sub-tropical compact cities by critiquing its PH design against multiple constraints. The objective of this study is to trace the historical relationships between challenges and design progress as well as to assess current and future implications of sustainability trends on PH design. By synthesizing data from literature, policy documents, and empirical evidence, this research develops an evolution map for PH design in Hong Kong that is driven by seven major challenges. Based on this map, a conceptual framework for intersecting considerations that envisages five main future prospects toward future PH design is also established.

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