Modeling population-wide testing of SARS-CoV-2 for containing COVID-19 pandemic in Okinawa, Japan

To break the chains of SARS-CoV-2 transmission and contain the coronavirus disease 2019 (COVID-19) pandemic, population-wide testing has been practiced in various countries. However, scant research has addressed this topic in Japan. In this modeling exercise, we extracted the number of daily reported cases of COVID-19 in Okinawa from October 1 to November 30, 2020, and explored possible scenarios for decreasing COVID-19 incidence by combining population-wide screening and/or social distancing policy. We reveal that permanent lockdown can be theoretically replaced by mass testing but sufficient target population at an adequate frequency must be mobilized. In addition, solely imposing a circuit breaker will not bring a favorable outcome in the long run, and mass testing presents implications for minimizing a period of lockdown. Our results highlight the importance of incentivizing citizens to join the frequent testing and ensure their appropriate isolation. This study also suggests that early containment of COVID-19 will be feasible in prefectures where the mobility is low and/or can be easily controlled for its geographic characteristics. Rigorous investment in public health will be manifestly vital to contain COVID-19

Salmonella Contamination of Rivers and Sewages in Fukuyama City

地方都市におけるサルモネラによる環境汚染の実態を知る目的で，昭和41・42年に広島県東部地区福山市における河水，下水などを対象としてサルモネラの検索を行なった.その結果，以下のような成績が得られた. 1. サルモネラ陽性率は河水が23.6% (13/55)，下水が22.2% (8/36)，と場汚水が36.8% (7/19)の成績であった. 2. これらの陽性率は，東京，大阪など大都市における河川および下水のサルモネラ陽性率に比べると，まだ低い状況にある. 3. 28例の陽性検体から分離された33株の血清型は，S. derby，S. typhimurium，S. montevideo，S. thompson，S. mikawashima，S. narashino，S. enteritidis，S. meleagridis，S. give，S. senftenberg，S. westerstedeの11種類に分類された. 4. S. westerstedなど，広島県で今までにみられたことが無い新しい菌型が多数検出されたことから，当地方におけるサルモネラによる環境汚染の進みつつあることが推定できる. 5. このようなサルモネラによる環境汚染の実態から，今後の食品衛生上に及ぼす影響などについて指摘した.One hundred and ten water samples collected from the rivers, sewages and slaughterhouse in Fukuyama city in the eastern district of Hiroshima prefecture were examined for Salmonella organisms，from October 1967 to December 1968. It was found that 23.6% (13/55) of the rivers, 22.2% (8/36) of the sewages, and 36.8% (7/19) of the sewages of the slaughterhouse were contaminated by this organism. These results show that the percentage of contamination is smaller in Fukuyama city than that in a large cities，such as Tokyo or Osaka. Thirty three strains of Salmonella isolated from water samples were divided into the following 11 serotypes: S. derby，S. typhimurium，S. montevideo，S. thompson，S. mikawashima，S. narashino，S. enteritidis，S. meleagridis，S. give，S. senftenberg and S. westerstede. It might be presumed that the environmental contamination of the area by the organisms is increasing gradually，since new types of Salmonella，e.g. S. westerstede etc. never found in Hiroshima prefecture before，were isolated in the area

Roles of Macrophages in Advanced Liver Fibrosis, Identified Using a Newly Established Mouse Model of Diet-Induced Non-Alcoholic Steatohepatitis

Macrophages play critical roles in the pathogenesis of non-alcoholic steatohepatitis (NASH). However, it is unclear which macrophage subsets are critically involved in the development of inflammation and fibrosis in NASH. In TSNO mice fed a high-fat/cholesterol/cholate-based diet, which exhibit advanced liver fibrosis that mimics human NASH, we found that Kupffer cells (KCs) were less abundant and recruited macrophages were more abundant, forming hepatic crown-like structures (hCLS) in the liver. The recruited macrophages comprised two subsets: CD11c+/Ly6C−and CD11c− /Ly6C+ cells. CD11c+ cells were present in a mesh-like pattern around the lipid droplets, constituting the hCLS. In addition, CD11c+ cells colocalized with collagen fibers, suggesting that this subset of recruited macrophages might promote advanced liver fibrosis. In contrast, Ly6C+cells were present in doughnut-like inflammatory lesions, with a lipid droplet in the center. Finally, RNA sequence analysis indicates that CD11c+/Ly6C− cells promote liver fibrosis and hepatic stellate cell (HSC) activation, whereas CD11c−/Ly6C+ cells are a macrophage subset that play an anti-inflammatory role and promote tissue repair in NASH. Taken together, our data revealed changes in liver macrophage subsets during the development of NASH and shed light on the roles of the recruited macrophages in the pathogenesis of advanced fibrosis in NASH