著者

氏家 無限 加藤 康幸 黒木 淳 寺島 俊和 伊藤 稔之 麻岡 大裕 白野 倫徳 柿木 康孝

出版者

一般社団法人 日本感染症学会

雑誌

感染症学雑誌 (ISSN:03875911)

巻号頁・発行日

vol.95, no.1, pp.32-36, 2021-01-20 (Released:2021-08-01)

参考文献数

10

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The novel coronavirus disease 2019 (COVID-19) was first reported to the World Health Organization by the WHO country office in China in December 2019 and has since become a worldwide pandemic. In Japan, COVID-19 is a designated infectious disease under the Infectious Disease Control Act, meaning that hospitalization or isolation measures are required for infected persons. It has been noted that in some cases, patients show positive PCR test results even after discharge from the hospital upon meeting the discharge criteria for COVID-19. However, so far, there is a lack of substantial evidence on the pathogenesis of reinfection or relapse in patients with COVID-19. We report 4 cases of COVID-19 who showed repeat-positive PCR test results for SARS-COV-2 after discharge from the hospital, and assessed their infectivity using clinical information collected via a public epidemiological survey. All 4 cases showed a repeat-positive PCR test results within 40 days of the initial onset of symptoms. All the PCR test results showed high Ct values of 33 or higher in the repeat-positive test. In addition, neutralizing antibodies were detected in all cases within 3 days from the date of the repeat-positive test. Furthermore, an epidemiological survey was conducted in 18 persons who were in close contact with the 4 cases, and 11 of them tested negative by the PCR test, and no case of secondary infection was found. Based on these findings, the risk of secondary infection from the 4 cases was considered as low. No specimens collected at the time of the first infection or virus culture test results were available for further evaluation. Issues remain to be resolved in respect of the systems needed for cooperation with healthcare providers and the laboratory testing required for the evaluation of re-infection. In order to further elucidate the pathogenesis of COVID-19, and to provide appropriate medical care, it is essential to evaluate the infectivity of patients with a repeat-positive PCR test and to accumulate further knowledge about the disease.

著者

中川 裕太 笠松 悠 福岡 里紗 森田 諒 山根 和彦 小西 啓司 麻岡 大裕 中河 秀憲 白野 倫徳 天羽 清子 外川 正生 後藤 哲志

出版者

一般社団法人 日本感染症学会

雑誌

感染症学雑誌 (ISSN:03875911)

巻号頁・発行日

vol.94, no.6, pp.814-820, 2020-11-20 (Released:2021-06-10)

参考文献数

11

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大阪市立総合医療センターに入院したCOVID-19関連肺炎13例において,再検例を含むのべ20件の胸部CT画像について検討した.全例で胸膜直下の病変とground-glass opacity(GGO)を認めたが,胸水,心嚢水,縦隔・肺門部リンパ節腫脹,空洞形成は認めなかった.また,酸素投与を要した3例は下葉のvolume loss とともに胸膜直下の病変と結合する気管支血管束の病変が認められた.発症時期から画像所見を分類するとGGOは発症早期(10日未満)に多く認められ,crazy-paving pattern,consolidation,背側のconsolidation の帯状の融合像は発症後期(10日以降)に多く認められた.鑑別疾患としてはインフルエンザなどによるウイルス性肺炎と器質化肺炎が重要と考えられた.詳細な問診による発症からの期間と胸部CT画像の特徴的な所見や経時的変化を合わせて理解することで,COVID-19の事前確率を適切に評価し,診断と治療および感染対策につなげることが重要である.