【文献Abstract】新型コロナウイルスに対する布マスクの効果

〈要点〉

・2019年のCOVID-19パンデミックにより、特にプライマリケア環境において、医療用マスクを含む個人用保護具が不足した。この研究の目的は、医療臨床医の間で、呼吸器ウイルス感染を予防するための布製マスクの使用に関する現在のエビデンスを要約した。
・2020年　5つのデータベース、米国疾病予防管理センターのWebサイト、および特定された記事の参照リストを検索。
・検索により136のオリジナルの出版物が特定。 9件の研究が選択基準を満たし、これらの研究からデータの定性的統合を実行（4件の非ランダム化試験、3件の臨床検査、1件の単一症例実験、1件のRCT）。
・結果：布材料は医療用マスクよりも生物学的材料をブロックする効果が低く、布製マスクが医療用マスクよりもはるかに多くウイルス感染に関連していた。

〈雑感〉

・過去にもいろいろとマスクの効果について文献がでていたが、今回Ann Fam Medにも文献が乗っていたのでちょっと読んでみた。
・やはり不織布マスクの方が布製マスクよりも効果が高いという結果。
・もし不織布マスクがまたなくなって洗濯し再利用することになった場合のことを考えると、洗濯再利用したら効果がどう変化していくのかが気になるところ。

〈文献〉

Ann Fam Med. Jan-Feb 2021;19(1):55-62. doi: 10.1370/afm.2640.
The Potential for Cloth Masks to Protect Health Care Clinicians From SARS-CoV-2: A Rapid Review
Ariel Kiyomi Daoud , Jessica Kole Hall , Haylie Petrick , Anne Strong , Cleveland Piggott
Abstract
Purpose: The coronavirus disease 2019 (COVID-19) pandemic has led at times to a scarcity of personal protective equipment, including medical masks, for health care clinicians, especially in primary care settings. The objective of this review was to summarize current evidence regarding the use of cloth masks to prevent respiratory viral infections, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), among health care clinicians.

Methods: We searched 5 databases, the Centers for Disease Control and Prevention website, and the reference lists of identified articles on April 3, 2020. All identified publications were independently screened by 2 reviewers. Two authors independently extracted data and graded the studies. Randomized control trials (RCTs) were graded using the Consolidated Standards of Reporting Trials (CONSORT) checklist, and observational and nonhuman subject studies were graded using 11 domains common across frequently used critical appraisal tools. All discrepancies were resolved by consensus.

Results: Our search identified 136 original publications. Nine studies met inclusion criteria. We performed a qualitative synthesis of the data from these studies. Four nonrandomized trials, 3 laboratory studies, 1 single-case experiment, and 1 RCT were identified. The laboratory studies found that cloth materials provided measurable levels of particle filtration but were less efficacious at blocking biologic material than medical masks. The RCT found that cloth masks were associated with significantly more viral infections than medical masks.

Conclusions: The current literature suggests that cloth materials are somewhat efficacious in filtering particulate matter and aerosols but provide a worse fit and inferior protection compared to medical masks in clinical environments. The quality and quantity of literature addressing this question are lacking. Cloth masks lack evidence for adequate protection of health care clinicians against respiratory viral infections.