ブラジルにおけるSARS-CoV-2の進化と流行
Darlan S Candido1,2, Ingra M Claro2,3, Jaqueline G de Jesus2,3
1Department of Zoology, University of Oxford, Oxford, UK.
Science (New York, N.Y.)
|July 25, 2020
まとめ
非医薬品介入 (NPI) は,ブラジルにおける重症急性呼吸器症候群コロナウイルス2 (SARS-CoV-2) の感染を減少させましたが,介入は依然として不十分です. ウイルスは,国際的導入と国内旅行を通じて広く広がり,流行の制御における継続的な課題を強調しています.
科学分野:
- 流行病学について
- ゲノミクス
- 数学的モデリング
背景:
- ブラジルでは,重症急性呼吸器症候群コロナウイルス2 (SARS-CoV-2) の流行が急速に拡大しています.
- 限られたデータは,SARS-CoV-2の拡散に対する非医薬品介入 (NPI) の有効性の評価を複雑にする.
- ウイルスの伝染の動態と進化の軌道を理解することは,ブラジルの公衆衛生対策にとって極めて重要です.
研究 の 目的:
- ブラジルにおけるSARS-CoV-2感染に対するNPIの影響を評価する.
- ブラジル国内でのSARS-CoV-2系統の起源と拡散を調査する.
- 流行を抑制するための現在の介入の十分さを評価する.
主な方法:
- 複製数に対するNPIの影響を推定するために,移動性駆動型伝達モデルを使用した.
- 427の新しいSARS-CoV-2ゲノムを配列化し,地理的に代表的なゲノムデータセットを分析した.
- ウイルスの導入,クラード分布,空間的な拡散パターンを分析した.
主要な成果:
- NPIはサンパウロとリオデジャネイロで生殖数 (R0) を3から1.6に減少させた.
- 国際的なSARS-CoV-2の導入は100件以上で,ブラジル株の76%はヨーロッパの3つのクラードから発生しました.
- 初期の拡散は局所的であったが,後の都市部からの輸出は国内旅行で増加した.
結論:
- NPIは,SARS-CoV-2の感染率を低減する上で測定可能な影響を示した.
- ブラジルの流行を助長したのは 複数の国際入口と その後の国内感染です
- 現行の介入は,国内でSARS-CoV-2の感染を効果的に制御するには不十分である.
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