感染症の出現における進化の役割
Rustom Antia1, Roland R Regoes, Jacob C Koella
1Department of Biology, Emory University, Atlanta, Georgia 30322, USA. rantia@emory.edu
Nature
|December 12, 2003
まとめ
新型感染症は,HIVのような病原体が進化して,人々の間で簡単に拡散するときに発生します. 生態学的変化は,このリスクを高め,疫病の可能性を高めることができます. この研究は,伝播のわずかな増加でさえも,発生確率を大幅に高める方法を示しています.
科学分野:
- *動物性感染症の発生
- * 病原体の進化について
- * 流行病学について
背景:
- *HIV,モンキーポックス,SARSなどの新型感染症は,動物の貯水池から予測不能に発生する.
- *生態学的変化は,病原体の動物から人間への伝播を容易にする可能性があります.
- *病原体の伝播ダイナミクスを理解することは,疫病の予測と予防に不可欠です.
研究 の 目的:
- *生態学的変化,病原体の進化,新型感染症の出現との関係を調査する.
- * 基本的生殖数 (R(0) の増加が病気の発生確率にどのように影響するか分析する.
- *二次感染の増加が流行の可能性に与える影響を定量化するため.
主な方法:
- * 病原体伝播ダイナミクスの理論モデリング.
- * 伝染性の向上に向けた病原体の進化に影響を与える要因の分析.
- * 感受性の高い集団における病気の拡散のシミュレーション.
主要な成果:
- *生態学的変化は,病原体のヒトへの侵入と持続的な伝播の機会を増やす可能性があります.
- * R ((0) のサブ流行性増加でさえ,二次感染の数を大幅に上昇させます.
- * 病原体がR(0) > 1に進化する確率は著しく増加し,病気の発生を促進します.
結論:
- *ヒトからヒトへの感染の拡大に向けた病原体の進化は,新型感染症の発生の主要な要因である.
- *生態学的破壊は,動物性感染症の拡散と疫病の蔓延に有利な条件を創造する上で重要な役割を果たします.
- * 伝染の可能性の増大は,流行の値以下であっても,将来のアウトブレイクのリスクを大幅に高めます.
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