SARS-CoV-2の暗号的感染と第1波のCOVID-19
Jessica T Davis1, Matteo Chinazzi1, Nicola Perra1,2
1Laboratory for the Modeling of Biological and Socio-technical Systems, Northeastern University, Boston, MA, USA.
Nature
|October 25, 2021
まとめ
2020年1月までに,早期の重症急性呼吸器症候群コロナウイルス2 (SARS-CoV-2) のコミュニティ感染がヨーロッパと米国で発生した可能性が高い.国際旅行は,監視システムによる検出が限られているSARS-CoV-2の導入を促した.
科学分野:
- 流行病学
- 数学的モデリング
- 公衆衛生
背景:
- 深刻な急性呼吸器症候群コロナウイルス2 (SARS-CoV-2) の導入と世界的に局所的な感染の初期タイムラインについては不確実性があります.
- 2020年初めの限られた検査と多孔性移動スクリーニングは,SARS-CoV-2の無制限の感染を促進した可能性がある.
研究 の 目的:
- 世界的にSARS-CoV-2感染の早期拡散を理解する.
- ヨーロッパとアメリカにおけるSARS-CoV-2の導入と局所感染の開始の時間帯を決定する.
- 監視システムによるSARS-CoV-2感染の検出率を推定する.
主な方法:
- SARS-CoV-2の拡散をシミュレートするために,世界的なメタポピュレーション流行モデルを使用した.
- ウイルスの導入の原動力として国際旅行パターンを分析した.
- 異なる地域における累積感染率の推定.
主要な成果:
- 2020年1月までに,SARS-CoV-2のコミュニティ感染はヨーロッパと米国に存在していた可能性が高い.
- 国際旅行は2019年12月から2020年1月の間に発生する可能性のあるSARS-CoV-2の導入の主な要因として特定されました.
- 2020年3月上旬までに,SARS-CoV-2感染のわずか1〜4%が監視によって検出されました.
- 2020年7月までに米国では0.78%から15.2%,欧州では0.19%から13.2%の異質な感染発症率が観察されました.
結論:
- モデルの結果は,SARS-CoV-2が発見されるよりずっと早くヨーロッパと米国に密かに導入され,伝播されたことを示唆しています.
- 発見は,ウイルスの拡散における国際旅行の重要性を強調し,早期の監視の限界を強調しています.
- この研究は,将来の疫病に対する検査と対応戦略を強化するために,モデル主導の監視システムを開発するための洞察を提供します.
関連する概念動画
02:33Retroviruses
12.9K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
12.9K
00:57Viral Recombination
24.0K
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.
24.0K
02:28Leaky Scanning
5.3K
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R...
5.3K
01:20Infection
9.1K
When a pathogen enters the body and reproduces, it can cause an infection, damage body cells, and cause illness symptoms that eventually lead to disease. Therefore, its prevention requires breaking the chain of infection.
The chain begins with pathogens: bacteria, viruses, fungi, prions, or parasites such as protozoa helminths. These can be present on the skin as transient or resident flora, or they can be acquired from the environment. Identifying and treating the type of infection and...
The chain begins with pathogens: bacteria, viruses, fungi, prions, or parasites such as protozoa helminths. These can be present on the skin as transient or resident flora, or they can be acquired from the environment. Identifying and treating the type of infection and...
9.1K
00:36Viral Mutations
34.9K
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
34.9K
01:29Viruses with RNA Genomes
229
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
229