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1.
JMIR Public Health Surveill ; 6(3): e22853, 2020 Aug 10.
Article in English | MEDLINE | ID: covidwho-706264

ABSTRACT

[This corrects the article DOI: 10.2196/19170.].

2.
Aerosol Air Qual. Res. ; 6(20): 1167-1171, 2020.
Article in English | ELSEVIER | ID: covidwho-601949

ABSTRACT

The progression of COVID-19 worldwide can be tracked by identifying mutations within the genomic sequence of SARS-CoV-2 that occur as a function of time. Such efforts currently rely on sequencing the genome of SARS-CoV-2 in patient specimens (direct sequencing) or of virus isolated from patient specimens in cell cultures. A pilot SARS-CoV-2 air sampling study conducted at a clinic within a university student health care center detected the virus vRNA, with an estimated concentration of 0.87 virus genomes L –1air. To determine whether the virus detected was viable (‘live’), attempts were made to isolate the virus in cell cultures. Virus-induced cytopathic effects (CPE) were observed within two days post-inoculation of Vero E6 cells with collection media from air samples; however, rtRT-PCR tests for SARS-CoV-2 vRNA from cell culture were negative. Instead, three other fast-growing human respiratory viruses were isolated and subsequently identified, illustrating the challenge in isolating SARS-CoV-2 when multiple viruses are present in a test sample. The complete SAR-CoV-2 genomic sequence was nevertheless determined by Sanger sequencing and most closely resembles SARS-CoV-2 genomes previously described in Georgia, USA. Results of this study illustrate the feasibility of tracking progression of the COVID-19 pandemic using environmental aerosol samples instead of human specimens. Collection of a positive sample from a distance more than 2 m away from the nearest patient traffic implies the virus was in an aerosol.

3.
JMIR Public Health Surveill ; 6(2): e19170, 2020 06 01.
Article in English | MEDLINE | ID: covidwho-456505

ABSTRACT

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been growing exponentially, affecting over 4 million people and causing enormous distress to economies and societies worldwide. A plethora of analyses based on viral sequences has already been published both in scientific journals and through non-peer-reviewed channels to investigate the genetic heterogeneity and spatiotemporal dissemination of SARS-CoV-2. However, a systematic investigation of phylogenetic information and sampling bias in the available data is lacking. Although the number of available genome sequences of SARS-CoV-2 is growing daily and the sequences show increasing phylogenetic information, country-specific data still present severe limitations and should be interpreted with caution. OBJECTIVE: The objective of this study was to determine the quality of the currently available SARS-CoV-2 full genome data in terms of sampling bias as well as phylogenetic and temporal signals to inform and guide the scientific community. METHODS: We used maximum likelihood-based methods to assess the presence of sufficient information for robust phylogenetic and phylogeographic studies in several SARS-CoV-2 sequence alignments assembled from GISAID (Global Initiative on Sharing All Influenza Data) data released between March and April 2020. RESULTS: Although the number of high-quality full genomes is growing daily, and sequence data released in April 2020 contain sufficient phylogenetic information to allow reliable inference of phylogenetic relationships, country-specific SARS-CoV-2 data sets still present severe limitations. CONCLUSIONS: At the present time, studies assessing within-country spread or transmission clusters should be considered preliminary or hypothesis-generating at best. Hence, current reports should be interpreted with caution, and concerted efforts should continue to increase the number and quality of sequences required for robust tracing of the epidemic.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/epidemiology , Genome , Pneumonia, Viral/epidemiology , Data Analysis , Humans , Pandemics
5.
Pathog Glob Health ; 114(2): 64-67, 2020 03.
Article in English | MEDLINE | ID: covidwho-795

ABSTRACT

The global spread of the 2019-nCoV is continuing and is fast moving, as indicated by the WHO raising the risk assessment to high. In this article, we provide a preliminary phylodynamic and phylogeographic analysis of this new virus. A Maximum Clade Credibility tree has been built using the 29 available whole genome sequences of 2019-nCoV and two whole genome sequences that are highly similar sequences from Bat SARS-like Coronavirus available in GeneBank. We are able to clarify the mechanism of transmission among the countries which have provided the 2019-nCoV sequence isolates from their patients. The Bayesian phylogeographic reconstruction shows that the 2019-2020 nCoV most probably originated from the Bat SARS-like Coronavirus circulating in the Rhinolophus bat family. In agreement with epidemiological observations, the most likely geographic origin of the new outbreak was the city of Wuhan, China, where 2019-nCoV time of the most recent common ancestor emerged, according to molecular clock analysis, around November 25th, 2019. These results, together with previously recorded epidemics, suggest a recurring pattern of periodical epizootic outbreaks due to Betacoronavirus. Moreover, our study describes the same population genetic dynamic underlying the SARS 2003 epidemic, and suggests the urgent need for the development of effective molecular surveillance strategies of Betacoronavirus among animals and Rhinolophus of the bat family.


Subject(s)
Betacoronavirus/genetics , Chiroptera/virology , Coronavirus Infections/genetics , Coronavirus/genetics , Evolution, Molecular , Genome, Viral , Phylogeny , Pneumonia, Viral/genetics , Animals , Bayes Theorem , China/epidemiology , Coronavirus/isolation & purification , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , DNA, Viral/genetics , Disease Outbreaks , Disease Reservoirs/virology , Global Health , Humans , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Sequence Analysis, Protein , Zoonoses/epidemiology , Zoonoses/genetics
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