Journal Article > ResearchAbstract
Nat Genet. 19 January 2015; Volume 47 (Issue 3); DOI:10.1038/ng.3195
Merker M, Blin C, Mona S, Duforet-Frebourg N, Lecher S, et al.
Nat Genet. 19 January 2015; Volume 47 (Issue 3); DOI:10.1038/ng.3195
Mycobacterium tuberculosis strains of the Beijing lineage are globally distributed and are associated with the massive spread of multidrug-resistant (MDR) tuberculosis in Eurasia. Here we reconstructed the biogeographical structure and evolutionary history of this lineage by genetic analysis of 4,987 isolates from 99 countries and whole-genome sequencing of 110 representative isolates. We show that this lineage initially originated in the Far East, from where it radiated worldwide in several waves. We detected successive increases in population size for this pathogen over the last 200 years, practically coinciding with the Industrial Revolution, the First World War and HIV epidemics. Two MDR clones of this lineage started to spread throughout central Asia and Russia concomitantly with the collapse of the public health system in the former Soviet Union. Mutations identified in genes putatively under positive selection and associated with virulence might have favored the expansion of the most successful branches of the lineage.
Journal Article > ResearchFull Text
Emerg Infect Dis. 1 February 2016; Volume 22 (Issue 2); 217-23.; DOI:10.3201/eid2202.151250
Crowe SJ, Maenner MJ, Kuah S, Erickson BR, Coffee M, et al.
Emerg Infect Dis. 1 February 2016; Volume 22 (Issue 2); 217-23.; DOI:10.3201/eid2202.151250
To determine whether 2 readily available indicators predicted survival among patients with Ebola virus disease in Sierra Leone, we evaluated information for 216 of the 227 patients in Bo District during a 4-month period. The indicators were time from symptom onset to healthcare facility admission and quantitative real-time reverse transcription PCR cycle threshold (Ct), a surrogate for viral load, in first Ebola virus-positive blood sample tested. Of these patients, 151 were alive when detected and had reported healthcare facility admission dates and Ct values available. Time from symptom onset to healthcare facility admission was not associated with survival, but viral load in the first Ebola virus-positive blood sample was inversely associated with survival: 52 (87%) of 60 patients with a Ct of >24 survived and 20 (22%) of 91 with a Ct of <24 survived. Ct values may be useful for clinicians making treatment decisions or managing patient or family expectations.