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Multifacility Outbreak of Middle East Respiratory Syndrome in Taif, Saudi Arabia.

Assiri A, Abedi GR, Bin Saeed AA, Abdalla MA, al-Masry M, Choudhry AJ, Lu X, Erdman DD, Tatti K, Binder AM, Rudd J, Tokars J, Miao C, Alarbash H, Nooh R, Pallansch M, Gerber SI, Watson JT - Emerging Infect. Dis. (2016)

Bottom Line: Fifteen patients, including 4 HCP, were associated with 1 dialysis unit.Similar gene sequences among patients unlinked by time or location suggest unrecognized viral transmission.Circulation persisted in multiple healthcare settings over an extended period, underscoring the importance of strengthening MERS-CoV surveillance and infection-control practices.

View Article: PubMed Central - PubMed

ABSTRACT
Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) is a novel respiratory pathogen first reported in 2012. During September 2014-January 2015, an outbreak of 38 cases of MERS was reported from 4 healthcare facilities in Taif, Saudi Arabia; 21 of the 38 case-patients died. Clinical and public health records showed that 13 patients were healthcare personnel (HCP). Fifteen patients, including 4 HCP, were associated with 1 dialysis unit. Three additional HCP in this dialysis unit had serologic evidence of MERS-CoV infection. Viral RNA was amplified from acute-phase serum specimens of 15 patients, and full spike gene-coding sequencing was obtained from 10 patients who formed a discrete cluster; sequences from specimens of 9 patients were closely related. Similar gene sequences among patients unlinked by time or location suggest unrecognized viral transmission. Circulation persisted in multiple healthcare settings over an extended period, underscoring the importance of strengthening MERS-CoV surveillance and infection-control practices.

No MeSH data available.


Related in: MedlinePlus

Midpoint-rooted phylogenetic tree inferred from multiple-sequence alignment of 10 new cases of Middle East respiratory syndrome coronavirus (MERS-CoV) spike open reading frame sequences (4,062 nt) from Taif, Saudi Arabia (brackets). Colored circles identify healthcare facilities; numbers indicate individual patients. Taif sequences are shown in context with the closest related sequences that comprise the Hafr-Al-Batin_1 clade, as originally defined by Cotton et al. (17), and with sequences related to the 2015 outbreak event in South Korea. For clarity, the remaining published sequences are collapsed into triangles. Published sequences are designated by GenBank accession number, strain name, and month and year of sample collection. The estimated neighbor-joining tree was constructed from nucleotide alignments by using MEGA version 6.06 (http://www.megasoftware.net). Bootstrap support values (1,000 replicates) ≥70% are plotted at the indicated internal branch nodes. Scale bar shows the genetic distance as the number of nucleotide substitutions per site. KSA, Kingdom of Saudi Arabia.
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Figure 2: Midpoint-rooted phylogenetic tree inferred from multiple-sequence alignment of 10 new cases of Middle East respiratory syndrome coronavirus (MERS-CoV) spike open reading frame sequences (4,062 nt) from Taif, Saudi Arabia (brackets). Colored circles identify healthcare facilities; numbers indicate individual patients. Taif sequences are shown in context with the closest related sequences that comprise the Hafr-Al-Batin_1 clade, as originally defined by Cotton et al. (17), and with sequences related to the 2015 outbreak event in South Korea. For clarity, the remaining published sequences are collapsed into triangles. Published sequences are designated by GenBank accession number, strain name, and month and year of sample collection. The estimated neighbor-joining tree was constructed from nucleotide alignments by using MEGA version 6.06 (http://www.megasoftware.net). Bootstrap support values (1,000 replicates) ≥70% are plotted at the indicated internal branch nodes. Scale bar shows the genetic distance as the number of nucleotide substitutions per site. KSA, Kingdom of Saudi Arabia.

Mentions: Because of limited available serum volume and generally low virus loads, we focused sequencing efforts on the MERS-CoV spike gene, which has been shown to be a reliable proxy for virus genotyping (16) and encodes the receptor-binding domain responsible for attachment to host cells. Sequencing of the spike gene coding region was attempted on all rRT-PCR–positive specimens; complete sequences were obtained from serum samples of 10 patients. The mean N2 rRT-PCR Ct value of serum samples that were successfully sequenced was 32.8 (range 31.1–35.6), compared with 37.8 (range 35.6–40.6) for samples with failed sequencing. Phylogenetic analysis of the 10 Taif spike sequences showed that the viruses formed a single, discrete cluster located within the Hafr-Al-Batin clade (17) and were most closely related to MERS-CoV viruses circulating in Riyadh during 2013 and 2014 (Figure 2). Sequences from 6 patients (1 from hospital A, 4 from hospital B’s dialysis unit, and 1 from hospital D) were identical, and all 10 sequences possessed 2 defining base substitutions at positions 3,670 (G>A) and 3,840 (C>T) (Technical Appendix Table). Sequences from 2 epidemiologically linked cases (patients 27 and 30 in the Technical Appendix Table) associated with hospital D formed a subcluster among the Taif viruses on the basis of 2 defining base substitutions at positions 1,679 (C>T) and 3,496 (G>A).


Multifacility Outbreak of Middle East Respiratory Syndrome in Taif, Saudi Arabia.

Assiri A, Abedi GR, Bin Saeed AA, Abdalla MA, al-Masry M, Choudhry AJ, Lu X, Erdman DD, Tatti K, Binder AM, Rudd J, Tokars J, Miao C, Alarbash H, Nooh R, Pallansch M, Gerber SI, Watson JT - Emerging Infect. Dis. (2016)

Midpoint-rooted phylogenetic tree inferred from multiple-sequence alignment of 10 new cases of Middle East respiratory syndrome coronavirus (MERS-CoV) spike open reading frame sequences (4,062 nt) from Taif, Saudi Arabia (brackets). Colored circles identify healthcare facilities; numbers indicate individual patients. Taif sequences are shown in context with the closest related sequences that comprise the Hafr-Al-Batin_1 clade, as originally defined by Cotton et al. (17), and with sequences related to the 2015 outbreak event in South Korea. For clarity, the remaining published sequences are collapsed into triangles. Published sequences are designated by GenBank accession number, strain name, and month and year of sample collection. The estimated neighbor-joining tree was constructed from nucleotide alignments by using MEGA version 6.06 (http://www.megasoftware.net). Bootstrap support values (1,000 replicates) ≥70% are plotted at the indicated internal branch nodes. Scale bar shows the genetic distance as the number of nucleotide substitutions per site. KSA, Kingdom of Saudi Arabia.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4696715&req=5

Figure 2: Midpoint-rooted phylogenetic tree inferred from multiple-sequence alignment of 10 new cases of Middle East respiratory syndrome coronavirus (MERS-CoV) spike open reading frame sequences (4,062 nt) from Taif, Saudi Arabia (brackets). Colored circles identify healthcare facilities; numbers indicate individual patients. Taif sequences are shown in context with the closest related sequences that comprise the Hafr-Al-Batin_1 clade, as originally defined by Cotton et al. (17), and with sequences related to the 2015 outbreak event in South Korea. For clarity, the remaining published sequences are collapsed into triangles. Published sequences are designated by GenBank accession number, strain name, and month and year of sample collection. The estimated neighbor-joining tree was constructed from nucleotide alignments by using MEGA version 6.06 (http://www.megasoftware.net). Bootstrap support values (1,000 replicates) ≥70% are plotted at the indicated internal branch nodes. Scale bar shows the genetic distance as the number of nucleotide substitutions per site. KSA, Kingdom of Saudi Arabia.
Mentions: Because of limited available serum volume and generally low virus loads, we focused sequencing efforts on the MERS-CoV spike gene, which has been shown to be a reliable proxy for virus genotyping (16) and encodes the receptor-binding domain responsible for attachment to host cells. Sequencing of the spike gene coding region was attempted on all rRT-PCR–positive specimens; complete sequences were obtained from serum samples of 10 patients. The mean N2 rRT-PCR Ct value of serum samples that were successfully sequenced was 32.8 (range 31.1–35.6), compared with 37.8 (range 35.6–40.6) for samples with failed sequencing. Phylogenetic analysis of the 10 Taif spike sequences showed that the viruses formed a single, discrete cluster located within the Hafr-Al-Batin clade (17) and were most closely related to MERS-CoV viruses circulating in Riyadh during 2013 and 2014 (Figure 2). Sequences from 6 patients (1 from hospital A, 4 from hospital B’s dialysis unit, and 1 from hospital D) were identical, and all 10 sequences possessed 2 defining base substitutions at positions 3,670 (G>A) and 3,840 (C>T) (Technical Appendix Table). Sequences from 2 epidemiologically linked cases (patients 27 and 30 in the Technical Appendix Table) associated with hospital D formed a subcluster among the Taif viruses on the basis of 2 defining base substitutions at positions 1,679 (C>T) and 3,496 (G>A).

Bottom Line: Fifteen patients, including 4 HCP, were associated with 1 dialysis unit.Similar gene sequences among patients unlinked by time or location suggest unrecognized viral transmission.Circulation persisted in multiple healthcare settings over an extended period, underscoring the importance of strengthening MERS-CoV surveillance and infection-control practices.

View Article: PubMed Central - PubMed

ABSTRACT
Middle East respiratory syndrome (MERS) coronavirus (MERS-CoV) is a novel respiratory pathogen first reported in 2012. During September 2014-January 2015, an outbreak of 38 cases of MERS was reported from 4 healthcare facilities in Taif, Saudi Arabia; 21 of the 38 case-patients died. Clinical and public health records showed that 13 patients were healthcare personnel (HCP). Fifteen patients, including 4 HCP, were associated with 1 dialysis unit. Three additional HCP in this dialysis unit had serologic evidence of MERS-CoV infection. Viral RNA was amplified from acute-phase serum specimens of 15 patients, and full spike gene-coding sequencing was obtained from 10 patients who formed a discrete cluster; sequences from specimens of 9 patients were closely related. Similar gene sequences among patients unlinked by time or location suggest unrecognized viral transmission. Circulation persisted in multiple healthcare settings over an extended period, underscoring the importance of strengthening MERS-CoV surveillance and infection-control practices.

No MeSH data available.


Related in: MedlinePlus