Epidemiology of a Novel Recombinant Middle East Respiratory Syndrome Coronavirus in Humans in Saudi Arabia

J Infect Dis. 2016 Sep 1;214(5):712-21. doi: 10.1093/infdis/jiw236. Epub 2016 Jun 14.

Abstract

Background: Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory illness in humans. Fundamental questions about circulating viruses and transmission routes remain.

Methods: We assessed routinely collected epidemiologic data for MERS-CoV cases reported in Saudi Arabia during 1 January-30 June 2015 and conducted a more detailed investigation of cases reported during February 2015. Available respiratory specimens were obtained for sequencing.

Results: During the study period, 216 MERS-CoV cases were reported. Full genome (n = 17) or spike gene sequences (n = 82) were obtained from 99 individuals. Most sequences (72 of 99 [73%]) formed a discrete, novel recombinant subclade (NRC-2015), which was detected in 6 regions and became predominant by June 2015. No clinical differences were noted between clades. Among 87 cases reported during February 2015, 13 had no recognized risks for secondary acquisition; 12 of these 13 also denied camel contact. Most viruses (8 of 9) from these 13 individuals belonged to NRC-2015.

Discussions: Our findings document the spread and eventual predominance of NRC-2015 in humans in Saudi Arabia during the first half of 2015. Our identification of cases without recognized risk factors but with similar virus sequences indicates the need for better understanding of risk factors for MERS-CoV transmission.

Keywords: MERS; MERS epidemiology; MERS phylogeny; MERS transmission; Middle East respiratory syndrome; Saudi Arabia; coronavirus; recombinant.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cluster Analysis
  • Coronavirus Infections / epidemiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Middle East Respiratory Syndrome Coronavirus / classification
  • Middle East Respiratory Syndrome Coronavirus / genetics
  • Middle East Respiratory Syndrome Coronavirus / isolation & purification*
  • Molecular Epidemiology
  • Phylogeny
  • Saudi Arabia / epidemiology
  • Sequence Analysis, DNA
  • Sequence Homology
  • Spike Glycoprotein, Coronavirus / genetics
  • Young Adult

Substances

  • Spike Glycoprotein, Coronavirus