Middle East respiratory syndrome coronavirus-a 10-year (2012-2022) global analysis of human and camel infections, genomic sequences, lineages, and geographical origins

Int J Infect Dis. 2023 Jun:131:87-94. doi: 10.1016/j.ijid.2023.03.046. Epub 2023 Mar 29.


Objectives: The World Health Organization priority zoonotic pathogen Middle East respiratory syndrome (MERS) coronavirus (CoV) has a high case fatality rate in humans and circulates in camels worldwide.

Methods: We performed a global analysis of human and camel MERS-CoV infections, epidemiology, genomic sequences, clades, lineages, and geographical origins for the period January 1, 2012 to August 3, 2022. MERS-CoV Surface gene sequences (4061 bp) were extracted from GenBank, and a phylogenetic maximum likelihood tree was constructed.

Results: As of August 2022, 2591 human MERS cases from 26 countries were reported to the World Health Organization (Saudi Arabia, 2184 cases, including 813 deaths [case fatality rate: 37.2%]) Although declining in numbers, MERS cases continue to be reported from the Middle East. A total of 728 MERS-CoV genomes were identified (the largest numbers were from Saudi Arabia [222: human = 146, camels = 76] and the United Arab Emirates [176: human = 21, camels = 155]). A total of 501 'S'-gene sequences were used for phylogenetic tree construction (camels [n = 264], humans [n = 226], bats [n = 8], other [n=3]). Three MERS-CoV clades were identified: clade B, which is the largest, followed by clade A and clade C. Of the 462 clade B lineages, lineage 5 was predominant (n = 177).

Conclusion: MERS-CoV remains a threat to global health security. MERS-CoV variants continue circulating in humans and camels. The recombination rates indicate co-infections with different MERS-CoV lineages. Proactive surveillance of MERS-CoV infections and variants of concern in camels and humans worldwide, and development of a MERS vaccine, are essential for epidemic preparedness.

Keywords: Genetic diversity; MERS; MERS-CoV; Phylogenetic analysis; S-gene; Zoonotic reservoir.

MeSH terms

  • Animals
  • Camelus
  • Coronavirus Infections* / epidemiology
  • Coronavirus Infections* / veterinary
  • Genomics
  • Humans
  • Middle East / epidemiology
  • Middle East Respiratory Syndrome Coronavirus* / genetics
  • Phylogeny
  • Saudi Arabia / epidemiology