MERS

中东呼吸综合征

Evidence-backed information EN 3/7 applicable sections · ZH 3/7 applicable sections Updated Oct 23, 2026

Middle East respiratory syndrome (MERS) is a viral respiratory disease caused by Middle East respiratory syndrome-related coronavirus (MERS-CoV), first identified in Saudi Arabia in June 2012 ^[1]. It belongs to the coronavirus family alongside SARS-CoV and SARS-CoV-2, which have collectively caused severe respiratory disease outbreaks in the 21st century ^[2]. Compared with seasonal human coronaviruses that typically cause mild illness, MERS-CoV carries a significant mortality rate, though its global spread remains limited ^[3]^[1]. The virus is believed to have originated in bats, with dromedary camels serving as a key intermediate reservoir linked to human infection ^[4]^[2]^[1].

Read the full clinical and epidemiological profile 4

Syndrome or outcome definition

MERS is defined as a viral respiratory infection caused by Middle East respiratory syndrome-related coronavirus (MERS-CoV), a member of the coronavirus family that emerged in the 21st century alongside SARS-CoV and SARS-CoV-2 ^[3]^[2]^[1]. Genetic evidence indicates that MERS-CoV likely originated in bats, and genetically diverse coronaviruses related to MERS-CoV have been identified in bat populations worldwide ^[2]. The virus is sustained in dromedary camel populations, where a dominant MERS-CoV lineage was discovered in Saudi Arabia and has been linked to subsequent human outbreaks ^[4].

Clinical criteria and consequences

Clinical manifestations of MERS range from asymptomatic infection to severe disease, with severity depending on age and underlying health status ^[1]. Typical symptoms include fever, cough, diarrhea, and shortness of breath, and the disease tends to be more severe in individuals with pre-existing health problems ^[1]. Among the seven known human coronaviruses, MERS-CoV is grouped with SARS-CoV and SARS-CoV-2 as emerging pathogens associated with significant mortality, in contrast to seasonal coronaviruses that generally produce mild-to-moderate illness ^[3].

Occurrence and burden

The first identified case of MERS occurred in June 2012 in Jeddah, Saudi Arabia, and the majority of cases have since been reported from the Arabian Peninsula ^[1]. As of January 2021, over 2,600 cases had been reported globally, including 45 cases during 2020, with approximately 35% of diagnosed patients dying from the disease ^[1]. Notable outbreaks beyond the Arabian Peninsula occurred in South Korea in 2015—where 184 confirmed cases and 19 deaths were reported by late June 2015—and additional cases appeared in South Korea in 2018 linked to travel from Kuwait ^[1]. A 2014 hospital-related outbreak in Saudi Arabia added hundreds of cases, and a 2018 outbreak in the same country contributed to the cumulative burden ^[1]. Dromedary camels in Saudi Arabia were found to harbor a dominant MERS-CoV lineage responsible for Middle Eastern and South Korean outbreaks ^[4].

References

1 Wikipedia contributors. MERS - Wikipedia [Internet]. Wikipedia. cited 3 Sept 2026. Available from: https://en.wikipedia.org/wiki/MERS
2 Cui J et al. Origin and evolution of pathogenic coronaviruses. Nat Rev Microbiol. 2019 Mar. PMID: 30531947. doi: 10.1038/s41579-018-0118-9. PubMed: https://pubmed.ncbi.nlm.nih.gov/30531947/
3 Kesheh MM et al. An overview on the seven pathogenic human coronaviruses. Rev Med Virol. 2022 Mar. PMID: 34339073. doi: 10.1002/rmv.2282. PubMed: https://pubmed.ncbi.nlm.nih.gov/34339073/
4 Su S et al. Epidemiology, Genetic Recombination, and Pathogenesis of Coronaviruses. Trends Microbiol. 2016 Jun. PMID: 27012512. doi: 10.1016/j.tim.2016.03.003. PubMed: https://pubmed.ncbi.nlm.nih.gov/27012512/