Middle East respiratory syndrome coronavirus (MERS-CoV) infection
Middle East respiratory syndrome coronavirus (MERS-CoV) infection is an uncommon coronavirus infection (<1000 cases) with the first case reported in Saudi Arabia in 2012. It most commonly causes pneumonia and acute renal failure with a mortality rate of ~40%. MERS-CoV raises concern because of its similarity to SARS-CoV infection, with similar spread via infected cases who travel by air.
MERS-CoV primary cases have been isolated to the Middle East (most commonly Saudi Arabia), travel-related cases have been reported in western Europe, North America and eastern Asia 3,5. The average age is ~50 years with a slight male predominance of 1.5:1 3.
The infection may be subclinical. If symptomatic, features range from mild upper respiratory tract coryzal symptoms (high fever, cough) to severe respiratory distress and multiorgan failure 3,4. Vomiting and diarrhea are also a feature 3.
MERS-CoV belongs to lineage C of the β-coronaviruses, the first known to infect humans, and is a single-stranded RNA virus 4. The origin and mode of transmission are unclear, but bats are the likely original source and transmission suspected to be via dromedary camels 3-5,9. Human-to-human transmission occurs and is responsible for the international spread 4,5.
MERS-CoV infection can result in:
The radiographic features of MERS-CoV infection can be variable due to the variability in the severity of disease 7.
Reported chest x-ray features in a case series of 55 patients 8:
- peripheral ground-glass opacity (65%)
- consolidation (20%)
- pneumothoraces, pleural effusions, and progressive involvement of all lungs zones are associated with higher mortality
Reported CT chest features in a case series of seven patients 6:
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- 2. Coleman CM, Frieman MB. Emergence of the Middle East respiratory syndrome coronavirus. PLoS Pathog. 2013;9 (9): e1003595. doi:10.1371/journal.ppat.1003595 - Free text at pubmed - Pubmed citation
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- 4. Zhang N, Jiang S, Du L. Current advancements and potential strategies in the development of MERS-CoV vaccines. Expert Rev Vaccines. 2014;13 (6): 761-74. doi:10.1586/14760584.2014.912134 - Free text at pubmed - Pubmed citation
- 5. Durai P, Batool M, Shah M et-al. Middle East respiratory syndrome coronavirus: transmission, virology and therapeutic targeting to aid in outbreak control. Exp. Mol. Med. 2015;47 (8): e181. doi:10.1038/emm.2015.76 - Free text at pubmed - Pubmed citation
- 6. Ajlan AM, Ahyad RA, Jamjoom LG et-al. Middle East respiratory syndrome coronavirus (MERS-CoV) infection: chest CT findings. AJR Am J Roentgenol. 2014;203 (4): 782-7. doi:10.2214/AJR.14.13021 - Pubmed citation
- 7. Wiwanitkit V. Chest CT findings in MERS. AJR Am J Roentgenol. 2015;204 (1): W111. doi:10.2214/AJR.14.13301 - Pubmed citation
- 8. Das KM, Lee EY, Jawder SE et-al. Acute Middle East Respiratory Syndrome Coronavirus: Temporal Lung Changes Observed on the Chest Radiographs of 55 Patients. AJR Am J Roentgenol. 2015;205 (3): W267-S274. doi:10.2214/AJR.15.14445 - Pubmed citation
- 9. Ng LFP, Hiscox JA. Coronaviruses in animals and humans. (2020) BMJ (Clinical research ed.). 368: m634. doi:10.1136/bmj.m634 - Pubmed