Epidemiology of a Novel Recombinant Middle East Respiratory Syndrome Coronavirus in Humans in Saudi Arabia.
Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory illness in humans. Fundamental questions about circulating viruses and transmission routes remain.



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.



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.



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.
Ministry of Health.
Abdullah M
AM
Assiri
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, Georgia.
Claire M
CM
Midgley
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Glen R
GR
Abedi
Ministry of Health Department of Family and Community Medicine, King Saud Medical City.
Abdulaziz
A
Bin Saeed
Ministry of Health.
Malak M
MM
Almasri
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Xiaoyan
X
Lu
Ministry of Health.
Hail M
HM
Al-Abdely
Ministry of Health.
Osman
O
Abdalla
Ministry of Health.
Mutaz
M
Mohammed
Ministry of Health.
Homoud S
HS
Algarni
Ministry of Health.
Raafat F
RF
Alhakeem
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Senthilkumar K
SK
Sakthivel
Ministry of Health Field Epidemiology Training Program, Ministry of Health, Riyadh, Kingdom of Saudi Arabia.
Randa
R
Nooh
Ministry of Health Field Epidemiology Training Program, Ministry of Health, Riyadh, Kingdom of Saudi Arabia.
Zainab
Z
Alshayab
Ministry of Health Field Epidemiology Training Program, Ministry of Health, Riyadh, Kingdom of Saudi Arabia.
Mohammad
M
Alessa
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Ganesh
G
Srinivasamoorthy
Ministry of Health.
Saeed Yahya
SY
AlQahtani
Ministry of Health.
Ali
A
Kheyami
Ministry of Health.
Waleed Husein
WH
HajOmar
Ministry of Health.
Talib M
TM
Banaser
Ministry of Health.
Ahmad
A
Esmaeel
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Aron J
AJ
Hall
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Aaron T
AT
Curns
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Azaibi
A
Tamin
Ministry of Health.
Ali Abraheem
AA
Alsharef
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Dean
D
Erdman
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
John T
JT
Watson
Division of Viral Diseases, National Center for Immunization and Respiratory Diseases.
Susan I
SI
Gerber
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016000:Cluster Analysis; D018352:Coronavirus Infections / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D065207:Middle East Respiratory Syndrome Coronavirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D017720:Molecular Epidemiology; D010802:Phylogeny; D012529:Saudi Arabia / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D064370:Spike Glycoprotein, Coronavirus / Q000235:genetics; D055815:Young Adult
D064370:Spike Glycoprotein, Coronavirus
MERS; MERS epidemiology; MERS phylogeny; MERS transmission; Middle East respiratory syndrome; Saudi Arabia; coronavirus; recombinant