RESUMEN
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.
Asunto(s)
Infecciones por Coronavirus/epidemiología , Coronavirus del Síndrome Respiratorio de Oriente Medio/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Análisis por Conglomerados , Femenino , Humanos , Masculino , Persona de Mediana Edad , Coronavirus del Síndrome Respiratorio de Oriente Medio/clasificación , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Epidemiología Molecular , Filogenia , Arabia Saudita/epidemiología , Análisis de Secuencia de ADN , Homología de Secuencia , Glicoproteína de la Espiga del Coronavirus/genética , Adulto JovenAsunto(s)
Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/transmisión , Exposición a Riesgos Ambientales , Coronavirus del Síndrome Respiratorio de Oriente Medio , Estaciones del Año , Animales , Camelus/virología , Infecciones por Coronavirus/historia , Infecciones por Coronavirus/virología , Genoma Viral , Historia del Siglo XXI , Humanos , Coronavirus del Síndrome Respiratorio de Oriente Medio/clasificación , Coronavirus del Síndrome Respiratorio de Oriente Medio/genética , Coronavirus del Síndrome Respiratorio de Oriente Medio/aislamiento & purificación , Filogenia , Vigilancia de la Población , Arabia Saudita/epidemiología , Secuenciación Completa del GenomaRESUMEN
During July-August 2015, the number of cases of Middle East respiratory syndrome (MERS) reported from Saudi Arabia increased dramatically. We reviewed the 143 confirmed cases from this period and classified each based upon likely transmission source. We found that the surge in cases resulted predominantly (90%) from secondary transmission largely attributable to an outbreak at a single healthcare facility in Riyadh. Genome sequencing of MERS coronavirus from 6 cases demonstrated continued circulation of the recently described recombinant virus. A single unique frameshift deletion in open reading frame 5 was detected in the viral sequence from 1 case.