Detection of the Middle East Respiratory Syndrome Coronavirus Genome in an Air Sample Originating from a Camel Barn Owned by an Infected Patient

Azhar, Esam I.; Hashem, Anwar M.; El-Kafrawy, Sherif A.; Sohrab, Sayed Sartaj; Aburizaiza, Asad S.; Farraj, Suha A.; Hassan, Ahmed M.; Al-Saeed, Muneera S.; Jamjoom, Ghazi A.; Madani, Tariq A.

Recently, several MERS-CoV isolates were obtained from nasal samples from dromedary camels in Saudi Arabia, and their consensus genome sequences were found to be similar to published human MERS-CoV sequences, supporting the role of dromedary camels in human MERS-CoV infections (19) . In another report, we also provided evidence for the direct cross-species transmission of MERS-CoV from infected camels to their owner (20) . Serological data suggested that the virus was circulating in the herd before infecting the patient. Additionally, we showed based on reverse transcription-PCR (RT-PCR), viral isolation, and fullgenome sequencing that both MERS-CoV-Jeddah-human-1 (accession number KF958702) and MERS-CoV-Jeddah-camel-1 (accession number KF917527) isolates were 100% identical and contain characteristic mutations compared to other reported sequences, suggesting direct cross-species transmission from the camels to the patient. Here, we tried to extend our previous study and to examine whether air could play a role in MERS-CoV transmission. To this end, three air samples were collected from the camels' barn on three consecutive days as shown in Fig. 1 . All samples were screened by real-time RT-PCR targeting the upstream region of the E gene (UpE region) of MERS-CoV. Interestingly, only the air sample collected on 7 November 2013, the same day that one of the nine camels in the same barn tested positive for MERS-CoV ( Fig. 1) , tested positive for the UpE region. The two other air samples were negative for UpE by RT-PCR. Two other confirmatory real-time RT-PCR assays targeting the open reading frame 1a (ORF1a) and ORF1b regions confirmed the UpE-positive result of the first air sample, as shown in Table 1 .