Paradigm Shift Intervention Monitoring
twitter
Commentary
MERS Jeddah Camel and Case Sequence Match
Recombinomics Commentary
22:00
November 11, 2013
The above translation describes the PCR confirmation of MERS in a camel in a barn owned by the recent case (43M) from Jeddah (see map). PCR confirmation of MERS involves testing using primers representing two disnct regions of human MERS-CoV. This approach has led to the generation of full sequences which are >99.5% identical to the consensus sequence. This high level of identity is distinctly different from most of the closely related bat beta 2c sequences, which are, 92.5% identical. The only except was a bat sequence from Bisha which was an exact match with one of the human sequences (EMC/12) isolated from the first confirmed case, who lived in Bisha but was confirmed and died in Jeddah. This identity was for a short segment (203 BP). The size was limited due to the disruption of the cold chain during shipment of the sample from the Kingdom of Saudi Arabia (KSA) to Columbia University in New York.
However, since the above camel and case are alive a full sequence (over 30,000 BP) from each host is expected, and the detection by PCR strongly suggests the two sequences will be virtually identical (based on the specificity of the PCR test as well as temporal and geographic parameters associated with the two hosts.
The identity between these two samples will increase the confidence in the antibody results obtained from racing camels in Oman and camels in Egypt which were imported from Sudan for slaughter. The antibody testing showed that the antibodies recognized MERS-CoV, but not SARS-CoV or OC43. This specificity could have been due to other beta 2c virus similar to those found in bats in Asia, Europe, and Africa. However, the likely match between the two collections in Jeddah suggests that the camel antibodies are due to a MERS-CoV infection.
The presence of MERS in camels in Oman, Sudan, and Egypt as well as symptomatic camels linked to cases in the UAE and Batin indicates that MERS-CoV is present throughout the Middle East and the number of unreported cases in countries such as Sudan and Egypt is high (neither country has reported a human case).
The PCR match in Jeddah will also lead to more aggressive antibody and PCR testing in camels throughout the Middle East, which will help determine the geographic range and concentration of the virus, which is likely to be widespread and common.
These high levels will create considerable concern.
Recombinomics
Presentations
Recombinomics
Publications
Recombinomics
Paper
at Nature Precedings