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Wednesday, June 25, 2014

11 Week Sustained MERS Transmission - Jeddah To Tehran


Recombinomics Commentary 07:15
June 25, 2014
Tehran University of Medical Sciences has released partial N gene sequences from three recent MERS cases which appear to match the three cases described in WHO updates (June 11 and 13).  Two are sisters (50F and 52F) from Kerman (May 17 collections 82772-Kerman and 82769-Kerman) which exactly match each other and the sequence from the Jeddah export to Orlando, Florida (Florida/USA-2_Saudi Arabia_2014) via commercial airline with connections in London, Boston, and Atlanta. 

This sequence is closely related to a Jeddah export to Greece, as well as earlier sequences from cases in Jeddah and Mecca (
six cases in Jeddah and Mecca (C7149 and C7770 from hospital A collected on April 3 and 7, respectively, as well as C7569 from hospital B collected on April 5, followed by Jeddah sequences C8826 and C9055 collected on April 12 and April 14 from hospital A and C, respectively, as well as Mecca (C9355) collected on April 15).

The third sequence from Iran (80946-Tehran) was collected a month after (June 17 and the prompt release of this important sequence by researchers in Tehran is to be commended) the Kerman samples, and is likely from the health care worker (35F) linked to Kerman sisters (described in the WHO June 13 update).  This sequence matched the Kerman/Orlando sequences, but had one additional polymorphism, C29329T which encoded T225I in the N gene.  All of the Jeddah sub-clade sequences had ORF 8b non-synonymous polymorphisms, L40P and K60N, confirming sustained transmission from April 3 in Jeddah to June 17 in Tehran.

This sustained transmission was suggested in the WHO announcement associated with the 6th PHEIC (Public Health Emergency of International Concerns), which noted that there was no evidence for sustained MERS transmission in communities.  The addition of the “community” qualifier indirectly acknowledged sustained transmission in health care settings.  This sustained transmission was indirectly acknowledged in WHO explanations for the spike in MERS cases, which was attributed to infection control issues.

However, the exported case to Greece, as well as the three cases in Iran, which were directly or indirectly linked to a symptomatic pilgrim who returned to Iran after performing Umrah in the Kingdom of Saudi Arabia (KSA) support sustained transmission outside of hospital settings, WHO qualifiers and proclamations notwithstanding.