Thursday, June 12, 2014

Eurosurveillance: MERS-CoV Antibodies & RNA In Camel’s Milk – Qatar

Photo: ©FAO/Ami Vitale

Credit FAO

 

 

# 8736

 

 

Today’s Eurosurveillance Journal is MERS-centric, with no less than four articles or features on this emerging coronavirus.   First, links to today’s studies, then a closer look at one focusing on MERS and camel’s milk.

 


Seroepidemiology of Middle East respiratory syndrome (MERS) coronavirus in Saudi Arabia (1993) and Australia (2014) and characterisation of assay specificity

by MG Hemida, RA Perera, RA Al Jassim, G Kayali, LY Siu, P Wang, KW Chu, S Perlman, MA Ali, A Alnaeem, Y Guan, LL Poon, L Saif, M Peiris

Middle East respiratory syndrome coronavirus (MERS-CoV) RNA and neutralising antibodies in milk collected according to local customs from dromedary camels, Qatar, April 2014

by CB Reusken, EA Farag, M Jonges, GJ Godeke, AM El-Sayed, SD Pas, VS Raj, KA Mohran, HA Moussa, H Ghobashy, F Alhajri, AK Ibrahim, BJ Bosch, SK Pasha, HE Al-Romaihi, M Al-Thani, SA Al-Marri, MM AlHajri, BL Haagmans, MP Koopmans

Research articles


Assessment of the Middle East respiratory syndrome coronavirus (MERS-CoV) epidemic in the Middle East and risk of international spread using a novel maximum likelihood analysis approach

by C Poletto, C Pelat, D Lévy-Bruhl, Y Yazdanpanah, PY Boëlle, V Colizza

News


The 2014 Hajj and Umrah – current recommendations

by Eurosurveillance editorial team

 

The study with perhaps the greatest immediate impact looks at a possible route of transmission of the virus from camels to humans.

 

Eurosurveillance, Volume 19, Issue 23, 12 June 2014

Rapid communications

Middle East respiratory syndrome coronavirus (MERS-CoV) RNA and neutralising antibodies in milk collected according to local customs from dromedary camels, Qatar, April 2014

C B Reusken1,2, E A Farag2,3, M Jonges2,4, G J Godeke4, A M El-Sayed3, S D Pas1, V S Raj1, K A Mohran5, H A Moussa6, H Ghobashy5, F Alhajri5, A K Ibrahim6,7, B J Bosch8, S K Pasha6, H E Al-Romaihi3, M Al-Thani3, S A Al-Marri3, M M AlHajri ()3, B L Haagmans1, M P Koopmans1,4


  • Antibodies to Middle East respiratory syndrome coronavirus (MERS-CoV) were detected in serum and milk collected according to local customs from 33 camels in Qatar, April 2014. At one location, evidence for active virus shedding in nasal secretions and/or faeces was observed for 7/12 camels; viral RNA was detected in milk of five of these seven camels. The presence of MERS-CoV RNA in milk of camels actively shedding the virus warrants measures to prevent putative food-borne transmission of MERS-CoV.

    In April 2014, serum, nasal swabs and rectal swabs were taken from 33 milking dromedary camels at two locations in Qatar (Al Shahaniya and Dukhan), areas with known Middle East respiratory syndrome coronavirus (MERS-CoV) circulation in camels [1] and data not shown. In addition, milk was collected from these animals according to local customs. Serum samples and milk were tested for the presence of MERS-CoV-specific antibodies by protein microarray, with confirmation by virus neutralisation.

    Swabs and milk were tested for the presence of MERS-CoV RNA by real-time reverse transcription (RT)-PCR testing for multiple genomic targets. Antibodies to MERS-CoV were detected in serum and milk from all camels at both locations. At the Dukhan location, none of the 21 animals tested was actively shedding viral RNA from the nose and/or in faeces and no evidence for the presence of MERS-CoV RNA in milk was observed. At the Al Shahaniya location, evidence for active virus shedding was observed for seven of the 12 camels tested. Viral RNA was detected in milk of five of the seven camels with active virus shedding.

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    While important findings, there are a few caveats due.


    First, the degree of RNA detection was pretty low – too low to allow for virus isolation.  And while viral RNA was detected in the some of the milk samples, the milk was collected `according to local customs’ – which means the camel’s udders were not cleaned prior to milking (and milking takes place immediately after calves have suckled), meaning the milk could have been contaminated from outside sources.

     

    Of course, whether the milk is contaminated during collection or while still in the udder, becomes somewhat moot if people are being infected from consuming it. At this point, however, it isn’t clear whether there were enough infectious virus particles in the raw milk to transmit the disease.

     

    The low level of virus detection could also have been influenced by the rigors (both time & environmentally related) of shipment of samples to labs outside of Qatar.  It is also possible that the existence of antibodies (detected in milk samples as well) could have affected the amount of virus detected in vitro.

     

    More research, particularly under better controlled conditions, is needed.  The authors conclude:

     

    Nevertheless, it can be concluded that the presence of MERS-CoV RNA in raw milk as consumed locally might represent a source for zoonotic transmission of MERS-CoV and prudence is called for. Munster et al. showed that heat treatment (30 minutes at 63 °C) of MERS-CoV-containing camel milk reduced levels of infectious virus below detection level [24]. Boiling milk before consumption could be an easy, achievable local measure to prevent transmission and to preserve consumption of camel milk.

     

    As always, I would urge my readers to follow the link and read this report in its entirety, as I’ve only hit a few of the highlights. For an earlier look at the potential for milk to carry, and potentially convey, the MERS virus, you may wish to revisit:

     

    EID Journal: Stability Of MERS-CoV In Milk