Friday, March 04, 2016

EID Journal: MERS-CoV Infection, Replication & Transmission In Alpacas

Coronavirus - Credit CDC PHIL

# 11,096

Not quite three weeks ago, in EID Journal: MERS-CoV Antibodies In Alpacas - Qatar, we saw the first evidence that domesticated animals other than dromedary camels are susceptible to MERS-CoV infection.  

Alpacas are part of the same biological family (Camelidae) as dromedaries (as are Bactrian camels, llamas, vicuñas, and guanacos). 

Today we've two research papers appearing in the EID Journal where they challenged three Alpacas with the MERS virus, monitored its replication and transmission, and then rechallenged the test subjects a second time to test for immunity. 

The discovery that  Alpacas developed immunity after recovering from their initial infection is a hopeful sign that a MERS vaccine might be protective in dromedary camels. 

Given the logistical difficulties of using dromedary camels as laboratory test subjects, the researchers are also hopeful that Alpacas may be a suitable surrogate.  

Volume 22, Number 6—June 2016


Infection, Replication, and Transmission of Middle East Respiratory Syndrome Coronavirus in Alpacas

Danielle R. Adney, Helle Bielefeldt-Ohmann, Airn E. Hartwig, and Richard A. BowenComments to Author 
Middle East respiratory syndrome coronavirus is a recently emerged pathogen associated with severe human disease. Zoonotic spillover from camels appears to play a major role in transmission. Because of logistic difficulties in working with dromedaries in containment, a more manageable animal model would be desirable. 

We report shedding and transmission of this virus in experimentally infected alpacas (n = 3) or those infected by contact (n = 3). Infectious virus was detected in all infected animals and in 2 of 3 in-contact animals. All alpacas seroconverted and were rechallenged 70 days after the original infection. Experimentally infected animals were protected against reinfection, and those infected by contact were partially protected. 

Necropsy specimens from immunologically naive animals (n = 3) obtained on day 5 postinfection showed virus in the upper respiratory tract. These data demonstrate efficient virus replication and animal-to-animal transmission and indicate that alpacas might be useful surrogates for camels in laboratory studies.
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A second report from the EID Journal this week, reported similar results.

Volume 22, Number 6—June 2016


Experimental Infection and Response to Rechallenge of Alpacas with Middle East Respiratory Syndrome Coronavirus

Gary CrameriComments to Author , Peter A. Durr, Reuben Klein, Adam Foord, Meng Yu, Sarah Riddell, Jessica Haining, Dayna Johnson, Maged G. Hemida, Jennifer Barr, Malik Peiris, Deborah Middleton, and Lin-Fa Wang

We conducted a challenge/rechallenge trial in which 3 alpacas were infected with Middle East respiratory syndrome coronavirus. The alpacas shed virus at challenge but were refractory to further shedding at rechallenge on day 21. The trial indicates that alpacas may be suitable models for infection and shedding dynamics of this virus.

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