High proportion of MERS-CoV shedding dromedaries at slaughterhouse with a potential epidemiological link to human cases, Qatar 2014

Farag, Elmoubasher A. B. A.; Reusken, Chantal B. E. M.; Haagmans, Bart L.; Mohran, Khaled A.; Raj, V. Stalin; Pas, Suzan D.; Voermans, Jolanda; Smits, Saskia L.; Godeke, Gert-Jan; Al-Hajri, Mohd. M.; Alhajri, Farhoud H.; Al-Romaihi, Hamad E.; Ghobashy, Hazem; El-Maghraby, Mamdouh M.; El-Sayed, Ahmed M.; Al Thani, Mohamed H. J.; Al-Marri, Salih; Koopmans, Marion P. G.

Swabs and lymph nodes were tested for MERS-CoV RNA by internally controlled RT-PCR targeting UpE and N genes, as described (3, 6) . The first camel isolate of MERS-CoV as described by Raj et al. (7) was obtained from the first group of 53 samples and among others sequences generated from this group have been used to define a general MERS-CoV typing fragment (8) . In total, 59% of the camels showed evidence for virus shedding in at least one type of swab at the time of slaughter ( Table 1 ). The percentage positive samples was the highest for nasal samples, followed by oral swabs, fecal swabs, and bron-chial swabs. All but one animals with virus shedding from any sample had a positive nasal swab. For saliva (oral), the percentage of positive samples was the highest for animals between 7 and 12 months of age. Lymph nodes from 53 animals were tested, yielding five positives. Approximation of the viral loads in the samples using the Ct values obtained with the UpE target showed no significant differences between types of samples and age groups (Fig. 1 ) It should be noted that viral loads with DCt !20 were observed only in the nasal swabs and the nasal swab sample with the highest viral load was found to contain infectious virus (7).