Further Studies on MERS-Coronavirus in imported and local breeds of camels in Egypt

Background: Middle East respiratory syndrome (MERS) is a last emerging viral disease of coronaviridae family which appear firstly in Middle East. MERS affect lower respiratory tract of human. There are many research emphasized that camels are carrier for MERS-CoV due to close contact of some infected cases with infected camels of Arabian Peninsula and proved by isolation and sequencing of MERS-CoV from these infected camels and detection of antibodies specific for MERS-CoV in the serum. Objective: This study act as a safe guard for prevalence of new Exotic diseases like MERS through the importation of camels from some endemic countries in Africa, and to check our local breeds of camels in different governorates of Egypt for presence of MERS-CoV among our local breeds. Methods: In the present study, During the period of March 2016 to December 2017, 1500 nasal swabs were collected from imported camels in Birqash veterinary quarantine, 195 nasal swab and Serum samples collected from imported breeds in abattoirs of different governorates in Egypt, In addition to 98 nasal swabs and serum samples were collected from local breeds presented in some camel farms. All nasal swabs tested using real time RT-PCR while serum samples were tested using indirect ELISA technique. Results: From 1500 nasal swabs of imported camel breeds collected in Birqash veterinary quarantine, ten samples (0.66%) were positive for MERS-CoV by real time RT-PCR. Out of 195 serum samples which collected from imported camels in abattoirs of some governorates, 110 samples (56.4%) were positive for the presence of specific antibodies against MERS-CoV while the nasal swabs of these tested animals of the abattoirs were negative for detection of MERS-CoV. All 98 nasal swabs and serum samples which collected from local breeds of camel's farms were negative for MERS-CoV or its specific antibodies. Phylogenetic analysis of coronavirus ORF1a partial sequences in some positive nasal swab samples of imported breeds (with accession number on gen bank; MH184776, MH184776 and MH184777) confirmed presence of different branch of MERS-CoV from which isolated in Middle East. Conclusion: MERS-CoV is amphixnoses in which both human and camels are source of infection and cause mild to severe respiratory disease in human while camels consider carrier of MERS-CoV.