Cross-sectional surveillance of Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels and other mammals in Egypt, August 2015 to January 2016

Abstract

A cross-sectional study was conducted in Egypt to determine the prevalence of Middle East respiratory syndrome coronavirus (MERS-CoV) in imported and resident camels and bats, as well as to assess possible transmission of the virus to domestic ruminants and equines. A total of 1,031 sera, 1,078 nasal swabs, 13 rectal swabs, and 38 milk samples were collected from 1,078 camels in different types of sites. In addition, 145 domestic animals and 109 bats were sampled. Overall, of 1,031 serologically-tested camels, 871 (84.5%) had MERS-CoV neutralising antibodies. Seroprevalence was significantly higher in imported (614/692; 88.7%) than resident camels (257/339; 5.8%) (p < 0.05). Camels from Sudan (543/594; 91.4%) had a higher seroprevalence than those from East Africa (71/98; 72.4%) (p < 0.05). Sampling site and age were also associated with MERS-CoV seroprevalence (p < 0.05). All tested samples from domestic animals and bats were negative for MERS-CoV antibodies except one sheep sample which showed a 1:640 titre. Of 1,078 camels, 41 (3.8%) were positive for MERS-CoV genetic material. Sequences obtained were not found to cluster with clade A or B MERS-CoV sequences and were genetically diverse. The presence of neutralising antibodies in one sheep apparently in contact with seropositive camels calls for further studies on domestic animals in contact with camels.

A systematic review of MERS-CoV seroprevalence and RNA prevalence in dromedary camels: Implications for animal vaccination

“…Higher in camels > 2yrs p < 0.0001 (Ali et al, 2017a) Ethiopia 1-≤2yrs 93% (n = 31) 2-13yrs 97% (n = 157) None Not significant (Reusken et al, 2014b) Iraq < 2yrs 89% (n = 44) > 2yrs 84% (n = 136) 2-4yrs 81% (n = 58) > 4yrs 86% (n = 78)…”

“…Samples taken from the large feral camel population in Australia were seronegative, along with dromedaries in Kazakhstan and in zoos in Japan, and North America (Reusken et al, 2013a;Alexandersen et al, 2014;Hemida et al, 2014b;Crameri et al, 2015;Shirato et al, 2015;Miguel et al, 2016). No other species tested alongside dromedaries had neutralising antibodies except a small number of alpacas and llamas living in close quarters with dromedaries in Israel (David et al, 2018), and 1 sheep in Egypt (Ali et al, 2017a). Seroprevalence was > 71% in all 4 studies conducted in dromedary populations epidemiologically linked with human MERS-CoV infection.…”

A rapid scoping review of Middle East respiratory syndrome coronavirus in animal hosts

“…Although the upper respiratory tract is now understood to be the primary site of viral replication and shedding, it is important to understand the role of other potential routes of transmission for understanding risk. Therefore, the negative results of observational studies (Al‐Muhairi et al, ; Azhar et al, ) are as important as the positive findings (Ali, El‐Shesheny, et al, ; Reusken et al, ) as they provide a more complete picture of possible routes of transmission.…”

MERS coronavirus outbreak: Implications for emerging viral infections

“…Recent studies, including those based on serological evidence, support the role of dromedary camels as important zoonotic sources of human MERS-CoV infection. MERS-CoV antibodies are present in more than 90% of dromedary camels tested in the Middle East and in many African countries (Ali et al, 2017a;Chu et al, 2015;Farag et al, 2015;Hemida et al, 2013Hemida et al, , 2014Hemida et al, , 2017aMüller et al, 2015;Reusken et al, 2014). Dromedary camel exposure within 2 weeks of illness onset has been identified as a significant risk factor in a study examining MERS-CoV infection cases documented between May and November 2014 in KSA (Alraddadi et al, 2016a).…”

“…There is growing evidence that dromedary camels act as the source of MERS-CoV. Dromedary camels' sera from different parts of the world -especially from the Middle East and broad areas of Africa, including Nigeria, Tunisia, Egypt and Ethiopiahave tested positive for anti-MERS-CoV antibodies (Ali et al, 2017b;Chu et al, 2015;Farag et al, 2015;Meyer et al, 2014b;Müller et al, 2015;Reusken et al, 2013aReusken et al, , 2014Saqib et al, 2017). Serological studies on camels in Africa and the Middle East within the last 30 years suggest that MERS-CoV was circulating among camels for decades before it was first documented in human beings in 2012 (Meyer et al, 2014b;Reusken et al, 2014).…”