RESUMEN
This investigation shows that MERS-CoV ELISA antibodies remain in dromedary camels at least for 9 years, most probably lifelong. The viral infection was most likely acquired at a young age when maternal antibodies have receded between 4 to 8 month of age. Additionally, in the investigated herd, the 4 ELISA antibody negative dromedary camels remained negative also for 9 years, indicating, that no MERS-CoV was circulating in the herd. Until today, the specific source of MERS-CoV infection for young dromedaries remains unknown.
RESUMEN
Middle East respiratory syndrome coronavirus (MERS-CoV) infection in humans has a high mortality of >30%. Dromedaries are the reservoir of MERS-CoV and the main source of human infections. However, MERS-CoV infections in dromedaries are usually subclinical. Rapid diagnosis of MERS-CoV infection in these animals is important in preventing camel-to-human transmission of the virus. The possible cross-reactivity of a previously reported rapid nucleocapsid protein-based antigen detection assay for MERS-CoV was examined with different CoVs, including Tylonycteris bat CoV HKU4, dromedary camel CoV UAE-HKU23, human CoV-229E, human CoV-OC43, severe acute respiratory syndrome CoV-2 and rabbit CoV HKU14, where none of them showed false-positive results. The assay was further validated using quantitative real-time reverse transcription-polymerase chain reaction-confirmed MERS-CoV-positive and MERS-CoV-negative dromedary nasal samples collected in Dubai, the United Arab Emirates, which showed that the rapid antigen detection assay has a specificity of 100% and sensitivity of 91.7%.
RESUMEN
MERS-CoV was isolated from nasal swabs for 10 days from an adult female camel which displayed clear nasal discharge from both nostrils. When MERS-CoV ELISA antibodies appeared in the camel's blood, the virus was no longer present in its nasal cavities.