Coronaviruses evolve quickly and have a long history of shifting between animal species, leading scientists to explore where MERS-CoV comes from and how people become infected. Thus far, evidence suggests bats may be a reservoir of the virus and that camels may have a role as an intermediate host of MERS-CoV. In humans, epidemiological studies show that the virus can be transmitted from person to person but only between people in close contact with one another, such as family members or patients being treated in clinical settings. Recent outbreaks have been closely linked to hospital settings.
Scientists supported by NIAID Centers of Excellence for Influenza Research and Surveillance are working to develop a point-of-care test for MERS-CoV. CEIRS researchers also developed a laboratory test to detect antibodies to a key MERS-CoV protein based on a form of HIV that cannot cause illness. They used this assay to test for MERS antibodies in dromedary camels, water buffalo, pigs, cows, sheep, and goats in Egypt. More than 90 percent of camels tested positive for these antibodies, while all of the other animals tested negative, suggesting that MERS-CoV or a related virus had infected dromedary camels. NIAID scientists also are exploring the possibility of foodborne transmission of MERS-CoV, which is the potential for humans to become infected by eating meat or drinking unpasteurized milk contaminated with the virus.