Scientists have found signs of Middle East respiratory syndrome (MERS), the new coronavirus that has so far killed about half of the people infected by it, in one-humped camels.
The findings, published in the journal The Lancet Infectious Diseases, show that blood samples taken from 50 dromedary camels from Oman contain antibodies to MERS, suggesting they have either encountered the virus (or a similar one) before, or they are the reservoir (or at least one of the reservoirs) for MERS.
"As new human cases of MERS-CoV continue to emerge, without any clues about the sources of infection except for people who caught it from other patients, these new results suggest that dromedary camels may be one reservoir of the virus that is causing MERS-CoV in humans," the researchers said in a statement. "Dromedary camels are a popular animal species in the Middle East, where they are used for racing, and also for meat and milk, so there are different types of contact of humans with these animals that could lead to transmission of a virus."
Previously, MERS has been linked with bats, but the researchers noted that this isn't likely how most humans are becoming infected with the virus since humans and bats aren't often in close contact.
The study, which was led by Dr. Chantal Reusken of the National Institute for Public Health and the Environment in the Netherlands, involved 349 blood serum samples that were taken from a number of livestock animals from different countries around the world, including Spain, Chile, Oman and the Netherlands. Science NOW reported that the researchers also wanted blood serum samples from Saudi Arabia and Qatar, since these countries are where most cases of MERS have occurred, but the countries would not cooperate with the study.
Researchers analyzed the blood samples for antibodies against MERS, antibodies against SARS (which is a coronavirus, just as MERS is), and the HCoV-OC43 strain of coronavirus. They did not find any MERS antibodies in the 160 blood samples from the sheep, goats and cattle in Spain and the Netherlands, but did find the antibodies in the 50 samples from the camels from Oman. Interestingly, researchers also found low levels of the antibodies in 14 percent of camels from the Canary Islands, where there had previously been no evidence of MERS circulating.
They found that only the dromedary camels had the MERS antibodies; other kinds of camels or camel-related creatures, like the alpaca, llama and Bactrian camel (the two-humped camel), did not show evidence of MERS.
However, Science NOW talked with one of the study authors, Marion Koopmans, about why we shouldn't get our hopes too high yet:
The researchers didn't try to isolate the actual virus from the samples, so they can't be 100 percent sure the camels were infected with MERS. They had only blood serum available, which is not a good starting material, Koopmans says, and besides, once an animal has high levels of antibodies, "you don't expect much luck in finding the virus."
Fortunately, MERS doesn't seem to be spreading that easily. Reuters earlier reported that even though the death rate is high -- it's sickened a little more than 90 people since it was first identified last year, and has killed about half of them -- it does not seem easily contractible, especially compared with SARS.
Last month, the Food and Drug Administration issued emergency authorization for the development of a MERS diagnostic test.