Monday, August 26, 2013

Camels linked to mystery disease

Livestock may be a “reservoir” of germs that can infect people




A mysterious and deadly virus has sickened 94 people — killing 46 — in parts of the Middle East, Europe and northern Africa. A new study finds that camels (the one-humped type) may have introduced the new disease to people.
The germ responsible is a virus that lives in people’s lungs, throats and noses. Scientists recently named the disease it causes Middle East respiratory syndrome, or MERS.
Scientists discovered it after a few people became sick with severe pneumonia. This condition inflames and damages lungs. After examining the germ’s DNA, researchers discovered that the virus is related to some that infect bats. But no one with the disease had any known contact with bats.
Now researchers find that 50 retired racing camels from the Middle East nation of Oman carry antibodies against the MERS virus in their blood. Antibodies are proteins made by the immune system. They help identify or destroy foreign substances in the blood. They also serve as a marker of which particular foreign substance their host had encountered.
Finding antibodies in the blood of dromedary camels suggests the animals had been exposed to MERS. (Dromedary camels are the one-humped type common in North Africa and the Middle East.) An international team of researchers described their findings August 9 in the medical journal Lancet Infectious Diseases.
The researchers also found low levels of antibodies against the MERS virus in the blood of dromedary camels from the Canary Islands, off of Africa’s northwest coast.
None of the exposed camels appeared sick. And neither Oman nor the Canary Islands has reported human cases of MERS. But unconfirmed reports suggest some people with MERS in other countries may have been around camels or goats before falling ill.
The results could mean that camels and camel relatives, such as goats, may be a link in a chain of infection that can sicken people. It might also be that a virus similar to MERS has been in camels for a long time but only recently gained the ability to infect people.
Camels are a common livestock species in the Middle East and North Africa, where they are used for racing. They also are a source of meat and milk. So there are many ways people might contact infected animals, the researchers note.