The discovery, described in the journal 'Emerging Infectious Diseases', points to a likely animal origin for the disease but an intermediary animal is likely also involved, researchers from the Columbia University, EcoHealth Alliance, and the Ministry of Health of Saudi Arabia said, Xinhua reported.
The researchers collected more than 1,000 samples from seven bat species in regions where cases of MERS were identified in Bisha, Unaizah, and Riyadh between October 2012 and April 2013.
One fecal sample from an Egyptian tomb Bat, or taphozous perforatus, collected within a few kilometres of the first known MERS victim's home contained sequences of a virus identical to those recovered from the victim, they said.
"There have been several reports of finding MERS-like viruses in animals. None were a genetic match," W. Ian Lipkin, director of the Centre for Infection at the Columbia University and co-author of the study, said in a statement.
"In this case we have a virus in an animal that is identical in sequence to the virus found in the first human case. Importantly, it's coming from the vicinity of that first case," Lipkin said.
MERS was first described in September 2012 and continues to spread. Close to 100 cases have been reported worldwide, 70 of them from Saudi Arabia. Though the causative agent, a new type of coronavirus, has been determine, the origin of the virus is still not known.
The researchers said bats are known to the reservoirs of viruses that can cause human disease including rabies and Severe Acute Respiratory Syndrome (SARS).
In some instances, the infection may spread directly from bats to humans through inadvertent inhalation of infected aerosols, ingestion of contaminated food, or, less commonly, a bite wound. In other instances, bats can first infect intermediate hosts. The researchers said that the indirect method for transmission is more likely in MERS.
"There is no evidence of direct exposure to bats in the majority of human cases of MERS," says Ziad Memish, Saudi Arabia's deputy minister of health and lead author of the study.
"Given that human-to-human transmission is inefficient, we speculate that an as-yet-to-be determined intermediate host plays a critical role in human disease."
In the coming days, the researchers plan to report the results of their investigation into the possible presence of MERS in camels, sheep, goats, and cattle.
Earlier this month, European scientists found traces of antibodies against the MERS virus in dromedary, or one-humped camels, but not the virus itself. This suggests the camels were at one point infected with MERS or a similar virus.
--IANS (Posted on 23-08-2013)