Deadly MERS Virus Traced to Egyptian Tomb Bat
First reported in Saudi Arabia in September 2012, MERS continues to spread causing kidney failure and severe acute pneumonia in the nearly 100 cases reported across the globe.
Now a team of investigators from the Center for Infection and Immunity (CII) at Columbia University’s Mailman School of Public Health, EcoHealth Alliance, and the Ministry of Health of the Kingdom of Saudi Arabia, who were searching for an animal reservoir, have discovered a 100% genetic match of the virus in a bat found near the first known human case.
The discovery points to the likely animal origin for the disease, although researchers say that an intermediary animal is likely also involved.
There have been several reports of finding MERS-like viruses in animals. None were a genetic match. 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. W. Ian Lipkin, MD, director of the Center for Infection and Immunity
Over a six-week period during field expeditions in October 2012 and April 2013, 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. Extensive analysis, performed using polymerase chain reaction and DNA sequencing, revealed the presence of a wide range of alpha and beta coronaviruses in up to a third of bat samples. One fecal sample from an Egyptian Tomb Bat (Taphozous perforatus) collected within a few kilometers of the first known MERS victim’s home contained sequences of a virus identical to those recovered from the victim.
Bats are the reservoirs of viruses that can cause human disease including rabies, Hendra, Nipah, Marburg, and 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 suggest 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. 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. Ziad Memish, MD, Deputy Minister of Health, Kingdom of Saudi Arabia
We are continuing to look for evidence of the virus in wildlife and domestic animals, and investigating the mechanisms by which the virus causes human disease. W. Ian Lipkin, MD, director of the Center for Infection and Immunity
In the coming days, the researchers will be reporting the results of its investigation into the possible presence of MERS in other animals, including camels, sheep, goats, and cattle.