Mers virus originated in S African bats?

Published Tuesday, July 30, 2013

By Majorie van Leijen

Scientists are one step closer to understanding the Mers Coronavirus (Mers-CoV).

A coronavirus identified in South African bats has shown far-reaching similarities with the Mers-CoV, which has been identified in humans.

Scientists from the University of Bonn in Germany and researchers in South Africa came up with these findings, which were published in the journal Emerging Infectious Diseases.

The similarity is closest to the Mers-CoV identified thus far, and the findings might provide insight into the origins of Mers-CoV, the deadly virus which has baffled doctors and scientists with no conclusive understanding about its origins so far.

According to the findings, Mers-CoV has a close genetic relationship with the South African bat derived Coronavirus termed PML/2011. A relationship between Mers-CoV and the Coronavirus found in European bats was concluded earlier, but no genetic relationship has thus far been stronger than the one found with the South African bat-derived virus.

The likeness is similar to that between Mers-CoV and Sars, the virus that caused a pandemic in 2002.

The findings enable speculations of an African origin for bat reservoir hosts of Mers-CoV ancestors, pointed out the scientists. This hypothesis is likely considering that migration of viruses from Africa to Saudi Arabia has been seen before, such as with the exportation of Rift Valley fever virus from East Africa, which led to a severe outbreak in Saudi Arabia in 2000.

However, the hypothesis is challenged by limitations of the research, such as the small sampling size. The researchers tested 62 South African bats from 13 species for coronaviruses, and the closely-related PML/2011 virus was found in one female bat.

The renowned medical journal Lancet points out that bats are probably not the immediate contact for human cases because human contact with bats is generally infrequent. However, it is possible that the virus crossed from bats to an agricultural animal, which then spread widely within the Arabian Peninsula, suggested the journal.

Mers-CoV was first identified 15 months ago and there have been 91 cases with 46 deaths globally. The latest fatality was reported on Saturday in Saudi Arabia, where most cases have been reported.