MERS Attacks: The story and evolution of the deadly Middle East virus
Published online 2 June 2014
The WHO has not declared MERS-CoV an epidemic yet, due to current low human-to-human transmission. But is there reason for concern?
The Middle East respiratory syndrome coronavirus (MERS-CoV), which first appeared in the Middle East, is now causing concern across the rest of the world. The Philippines, Malaysia, France, Germany and the US have all confirmed cases, and very recently Australia is reported to be anxious, saying that it is vulnerable to a disease like this too.
The virus’ transmission modes and its degree of adaptability remain largely mysterious, but its potential to kill is certain – with 193 deaths reported worldwide, the majority over a few months. This Nature Middle Eastexclusive infograph shows the extent of the viral contagion and reach, visually contrasting its high fatality record with those of H1N1 and SARS.
As of last week, according to the World Health Organization (WHO), around 636 lab-confirmed cases have been reported in 19 countries. Most of the infections are concentrated in the Kingdom of Saudi Arabia, where the virus was first discovered.
In this comprehensive look at the current global MERS picture, Nature Middle East speaks to the scientist who blew the whistle on its emergence in June 2012. Ali Mohamed Zaki, an Egyptian virologist, formerly employed at a hospital in Jeddah, identified the new virus after working on the case of a 60-year-old Saudi patient who died from an acute respiratory condition. Islam Hussein, a prominent MIT virologist, hears from Zaki the story of this “patient zero” and his fight to have the virus exposed and recounts it here.
When scientists first encountered MERS – a close cousin of the SARS virus – memories of the devastation caused by SARS generated immense pressure to find the source of the outbreak. Both viruses were first believed to have emerged from bats. Professor Ian Lipkin and his colleagues at Columbia University started testing bats in Saudi Arabia and recovered a small viral fragment identical to MERS-CoV.
But human-bat contact is minimal, so Lipkin and his colleagues began searching for another animal reservoir to which humans are more exposed and might have played a role in MERS-CoV zoonotic transmission. They managed to isolate a virus from nasal swabs collected from dromedary camels in Saudi Arabia whose whole-genome sequence was identical to human MERS CoV. The current working hypothesis is that MERS-CoV emerged from interspecies transmission from bats to camels, which then transmitted the virus to humans.
“However, there are many questions about its spread, including how the virus is transmitted from camels to humans. We still don’t know whether camels are the only animal reservoirs of this virus,” writes Hussein in an editorial considering the odds of science winning the war against MERS.
Professionals in the region have played down the likelihood of an imminent danger of a MERS epidemic even in countries, like Egypt, with a poor history of viral control. However the region is still vulnerable, mainly because of mass movement between Arab countries, specifically Saudi Arabia and the rest of the Arab and Muslim world.
The looming Hajj season, when many millions of Muslims travel to Saudi Arabia, has put the issue of containing the coronavirus at centre stage. Hussein offers insight into what measures have been effective in the past in curbing similar virus outbreaks.
By WHO’s standards MERS has not reached emergency levels on a global scale, but this status could change if precautions are not taken by high-risk countries like Saudi Arabia and if more research is not taken on.
Saudi Arabia’s government is talking with pharmaceutical companies about developing a vaccine. Nature Middle East writer, Moheb Costandi, writes here about a compound that potently inhibits the replication of human coronaviruses, including SARS and MERS, and could lead to antiviral drugs that would contain them. Already, a group of researchers have designed a peptide which would hinder the spread of MERS, but there aren’t any anti-MERS drugs on the market so far.
Making a vaccine a viable priority for pharmaceutical companies to produce it en masse remains a challenge. As Costandi points out in his story, it’s a long and expensive process. In Boston, another group of scientists have identified antibodies that could help neutralize the virus, but again, it’s unlikely that these antibodies will find their way to market in the near future.
The coming months will reveal whether MERS has as high a human and economic cost as H1N1 or SARS. Its effects will depend on many factors; ecological outcomes, crisis management efforts, research success, and the virus’s potential to mutate and transmit efficiently between humans.