MERS-CoV: a global challenge.

In her closing remarks at the World Health Assembly in Geneva last week, WHO's Director-General Margaret Chan announced that the new Middle East Respiratory Syndrome coronavirus (MERS-CoV) was her present “greatest concern”.

What do we know about MERS-CoV? The novel virus was first reported in September, 2012, in a patient in Saudi Arabia. As of June 2, WHO has been informed of 53 laboratory-confirmed cases of infection, including 30 deaths. Most cases have arisen in the Middle East (Saudi Arabia, Qatar, Jordan, and the United Arab Emirates), with a smaller number of cases present elsewhere (Tunisia, Germany, UK, France, and Italy)—either related to travellers returning from the region or transferred to the country for care. Common symptoms in patients are acute, serious respiratory illness with fever, cough, shortness of breath, and breathing difficulties. Many of those infected develop severe pneumonia.

There have been small clusters of infection in several countries suggesting that person-to-person transmission is possible when close contact occurs. But there is no evidence of sustained transmission. Last week, a Lancet Article showed that the virus's incubation could be longer than previously reported—9–12 days instead of 1–9 days—which has implications for length of quarantine needed to prevent secondary cases.

Many unanswered questions remain about MERS-CoV, including the source of, and main risk factors for, infection. A collaborative global research effort will help close the gaps in knowledge. In this regard, news that the scientists at Erasmus Medical Centre, Netherlands, who first identified the virus, have applied for a patent on virus data has caused consternation. The researchers have publicly responded to say that they have sent the virus free of charge to many public research and health institutions and they will continue to do so. They have told media that they applied for a patent to ensure companies invest in making diagnostics, vaccines, and antiviral medication. Let us hope their expectations prove correct.

Free information sharing, trust, and research cooperation will be crucial to aid prevention, diagnosis, and treatment of this evolving global health threat.