Blog | Tuesday, July 30, 2013

New SARS-like virus: how big is the threat?


Reports of a new SARS-like virus have been trickling out of the Arabian Peninsula. SARS, you may recall, was a frighteningly severe viral illness that emerged in southeast China in 2003, spreading rapidly from human to human. Health care workers caring for SARS patients were especially at risk, with the doctor who discovered the illness dying of it a short time later.

SARS is caused by a virus known as SARS-CoV, a coronavirus that probably originated in palm civets, a raccoon-like animal native to Southeast Asia. Coronaviruses are common in humans, usually causing colds or "stomach flu." This particular coronavirus spread rapidly between people, causing the "severe acute respiratory syndrome" that gave the disease its name. Mortality, which was remarkably high, increased with the age of the victim, but even in younger, healthier people was quite deadly.

Ten years later no pandemic has emerged, perhaps due to a vigorous public health response, but probably also due to the biology of the virus. Like many similar viruses, its spread was facilitated by crowded living conditions and by the ease of international travel. Its demise is less well understood.

Since the early part of 2013, a new, similar illness has emerged in the Arabian Peninsula. Now called "MERS-Cov" (Middle East Respiratory Syndrome Coronavirus), there have been about sixty reported cases, all tied to the countries on the peninsula for which it was named. Several cases have been reported in Europe, but so far, the illness hasn't seemed to have caught fire the way SARS did. The case fatality rate for the illness is a terrifying 50%, but this will likely drop as milder cases become trackable.

The real concern here is what the future holds, and how we can affect it. As noted above, the vigorous public health response to SARS helped control the spread, and the disease is essentially no longer seen. I'm a bit skeptical that the illness was all but eliminated by public health efforts alone. What essentially amounts to a deadly cold virus should not be that easy to contain.

The tracking and control of MERS-CoV may also depend on a mixture of good public health and biologic luck, but there are certainly areas of obvious concern. The Muslim pilgrimages, especially the Hajj, bring people from all over the world to the epicenter of the outbreak, sending them back to their home countries after potential exposure. Prevention of a pandemic will depend on the openness of a number of traditionally authoritarian states, not a particularly comforting idea.

It may be that MERS-CoV disappears mysteriously before the next Hajj season. Or maybe not. There are certainly too many unknowns. Hopefully the governments of the Arabian Peninsula will be willing to work openly with other states and the World Health Organization to learn as much as possible before a potential explosion of cases.

Peter A. Lipson, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. After graduating from Rush Medical College in Chicago, he completed his internal medicine residency at Northwestern Memorial Hospital. This post first appeared at his blog at Forbes. His blog, which has been around in various forms since 2007, offers "musings on the intersection of science, medicine, and culture." His writing focuses on the difference between science-based medicine and "everything else," but also speaks to the day-to-day practice of medicine, fatherhood, and whatever else migrates from his head to his keyboard.