As MERS-CoV case count rises, search for animal reservoir continues

January 12th, 2015

The novel coronavirus which emerged in the Middle East, now officially called MERS-CoV (Middle East respiratory syndrome coronavirus), continues to cause new, often fatal infections.

As of June 2, 2013, there were a total of 53 laboratory-confirmed cases of infection with MERS-CoV, including 30 deaths, the World Health Organization reported.¹ At that time, the WHO reported two new laboratory-confirmed cases with (MERS-CoV) in Italy. Both patients were close contacts of a laboratory-confirmed case with recent travel to Jordan. The patients -- a two-year-old girl and a 42-year-old woman – were in stable condition.

In additional data on the 44 confirmed MERS-CoV case of May 23, 2013, Saudi Arabia accounted the most cases by far, with 30 confirmed infections and 17 fatalities. Cases have also been detected in Jordan, Qatar, Tunisia, the United Arab Emirates, Germany, Britain and France. Jordan, Qatar, United Arab Emirates, and Saudi Arabia have each had authochthonous cases and Germany, France, Tunisia and the United Kingdom have had cases associated with travel or contact with a returned infected traveler.

The median age of the cases was 56 years, ranging from 24 to 94 years; 79% were male.

Sporadic cases in the community without known exposure have occurred, as well cases resulting from contact with family members. Person-to-person spread within healthcare facilities has occurred. A cluster of cases at Al-Moosa General Hospital -- a 150-bed facility in Hofuf in the Al-Ahsa region of the Eastern province of Saudi Arabia -- involved 22 patients, with the first identified on April 24 and the last on May 1. Ten of the 22 have died. Cases occurred in family members of patients, as well as in healthcare workers.

Coronaviruses infect a variety of mammals. The natural reservoir of the 2003 SARS coronavirus was the horseshoe bat, while palm civets acted as intermediate hosts. Though bats are suspected by many, the reservoir of the MERS-CoV has not been determined at the time of this writing. It seems likely that camels are an important reservoir. A73-year-old male from Abu-Dhabi who died in a hospital in Munich, Germany on Mar 26, 2013 had been exposed to one of his racing camels that was sick. A variety of animal specimens are being examined for evidence of infection.

-- Stan Deresinski, MD, FACP, FIDSA, Clinical Professor of Medicine, Stanford University, Hospital Epidemiologist, Sequoia Hospital, Redwood City, CA.

For more on this story see the July 2013 issue of Infectious Disease Alert