Mecca pilgrimage
© Associated Press/Hassan AmmarMore than two million Muslims descend on Mecca for the annual Hajj each year. Saudi authorities are advising pilgrims to wear face masks in overcrowded places
As Saudi and U.N. health authorities report new infections from a troubling new respiratory disease, there are concerns that the approaching Hajj - the annual Muslim pilgrimage to Mecca - could increase the risk of spreading the virus as pilgrims return to their home countries.

Meanwhile the U.S. government, in a notice published in the Federal Register Wednesday, declared that the Middle East respiratory syndrome coronavirus (MERS-CoV, or simply MERS) could potentially "affect national security or the health and security of United States citizens living abroad."

Saudi Arabia is currently the undisputed center of the scare.

According to the Centers for Disease Control and Prevention (CDC) the majority of the 55 confirmed MERS cases - 40 infections, 24 deaths - have occurred in the kingdom, while two deaths each have been reported in Britain and Jordan and one death each in France and the United Arab Emirates. (The fatalities in Europe were linked to visits to the Middle East.)

Infections also have been reported in Qatar, Tunisia and Italy.

coronavirus
© Associated Press/Health Protection AgencyThis undated image released by the British Health Protection Agency shows an electron microscope image of a coronavirus
The notice published in the Federal Register Wednesday said Health and Human Services Secretary Kathleen Sebelius has determined that "there is a significant potential for a public health emergency that has a significant potential to affect national security or the health and security of United States citizens living abroad."

That determination in turn allows the Food and Drug Administration (FDA) to bypass standard processes and fast-track approval for products or drugs in relation to MERS, on the basis of an "emergency use application" (EUA).

The FDA may under the prescribed circumstances issue an EUA "authorizing (1) the emergency use of an unapproved drug, an unapproved or uncleared device, or an unlicensed biological product; or (2) an unapproved use of an approved drug, approved or cleared device, or licensed biological product," the notice says.

Saudi Arabia says more than two million Muslims - including roughly 20,000 from the United States - visit Mecca for the Hajj, which brings large numbers of people into close proximity in a confined geographical area over a five-day period. This year's pilgrimage falls in mid-October.

As of Wednesday, the U.N. World Health Organization (WHO) said it was not advising any "special screening at points of entry" as a result of the outbreak, "nor does it currently recommend the application of any travel or trade restrictions."

Updated guidelines for Hajj pilgrims, issued by the Saudi Embassy in Washington, make no mention of MERS in a section on health issues and vaccination requirements. Vaccinations that are required for adults include those for meningitis, seasonal flu, and the H1N1 flu virus.

The guidelines do include an unspecific warning: "Health experts advise the following groups to postpone their plans for Hajj and Umrah this year for their own safety: The elderly, the terminally ill, pregnant women, and children." (The Umrah is a secondary type of pilgrimage to Mecca, one that can be taken any time of the year.)

In its health guidelines related to MERS, the Saudi health ministry has one reference to the pilgrimage, advising the wearing of face masks "in the overcrowded places during Hajj or Umrah."

A Malaysian study published in the Journal of Travel Medicine in 2010 found that more than 60 percent of Malaysian pilgrims developed respiratory systems, including coughs, sore throats and fever, during the 2007 Hajj.

A French study, published in the same journal and examining French pilgrims at the 2009 Hajj, found that although almost 80 percent reported having worn face masks, their use "did not significantly reduce respiratory symptoms."

The most recent fatality reported to WHO by Saudi health authorities is that of a 14 year-old girl. It was noted that she is not from an area in the east of the kingdom called Al-Ahsa, where a cluster of cases at one hospital since April accounted for 22 infections and 10 deaths.

According to the CDC, there have been no reports of anyone in the U.S. becoming infected with the virus, whose symptoms can include cause coughing, fever and pneumonia.

'Alarming'

Much about the virus is unknown, including its origin (bats are a suspected host), how infections are occurring, the conditions under which it could spread from one person to another, and chances of mutation into a more easily-transmissible form.

Experts say it is distinct from, but similar to, Severe Acute Respiratory Syndrome (SARS), which was blamed for 774 deaths between late 2002 and mid-2003, more than 80 percent of them in mainland China and Hong Kong.

"Although the number of cases documented is limited, the morbidity and mortality of the infection is alarming, as is its uncanny resemblance - at least in its clinical features - to SARS," the Coronavirus Study Group (CSG) of the International Committee on Taxonomy of Viruses said in a report in May, at a time when the number of confirmed MERS infections stood at 30.

"While a small minority of the known cases developed mild disease, most patients presented with a severe acute respiratory condition requiring hospitalization; the mortality rate is approximately 60 percent," the CSG said. (The mortality rate currently is about 55 percent).

While WHO has not issued travel or screening advisories, it is encouraging vigilance, saying travelers returning from the Middle East who develop severe acute respiratory infections should be tested for MERS.

WHO is also advising clinicians that in patients whose immunity is compromised, MERS infection should be considered, even in cases of atypical symptoms, such as diarrhea.