MERS-CoV, the Middle East Respiratory Syndrome coronavirus may spread faster and deeper internationally during two mass pilgrim gatherings taking place this year in Saudi Arabia, Dr. Kamran Khan, an infectious disease physician, of St. Michael’s Hospital, Toronto, Canada, and colleagues warned in the journal PLoS Currents: Outbreaks.

Two Muslim pilgrimages – Umrah and Hajj – attract millions of people from all over the world to the holy Saudi cities of Mecca and Medina.

Umrah can be done at any time of year. However, the bulk of travellers come during the month of Ramadan, which this year started on July 9th and ends on August 7th. Hajj, the major pilgrimage, takes place this year from October 13th to 18th.

Saudi Arabia expects over one million pilgrims from every corner of the globe during the next two to three weeks. In October, at least another three million will come.

Dr. Khan and colleagues are urging health care providers to learn from the experience of SARS. They emphasize that it is crucial for authorities and health care providers to anticipate rather than react to pilgrims coming home from the Middle East.

SARS was an unknown coronavirus that killed 800 people globally ten years ago. Forty-four people died in Toronto. The Canadian government says that SARS cost the nation’s economy approximately $2 billion.

The MERS coronavirus is also a previously unknown one. It appears to have emerged in the Middle East last year and has spread to several countries in the area, as well as Europe and North Africa. Cases of MERS-CoV infection have been reported in Saudi Arabia, Jordan, Qatar, United Arab Emirates, France, Italy, Tunisia, Germany and the Untied Kingdom.

Over 80 cases of MERS-CoV human infection have been confirmed worldwide, 42 of them died – MERS has a mortality rate of over 50%. SARS death rate was about 10%.

Dr. Khan and colleagues gathered and analyzed international airline traffic and historic Hajj data to predict how many people will be moving in and out of Saudi Arabia during these two mass pilgrimages. Their aim is to help countries assess MERS-CoV introduction by returning pilgrims and travellers.

The researchers also used economic and per capita health expenditure data collected from the World Bank to help determine how able countries might be to “detect imported MERS in a timely manner and mount an effective public health response.”

Dr. Khan is founder of a web-based technology – BioDiaspora – that predicts how infectious diseases can spread by analyzing global air traffic patterns. Several international agencies have used BioDiaspora to evaluate threats of emerging infectious diseases, including pilgrimages and sports events such as the Olympics. BioDiaspora has been used by WHO (World Health Organization), CDC (US Centers for Disease Control and Prevention) and ECDC (European Centre for Disease Prevention and Control).

Dr. Khan said:

“With millions of foreign pilgrims set to congregate in Mecca and Medina between Ramadan and the hajj, pilgrims could acquire and subsequently return to their home countries with MERS, either through direct exposure to the as-of-yet unidentified source or through contact with domestic pilgrims who may be infected.”

In this study, Khan and colleagues found that of the 16.8 million people who flew on commercial flights out of Saudi Arabia, Jordan, Qatar and the United Arab Emirates (where MERS-CoV cases have been traced back to) from June to November 2012 (one month before Ramadan and one month after Hajj last year), 51.6% travelled to just 8 countries:

16.3% – India

10.4% – Egypt

7.8% – Pakistan

4.3% – United Kingdom

3.6% – Kuwait

3.1% – Bangladesh

3.1% – Iran

2.9% – Bahrain

Between June and November 2012, each of the following twelve cities received at least 350,000 commercial air travelers from those four countries where MERS-CoV probably originated: