“No region can be considered free from risk,” said the U.S. and Arab experts, including Saudia Arabia’s deputy minister for preventative medicine, in a study in the journal Science.

The pilgrimage itself, in the last week of November, provides perfect conditions for the spread of the H1N1 flu virus, which is transmitted in droplets and by physical contact.

“The density of pilgrims, the nature of the rituals, and the shoulder-to-shoulder contact recommended during prayers provide a perfect transmission atmosphere,” wrote Shahul Ebrahim of the U.S. Centers for Disease Control and Prevention and Ziad Memish of Saudi Arabia’s health ministry.

Around 3 million pilgrims from more than 160 countries take part in the haj in the holy city of Mecca most years, including up to 2 million who travel from abroad.

Memish and Ebrahim also said that after the event, around 45,000 pilgrims from Europe and more than 15,000 from North America will pass though major global airline hubs on their way home, further increasing the risk of spreading the virus.

“Haj-related exportation of H1N1 virus by returning pilgrims could potentially initiate waves of outbreaks worldwide and burden health care systems,” they wrote.

In an audio interview published with the research, Ebrahim said previous studies had shown “at least 30 to 35 percent spread of respiratory infections” during the haj.

“This year, because of the high levels of morbidity with H1N1 ... we are trying to be highly alert and highly prepared.”

Some pilgrims told “stay at home”

Health authorities have stopped counting the number of people who have caught swine flu but say many millions are likely to have been infected since it began to spread around the world in March.

It was declared a pandemic in June, and according to the World Health Organisation, as of Oct. 17 there were nearly 5,000 reported deaths worldwide from H1N1.

Arab health ministers agreed in July that they would try to prevent people aged over 65 and under 12 from travelling to Mecca for the haj, and several Muslim countries have advised pilgrims not to go this year.

Memish said authorities were also advising pregnant women and those with health risk factors such as diabetes, chronic heart, lung or kidney problems to stay at home.

Jeddah’s haj airport terminal, as well as sea ports and nearby airports, will have thermal sensors operating to check pilgrims and extra medical staff will be in place.

But the study’s authors said such measures may be only partly effective, since some H1N1 infected travellers may not yet be showing symptoms when they arrive, and others may contract the virus without getting a fever.

Ebrahim noted efforts by Saudi authorities to ensure “surge capacity” in hospitals in Jeddah and urged governments in pilgrims’ home countries to do the same.

“Resource-poor countries will need political will and external support to ensure availability of resources and logistics,” they said. “After Haj, surge capacity for returning pilgrims who might be ill should be ensured.”

Countries impose restrictions on Mecca pilgrimage

Waves of H1N1 flu spread by some three million pilgrims travelling to and from Mecca for November’s haj threaten to pile pressure on healthcare systems around the world, disease experts said on Thursday.

Several Muslim countries have imposed restrictions on the pilgrimage to Saudi Arabia because of worries about a major outbreak of H1N1 flu.

Here are some details:

·         EGYPT:

·         The most populous Arab state has decided to restrict umra and haj pilgrims to those over 25 and under 65. Egypt also plans to inoculate pilgrims against the H1N1 virus.

·         Egypt was the first Arab country to say that the haj and the ritual of umra were a threat to its citizens’ lives.

·         IRAQ:

·         The health ministry says haj travel is forbidden for sick people, pregnant women, people above 65 years of age, children under 12 and obese people.

·         It says it has assigned 330 doctors to go with people on the haj. While there, Iraqis will be assigned to 18 compounds where food will be prepared for them and in each compound there will be a clinic. Before going on haj one must have a checkup.

·         MOROCCO:

·         Morocco plans no restriction on travel for haj if the situation does not deteriorate in Saudi Arabia but has made it mandatory for its more than 30,000 pilgrims to get the anti-flu vaccine.

·         Authorities will allow pilgrims to travel for haj only when they have had their passports stamped by health officials to prove they have had their vaccination, officials said.

·         OMAN:

·         Oman issued an order on July 6 telling high-risk groups to postpone haj.

·         TUNISIA:

·         Tunisia has barred its citizens from making the annual pilgrimage to Mecca for the first time because of a lack of swine flu vaccines, the government said earlier this month.

·         The Ministry of Religious Affairs said a batch of H1N1 flu jabs would not arrive before mid-October, too late to ensure candidates for the pilgrimage, or haj, are vaccinated.

·         Tunisia is the first country formally to cancel the pilgrimage.