Fears of an outbreak of the deadly MERS virus in Saudi Arabia and construction in the holy city of Mecca have forced cuts in the numbers of pilgrims permitted to perform this year's hajj.
Millions of Muslims during the annual pilgrimage head to Mecca and Medina, Islam's two holiest sites, providing a possible means for MERS to spread around the globe as pilgrims who may become infected return to their home countries.
Fearful of such a scenario, the authorities have reduced by half the number of pilgrims coming from within Saudi Arabia, and by about 20 per cent those from abroad.
"This is an exceptional and temporary decision," Hajj Minister Bandar Hajjar announced last month.
MERS, short for Middle East Respiratory Syndrome coronavirus which can lead to acute pneumonis and renal failure, claimed its first victim in Saudi Arabia in June 2012.
Saudi Arabia, which has already recorded 69 MERS cases, 38 of whom have died, has urged the elderly and chronically ill, as well as children and pregnant women, not to perform the annual hajj that falls this year in October.
But the health ministry so far has not taken any special measures at airports to detect visitors who may be infected with MERS, deputy health minister Ziad Memish told AFP.
"We have not taken any precautionary measures at airports since the World Health Organisation has not recommended them," he said.
WHO health security chief Keiji Fukuda said the organisation would issue general guidelines aimed at minimising the risk of infections spreading.
"We do recognise that this is a risk for travellers and that there are certain steps that individual travellers and countries can take, for example for people who have serious medical conditions," Fukuda told reporters.
Since then, a total of 90 cases and 45 confirmed MERS deaths have been recorded worldwide, in countries including Jordan, Qatar and the United Arab Emirates, Tunisia, Britain, France and Italy.
But most cases have been reported in Saudi Arabia.
Experts are struggling to understand MERS, for which there is no vaccine.
MERS does not appear to spread easily but currently has an extremely high fatality rate of 55 percent. It is a cousin of SARS, which erupted in Asia in 2003 and infected 8,273 people, nine percent of whom died.
Like SARS, MERS is thought to have jumped from animals to humans, and shares the former's flu-like symptoms but differs by causing kidney failure.
