The incubation period of the Sars-like virus that has killed 30 people globally, mainly in Saudi Arabia, may be longer than previously thought, requiring longer quarantine, a study says.
The Middle East Respiratory Syndrome coronavirus (MERS-CoV) may have an incubation - the period between infection and symptoms - of nine to 12 days, longer than the one-to-nine-day period previously observed.
This finding has "important implications for the duration of the quarantine required to rule out infection among contacts" of the patient, says the study published on Wednesday in The Lancet medical journal.
People who return from the Middle East with respiratory ailments, or who had been exposed to a confirmed MERS case, should be isolated, said the team and recommended a period of at least 12 days to confirm they were clear of the virus.
A team of researchers had examined two French MERS patients for the latest study. One, who has since died, was apparently infected while travelling in Dubai, and the second seems to have caught it while sharing a hospital room with the first - before doctors detected the virus.
Saudi Arabia yesterday reported that three more people had died, bringing the total number of deaths globally to 30.
The disease is a cousin of the severe acute respiratory syndrome (Sars) that sparked a global health scare in 2003 when it leapt from animals to humans in Asia and killed 800 people, 299 in Hong Kong.
Like Sars, the new virus appears to cause a lung infection, with patients suffering from a fever, cough and breathing difficulty. But it differs from Sars in that it also causes rapid kidney failure.
Health officials worry about the high death rate of about 50 per cent, warning the disease could spark a new crisis if it acquires an ability to spread easily between humans.