After an emergency meeting recently, the World Health Organisation (WHO) is urging countries to be more vigilant against the Middle East respiratory syndrome (Mers) coronavirus.
More than 500 confirmed Mers cases are all connected to the Middle East, and the virus has been exported to several countries.
The world health agency became more concerned after April saw a spike of 288 Mers cases compared to 207 confirmed cases from March 2012 - when Mers first emerged - up to March this year. In Jeddah, there were 135 cases in April alone, compared to just four in the previous two years.
However, WHO says an epidemic is not yet imminent.
That means the recent surge in cases does not indicate that the virus has mutated into a form more transmissible from person to person. The uptick is probably a seasonal increase in the number of primary cases, it says.
These are people infected with Mers from animals, likely camels which themselves were likely to have been infected by bats.
The seasonal increase may be related, in this instance, to the movement of large numbers of camels both to and from Saudi Arabia's Hafr Al-Batin region for a large annual camel fair.
But this seasonal increase in primary cases of animals infecting humans may be further amplified when patients then infect health-care workers - if hospitals are slack in their infection prevention and control measures.
Still, within the community at large, Mers is not being transmitted rapidly from person to person for now.