Travel health advice is being given to anyone considering a trip abroad who is concerned about the growing threat of a swine flu pandemic.
Non-essential travel to Mexico is currently discouraged by the Foreign and Commonwealth Office (FCO), which is also advising British nationals who are holidaying in the country to reassess whether they should cut short their trip.
The World Health Organisation (WHO) announced earlier this week (April 29th) that it was increasing its pandemic alert from phase four to phase five.
It also impressed upon manufacturers of antiviral drugs to increase production in light of the current crisis.
Influenza vaccine manufacturers have also been urged to concentrate their resources on establishing a vaccine.
WHO director-general Dr Margaret Chan commented: "This change to a higher phase of alert is a signal to governments, to ministries of health and other ministries, to the pharmaceutical industry and the business community that certain actions should now be undertaken with increased urgency and at an accelerated pace."