On June 11, 2009, the World Health Organisation (WHO) raised the level of influenza pandemic for H1N1 (2009) alert from phase 5 to phase 6.

WHO considered that at this early stage, the pandemic can be characterised globally as being moderate in severity.

Countries were advised to assess their specific situation and make a timely transition from focusing national efforts on containment to focusing on mitigation measures.

In calibrating Singapore's Disease Outbreak Response System Alert (DORSCON) level to Yellow on May 11, Singapore has already taken into account the above development.

In terms of control measures, Singapore will be in containment mode for as long as it is practical to do so, and for as long as there is no community spread here, the Ministry of Health (MOH) said in a statement.

MOH says social responsibility and high standard of personal hygiene from all of us is still the most important and practical measure against H1N1 infection.

However, with a level 6 pandemic, the shift to mitigation measures may be inevitable.

H1N1 has so far been reported in 74 countries and it may be a matter of time that it spreads in Singapore.

To prepare, Singapore will gradually pace the shift of its control strategy from containment, i.e. "stopping the spread of the virus" to mitigation, i.e. "caring for those who fall ill".