WHO announces the H1N1 pandemic is over

The World Health Organization (WHO) has declared that the H1N1 influenza pandemic is over and says that worldwide flu activity has returned to typical seasonal patterns.

The decision was taken at a meeting of the WHO Emergency Committee on 10 August 2010 and comes almost exactly 14 months after WHO moved to full phase 6 pandemic alert on 11 June 2009.

It is important to point out however that India and also parts of the southern hemisphere such as New Zealand are currently experiencing outbreaks of the pandemic strain H1N1 (2009) as part of their normal flu season. Thus, it is likely that we will see sporadic cases and outbreaks of H1N1 flu in Northern Ireland this coming winter given the well established travel links between UK and Ireland and India and Australasia.

Dr Lorraine Doherty, Assistant Director of Public Health (Health Protection) of the Public Health Agency, welcomes the announcement by WHO but strongly advises vigilance for H1N1 infection in this post- pandemic period when the behaviour of the H1N1 (2009) virus cannot be reliably predicted. In particular she highlights the following:

• Based on what we know from previous pandemics and of the available evidence in relation to H1N1 in the southern hemisphere, it is likely that this virus will continue to cause serious disease in younger age-groups and in groups who are known to be at high risk of severe or fatal illness such as pregnant women.

• It is important that we maintain our surveillance for flu and flu-like illness and severe respiratory infections. The PHA have already put these arrangements in place and these will be maintained.

• Immunisation is an essential component of reducing influenza infections particularly in vulnerable groups. This year’s seasonal flu vaccine will cover the H1N1 (2009) virus. The Department has recently issued guidance on the flu immunisation programme for 2010/11 and the PHA are leading the implementation arrangements for this programme. It remains just as important this year as last year to ensure that those most at risk of influenza infection and its complications are immunised, including pregnant women, in line with departmental guidance. http://www.dhsspsni.gov.uk/hss-md-31-2010.pdf

• Antivirals will remain available for treatment when influenza virus is demonstrated to be circulating in the community and implementation of the NICE guidance on prescription of antivirals is appropriate.

Pandemics, as we know are, unpredictable. It is essential that we maintain our vigilance for influenza infections, our close attention to prevention measures and update our preparedness plans.