Explosion of UK Pandemic H1N1 Cases Raise Concerns

Commentary

Recombinomics Commentary 16:02
July 24, 2009

Produced by Nottingham University's Division of Primary Care the figures show the rate of infections recorded in GPs' surgeries across England, Wales and Northern Ireland. You can see from this exactly how bad Tower Hamlets is - and which areas have the lowest rates.

The above comments describe the newly released data on the location of pandemic H1N1 cases in the UK. The 49,611 cases have been added to the map of confirmed and probable cases to provide a snapshot of cases a week ago. There have been an additional 100,000 cases reported in the latest HPA report.

These data compliment the reports from the HPA, which had issued daily reports through July 2. At that time confirmed cases were in the range of 600 per day, and reporting was switched to a weekly schedule. However, the July 9 report did not show confirmed cases beyond July 2. Moreover, the July 16 weekly report also failed to include any confirmed cases after July 2, although the ILI (influenza like illness) graph continued to show an alarming explosion of cases. These increases in cases were accompanied by a jump in fatalities, but there was little information on the location of these cases.

The release of the rates of ILI by location allowed for mapping of the cases throughout the UK, including a detailed map of outbreaks in the Greater London area.

These cases have put a strain on emergency services and at least one patient was flown to Sweden for treatment due to a lack of hospital beds and specialized treatment for critical cases.

It remains unclear if the explosion in cases in the UK is linked to genetic changes. Influenza season in the northern hemisphere is begins in the fall and peaks in February, in marked contrast to the current pandemic. The persistence and spread of cases in the summer may be linked to an avian PB2, which is adapted to the body temperature of birds (41 C).

However, the explosion of cases in the UK raises concerns of additional genetic changes.

The rise in cases began in the West Midlands several weeks ago, and the number of H1N1 sequences released by the UK has been limited. Recently Argentina announced that H1N1 associated with the explosion of cases and fatalities in Argentina has 8 amino acid changes.

Release of series of H1N1 sequences from the UK and Argentina would be useful. Further adaptation to human hosts is expected and the increases in cases and fatalities may reflect minor genetic changes that produces significant changes in transmission and virulence.

The sudden jump in cases and deaths are growing causes of concern.