# 5152
Given the recent reports of severe influenza cases occurring in the UK, for the next few weeks I’ll try to feature the Health Protection Agency’s (HPA) Weekly Influenza Report along with my usual coverage of the CDC’s FluView report.
You can download this week’s report as a PDF File at:
HPA Weekly National Influenza Report - week 50 (2010) (PDF, 317 KB)
Links, and some excerpts from today’s report follow (bolding and reparagraphing added):
HPA National Influenza Report
Summary
Influenza activity is increasing; GP consultation rates are now above baseline levels in England. Outbreaks and severe cases, mainly in people aged under 65 years, continue to be reported.
Influenza A H1N1 (2009) and B are the predominant circulating viruses with few, sporadic A (H3N2) viruses detected.
The H1N1 (2009) virus strain is virologically and epidemiologically similar to that seen during the pandemic. The virus strains circulating are well matched to the current influenza vaccine and very little antiviral resistance has been detected. The HPA expects to see continued elevated influenza activity for several weeks.
- In week 49 (ending 12 December), the weekly influenza/influenza-like illness (ILI) consultation rates increased to above baseline levels in England (34.6 per 100,000). The rates have increased but remain below the baseline in Wales (22.5 per 100,000), Scotland (36.1 per 100,000) and Northern Ireland (29.2 per 100,000). Consultation rates for acute bronchitis also increased.
- Fifty-seven acute respiratory disease outbreaks were reported in UK in week 49, 55 schools, one care home and one hospital. This brings the total reported this season so far to 88.
- Eighty-four of 149 (56.4%) specimens from patients with ILI presenting to sentinel GPs in England in week 49, were reported as positive for influenza. The proportion of specimens reported to DataMart (England) as positive for influenza has increased to 26.9% (355 of 1,320). The proportion of samples positive for RSV and rhinovirus are decreasing.
- All influenza viruses characterised have been found to be similar to the vaccine strains.
- Severe cases requiring ICU/ECMO admission have been reported. From week 36, 17 deaths associated with influenza infection have been reported. The majority of severe cases reported are aged under 65.
<SNIP>
Microbiological surveillance
The majority of influenza viruses detected have been influenza A H1N1 (2009) and influenza B with few influenza A (H3N2) viruses.
Of 1,320 respiratory specimens reported to the English Data Mart system as taken in week 49, 355 (26.9%) were positive for influenza (271 H1N1 (2009), seven influenza A not subtyped and 77 influenza B) (figure 7).
The proportion positive for respiratory syncytial virus (RSV) and rhinovirus have decreased (from 23.2% to 16.1% and 13.6% to 9.5% respectively).
Figure 7: DataMart samples positive for influenza, England
To try to put the current level of influenza-like-illness activity into perspective, I’ve selected a graph from the HPA’s Influenza Surveillance Graphs pdf file.
The consultation rate for ILIs (influenza-like Illnesses) in the UK have more than doubled over the past week, illustrating just how quickly the situation can change.
As chart below shows - while elevated and rising - so far the rate is still well below what was seen during the peak of the 2009 pandemic, or during the extremely severe flu season of 1999-2000.
The red line indicates this year’s activity.
While I was working on putting this post together, Robert Roos of CIDRAP posted a useful overview of today’s influenza surveillance report which you can read at:
UK leads way as flu activity rises in Europe
Robert Roos
News Editor
Dec 16, 2010 (CIDRAP News) – The United Kingdom is on the leading edge of an increase in influenza activity in Europe, with 57 respiratory disease outbreaks and an increase in critically ill patients and deaths reported in the country last week, according to the UK Health Protection Agency (HPA).
