2010-2012: HPA Weekly National Influenza Report Weeks 49 - 26: 607 fatalities confirmed

[Ronan Kelly]

HPA Weekly National Influenza Report
Summary of UK surveillance of influenza and other seasonal respiratory
illnesses
9 December 2010 ? Week 49

Summary
Influenza activity is increasing across the UK. Although GP consultation rates remain low, several outbreaks and severe, hospitalised cases have been reported.
In week 48 (ending 5 December), the weekly influenza/influenza-like illness (ILI) consultation rates increased slightly in England (13.3 per 100,000) and Wales (10.5 per 100,000), while decreasing in Scotland (28.8 per 100,000) and Northern Ireland (21.0 per 100,000). All GP consultation rates are within baseline levels. Consultation rates for acute bronchitis and pneumonia slightly increased.
Nine acute respiratory disease outbreaks were reported in UK in week 48, eight (three influenza B and one H1N1) were reported from schools and one influenza H1N1 from a military base. This brings the total reported this season so far to 31.
Twenty nine of 86 (33.7%) specimens from patients with ILI presenting to sentinel GPs in England in week 48, were reported as positive for influenza (eighteen influenza A H1N1 (2009), one influenza A not subtyped and ten influenza B). The proportion of specimens reported to DataMart as positive for
influenza has increased to 16.7% (151 of 903).
The proportion of samples positive for respiratory syncytial virus (RSV) and rhinovirus remains high, though is decreasing for rhinovirus.
All influenza B and H1N1 (2009) viruses characterised have been found to be similar to the vaccine strains.
By week 48, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 66.1%. For those aged in a risk group aged under 65 it was 40.2%.
Worldwide, influenza activity remains low, except in areas of South Asia and central and western Africa, which have seen recent surges in influenza H1N1 (2009) virus detections. Most countries in the temperate zone of the northern hemisphere continued to report low activity levels. Except for a few countries in Southeast Asia, most countries in the tropics of the Americas and Asia have recently reported low levels of influenza activity. Globally, there continued to be co-circulation of influenza H1N1 (2009), A(H3N2), B viruses, with the latter two being predominant.

......

Of 903 respiratory specimens reported to the English Data Mart system as taken in week 48, 151 (16.7%) were positive for influenza (102 H1N1 (2009), five influenza A not subtyped and 44 influenza B) (figure 7). Detections of respiratory syncytial virus (RSV) remain high; the proportion positive was stable at 24% in week 48. Rhinovirus detections have decreased; the proportion positive decreased from 18.4% to 14.3% in the same time period.
Of the 86 samples submitted via the two English GP-based sentinel schemes in week 48, 29 (33.7%) were positive for influenza (one influenza A H3, 18 influenza H1N1 (2009) and ten influenza B) (table 1).
In week 48, five specimens were reported as positive for influenza through the sentinel GP scheme in Scotland (table 1).

....

Of 74 influenza H1N1 (2009) viruses tested for antiviral susceptibility since week 40 2010, one has been found to carry the H275Y mutation which confers resistance to the antiviral drug oseltamivir. Four further H1N1 (2009) viruses, two influenza A H3 viruses and five influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

...

Several severe cases of influenza have been reported in the last two weeks resulting in an increase in ITU-bed occupancy and in the provision of beds used for Extra-Corporeal Membrane Oxygenation (ECMO). The majority of these patients are aged under 65 years. Since week 36, ten deaths associated with influenza infection have been reported in the UK. None of the five fatal cases with information available had received the 2010/11 seasonal influenza, or the 2009 monovalent pandemic influenza vaccine.

....

Full report at; http://www.hpa.org.uk/web/HPAwebFile.../1287146267647

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Week 49

HPA Weekly National Influenza Report
Summary of UK surveillance of influenza and other seasonal respiratory
illnesses
16 December 2010 ? Week 50

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.
By week 48, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 67.2%. For those aged in a risk group aged under 65 it was 41.6%.
On 10 December 2010 the UK Department of Health issued a letter to NHS staff in England to inform them that in line with the National Institute of Clinical Excellence guidance, the use of antiviral drugs for the prevention or treatment of influenza is now recommended.
In Europe most countries are reporting low activity. In the USA most indicators are showing low activity while in Canada overall influenza activity has increased.

.....


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).
Of the 149 samples submitted via the two English GP-based sentinel schemes in week 49, 84 (56.4%) were positive for influenza (56 influenza H1N1 (2009) and 28 influenza B) (table 1). In week 49, one specimen was reported as positive for influenza through the sentinel GP scheme in Northern Ireland (table 1).

....

Of 109 influenza H1N1 (2009) viruses reported as tested for antiviral susceptibility at RVU and regional labs since week 40 2010, one has been found to carry the H275Y mutation which confers resistance to the antiviral drug oseltamivir. Five further H1N1 (2009) viruses, two influenza A H3 viruses and five influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

....

There have been reports of influenza hospitalisations and ICU admissions across the UK. Twenty-two H1N1 (2009) patients have been referred for ECMO up until 15 December 2010. Of these, 17 have received ECMO. All cases receiving ECMO have been adults under 65 years in age (median=39 years, IQR 35-45 years). Four of the 17 (23.5%) cases were pregnant.

A number of influenza-related deaths have been reported to HPA from across the UK. From week 36 to 16 December 2010, 17 fatal cases have been verified by HPA as related to influenza infection. These will not represent all influenza-related deaths. Of these verified fatal cases, 14 have been associated with H1N1 (2009) infection and 3 with influenza B infection. All cases have been under 65 years in age (median age =33 years, IQR= 8-45 years) and six were aged under 18 years. At least eight of the 17 fatal cases were in one of the CMO-defined clinical risk groups for vaccination but none were pregnant. Of the 14 cases with available information on immunisation, none had received either trivalent influenza vaccination this season, or pandemic influenza vaccination last year. Information is still being sought from the remaining cases.

full report at; http://www.hpa.org.uk/web/HPAwebFile.../1287146386672

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 50

HPA Weekly National Influenza Report
Summary of UK surveillance of influenza and other seasonal respiratory
illnesses
23 December 2010 ? Week 51

Summary
Influenza activity continues to increase across the UK; GP consultation rates are now above baseline levels in England and Wales. Increasing numbers of severe cases, mainly in people aged under 65 years are being 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 overall well matched to the current influenza
vaccine. The HPA expects to see continued elevated influenza activity for several weeks.
In week 50 (ending 19 December), the weekly ILI consultation rates increased across the UK (figure 1). The weekly influenza/influenza-like illness (ILI) consultation rates remain above baseline levels in England (87.1 per 100,000). The rates have increased above the baseline in Wales (85.6 per 100,000), but remain below baseline in Scotland (45.8 per 100,000) and Northern Ireland (64.6 per 100,000).
Thirty-two acute respiratory disease outbreaks were reported in UK in week 50, 29 in schools, one in a nursery, one in a hospital and one in a prison. This brings the total reported this season so far to 120.
One-hundred and sixty eight of 256 (65.6%) specimens from patients with ILI presenting to sentinel GPs in England in week 50, were reported as positive for influenza. The proportion of specimens reported to DataMart (England) as positive for influenza has increased to 38.9% (1031 of 2,648). The proportion of samples positive for RSV and rhinovirus is decreasing. Currently the main circulating influenza strains are influenza A (H1N1) and influenza B.
Severe cases requiring ICU/ECMO admission have been reported. From week 36, 27 deaths associated with influenza infection have been reported. The majority of fatal cases reported were unimmunised.
By week 50, the proportion of people in England aged over 65 years who had received the 2010/11
influenza vaccine was 68.5%. For those in a risk group aged under 65 it was 43.0%.
On 21 December 2010 the UK Department of Health issued a letter to NHS staff in England to inform them that the use of antiviral drugs for the prevention or treatment of influenza is now recommended for any patient who is at risk from developing complications from influenza. More information is available at https://www.cas.dh.gov.uk/ViewandAck...AlertID=101515.
In Europe most countries are starting to report early influenza activity. In the USA and Canada overall influenza activity has increased.

....

Of 2,648 respiratory specimens reported to the English Data Mart system as taken in week 50, 1031 (38.9%) were positive for influenza (765 were H1N1 (2009), 33 influenza A not subtyped and 233 influenza B) (figure 7). The highest age-specific positivity rate for H1N1 2009 was 39.8% in 15-44 year olds, and for influenza B it was 28.4% in 5-14 year olds. The proportion positive for respiratory syncytial virus (RSV) and rhinovirus have decreased (from 16.1% to 11.9% and 9.3% to 5.5% respectively).
Of the 256 samples submitted via the two English GP-based sentinel schemes in week 50, 168 (65.6%) were positive for influenza (114 influenza H1N1 (2009), 53 influenza B and 1 influenza A, unknown subtype) (Table 1).
In week 50, 12 specimens were reported as positive for influenza through the sentinel GP scheme in Scotland, and 10 specimens were reported positive for influenza in Northern Ireland (table 1).

....

Of 405 influenza H1N1 (2009) viruses reported as tested for antiviral susceptibility at RVU and regional labs since week 40 2010, three have been found to carry the H275Y mutation which confers resistance to the antiviral drug oseltamivir. Five further H1N1 (2009) viruses, two influenza A H3 viruses and five influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

....

Disease severity and mortality data
There have been reports of influenza hospitalisations and ICU admissions across the UK. Up to week 51, 62 new hospitalised H1N1 confirmed cases have been recruited to the MOSAIC study from hospitals in London and Liverpool. The average age is 36 years, with only one case >60 years of age and 11 are children. Of 27 adult women, 8 were pregnant. Asthma and obesity appear to be risk factors for severe disease. No patient received antivirals prior to hospital admission. More details on the MOSAIC study are available at http://clinicaltrials.gov/ct2/show/NCT00965354. Information collected from the units providing adult respiratory ECMO show that currently there are 16 adult patients being treated with respiratory ECMO. Of these patients all but one are H1N1 positive. There are 3 children now being treated with respiratory ECMO of whom 1 is H1N1 positive.

HPA is receiving reports of fatal influenza cases from various sources (clinicians, laboratory reports and death certificates). These reports have been reconciled and verified with clinicians. These will not represent all influenza-related deaths. From week 36 to 22 December 2010, 27 fatal cases have been verified by HPA as related to influenza infection in the UK. Of these verified fatal cases, 24 have been associated with H1N1 (2009) infection and 3 with influenza B infection. All cases have been under 65 years in age (median age =33 years, IQR= 8-45 years, range 1 to 55 years). Nine (33%) cases were aged under 18 years. Twelve (46%) of the 26 fatal cases with information available were in one of the CMO-defined clinical risk groups for vaccination. Of cases with available information on immunisation uptake, 21 out of 22 had not received trivalent influenza vaccination this season and 20 out of 21 had not received pandemic influenza vaccination last year.

In week 49, an estimated 11,193 all-cause deaths were registered in England and Wales (source: Office for National Statistics), an increase from the previous week and now above the upper limit of expected levels for this time of year (figure 8). Potential factors for this increase include recent cold weather and circulating respiratory viruses.

full report at; http://www.hpa.org.uk/web/HPAwebFile.../1287146883984

[Hogweed]

Re: HPA Weekly National Influenza Report Weeks 49 - 51

Full report and PDF with charts at link

http://www.hpa.org.uk/web/HPAweb&HPAwebStandard/HPAweb_C/1287147913271

Report published 30 December 2010 (Week 52)
Summary

Influenza activity continues to increase across the UK. GP consultation rates are now above baseline levels in all four countries. 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 overall well matched to the current influenza vaccine. The HPA expects to see continued elevated influenza activity for several weeks.

* In week 51 (ending 26 December), the weekly ILI consultation rates increased across the UK. The weekly influenza/influenza-like illness (ILI) consultation rates remain above baseline levels in England (124.4 per 100,000) and Wales (92.1 per 100,000). The rates have now increased above the baseline in Scotland (58.4 per 100,000) and Northern Ireland (99.4 per 100,000).
* The weekly national proportion of NHS Direct cold/flu calls for week 51 has increased however, the daily proportion has decreased slightly to 10.4% on 28 December, from a peak of 12.9% on 21 December. The proportion of calls for fever in the 5-14 year age group decreased from 21.6% to 16.8%, though this remains above the baseline level of 9%. This suggests the possiblity that we may be approaching the peak of influenza activity.
* Two acute respiratory disease outbreaks were reported in UK in week 51, one in a primary school and in a prison. This brings the total reported this season so far to 122. It should be noted that most schools across the UK were on holiday in week 51.
* One-hundred and twenty-six of 189 (66.7%) specimens from patients with ILI presenting to sentinel GPs in England in week 51, were reported as positive for influenza. The proportion of specimens reported to DataMart (England) as positive for influenza has increased to 43.2% (1.711 of 3,959). The proportion of samples positive for RSV and rhinovirus is stable or decreasing.
* Currently the main circulating influenza strains are influenza A (H1N1) and influenza B.
* From week 36, 39 deaths associated with influenza infection have been reported. The majority of fatal cases reported were unimmunised.
* By week 50, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 68.5%. For those in a risk group aged under 65 it was 43.0%.
* On 21 December 2010 the UK Department of Health issued a letter to NHS staff in England to inform them that the use of antiviral drugs is recommended for treatment of influenza in high risk patients.
* In Europe most countries are starting to report early influenza activity. In the USA and Canada overall influenza activity has increased.


- Full report and PDF with charts at link above

-Comment. The chart and figures for excess deaths has not been updated since last week. The same chart as last week is shown. So it still says.

In week 49, an estimated 11,193 all-cause deaths were registered in England and Wales (source: Office for National Statistics), an increase from the previous week and now above the upper limit of expected levels for this time of year (figure 8). Potential factors for this increase include recent cold weather and circulating respiratory viruses.


Figure 8: Observed and predicted all-cause mortality


- I hope the missing data on deaths is due to a delay in reporting and not because someone wants to hide something. Would be nice to know if last week was a blip or if the rise in death rate has continued the last week.

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 51

From Hogweed's link; my comments in blue

...

Of 3,959 respiratory specimens reported to the English Data Mart system as taken in week 51, 1,711 (43.2%, increased from 38.9% in week 50) were positive for influenza (1,402 H1N1 (2009), 41 influenza A not subtyped and 268 influenza B) (figure 7). The highest age-specific positivity rate for H1N1 2009 was 45.2% in 15- 44 year olds, and for influenza B it was 29.3% in 5-14 year olds. The proportion positive for respiratory syncytial virus (RSV) remains stable at 11.8% and for rhinovirus is decreased from 5.3% to 3.7%.

Of the 189 samples submitted via the two English GP-based sentinel schemes in week 51, 126 (66.7%) were positive for influenza (104 influenza H1N1 (2009), 21 influenza B and 1 influenza A, unknown subtype) (Table 1).
In week 51, 31 specimens were reported as positive for influenza (17 H1N1 (2009), one A unknown subtype and 13 influenza B) through the sentinel GP scheme in Scotland, and 10 specimens were reported positive for influenza H1N1 (2009) in Northern Ireland (table 1).

...

Of 336 (this number was reported as 405 last week including regional labs) influenza H1N1 (2009) viruses reported as tested for antiviral susceptibility at RVU (not including regional labs) since week 40 2010, six have been found to carry the H275Y mutation which confers resistance to the antiviral drug oseltamivir (that's 3 more than last week) . Five H1N1 (2009) viruses, two influenza A H3 viruses and five influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

...

HPA is receiving reports of fatal influenza cases from various sources (clinicians, laboratory reports and death certificates). These reports have been reconciled and verified with clinicians. These will not represent all influenza-related deaths. Up to 29 December 2010, 39 fatal cases have been
verified by HPA as related to influenza infection in the UK. Of these verified fatal cases, 36 have been associated with H1N1 (2009) infection and 3 with influenza B infection. All except one case has been under 65 years in age (mean age = 34.6 years; median age =42 years, range 1 to 74 years). Four
cases were aged less than five years of age. Twenty-three of the 38 fatal cases with available information (61%) were in one of the CMO-defined clinical risk groups for vaccination. Of cases with available information on immunisation history, 31 of 33 cases (94%) had not received trivalent influenza vaccination this season and 29 of 30 cases had not received
pandemic influenza vaccination last season.
...

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 51

HPA Weekly National Influenza Report
Summary of UK surveillance of influenza and other seasonal respiratory
illnesses
6 January 2011 ? Week 1

Summary
GP and school closures over the Christmas period will have affected surveillance indicators so all data should be interpreted with caution. Indeed, several influenza indicators have apparently plateaued. GP consultation rates remain above baseline levels in all four countries. 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 overall well matched to the current influenza vaccine.
In week 52 (ending 26 December), the weekly influenza/influenza-like illness (ILI) consultation rates decreased in England (98.4 per 100,000) and Scotland (52.0 per 100,000), were stable in Wales (89.2 per 100,000) and increased in Northern Ireland (179.5 per 100,000).The weekly national proportions of NHS Direct calls for cold/flu and fever have decreased in week 52.
Thirteen acute respiratory disease outbreaks were reported in UK in week 52, three in primary schools, seven in prisons and two in care homes. This brings the total reported this season so far to 135. It should be noted that most schools across the UK were on holiday in week 52.
One-hundred and fourteen of 161 (70.8%) specimens from patients with ILI presenting to sentinel GPs in England in week 52, were reported as positive for influenza. The proportion of specimens reported to DataMart (England) as positive for influenza was 41.4% (2,047 of 4,941). The proportion of samples positive for RSV increased slightly and for rhinovirus continued to decrease.
Currently the main circulating influenza strains are influenza A (H1N1) and influenza B.
From week 36, 50 deaths associated with influenza infection have been reported. The majority of fatal cases reported were unimmunised.
By week 52, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 70.0%. For those in a risk group aged under 65 it was 45.4%.
In Europe several countries are starting to report influenza activity, primarily associated with influenza A H1N1 (2009). In the USA and Canada overall influenza activity has increased, associated primarily with influenza A (H3N2) and B viruses.

...

Of 4,941 respiratory specimens reported to the English Data Mart virological surveillance system as taken in week 52, 2,047 (41.4%, slightly decreased from 46.2% in week 51) were positive for influenza (1,576 H1N1 (2009), 87 influenza A not subtyped and 384 influenza B) (figure 7). The highest age-specific positivity rate for H1N1 2009 decreased from 43.6% to 37.9% in 15-44 year olds, and for influenza B it increased from 30.7% to 32.2% in 5-14 year olds. The proportion positive for respiratory syncytial virus (RSV) increased slightly from 10.1% to 11.1% and for rhinovirus is decreased from 3.5% to 1.3%.
Of the 161 samples submitted via the two English GP-based sentinel schemes in week 52, 114 (70.8%) were positive for influenza (79 influenza H1N1 2009) and 35 influenza B) (Table 1). By age group, the highest proportion positive was in adults aged 15-44 years at 75.6%. In children aged 5-14 years, the proportion positive decreased from 76.3% to 58.3% (figure 8). In week 52, 26 specimens were reported as positive for influenza (22 A unknown subtype, one A (H3) and 3 influenza B) through the sentinel GP scheme in
Scotland, and two specimens were reported positive for influenza H1N1 (2009) in Northern Ireland (table 1).

...

Of 636 influenza H1N1 (2009) viruses reported as tested for antiviral susceptibility at RVU and regional labs since week 40 2010, six have been found to carry the H275Y mutation which confers resistance to the
antiviral drug oseltamivir. Fifty-one H1N1 (2009) viruses, three influenza A H3 viruses and fifty-seven influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

...

HPA is receiving reports of fatal influenza cases from various sources (clinicians, laboratory reports and death certificates) across the United Kingdom. These reports have been reconciled and verified by clinicians. These cases will not represent all influenza-related deaths. Up to 5 January 2011, 50 fatal cases have been verified by HPA as related to influenza infection. Of these cases, 45 have been associated with H1N1 (2009) infection and five with influenza B infection.
The deaths have been mainly in younger adults and children, with five cases less than 5 years of age; eight cases from 5 to 14 years; 33 cases from 15 to 64 years and four cases older than 64 years. Thirty-three of 48 fatal cases with available information (69%) were in one of the CMO-defined clinical risk groups for vaccination. The leading reported clinical risk factors were underlying neurological disease (n=11) and respiratory disease including asthma (n=13). Of cases with available information on immunisation history, 36 of 39 cases had not received 2010/11 trivalent influenza vaccine more than two weeks before illness onset. Thirty-three of 34 cases had not received monovalent pandemic influenza vaccination last season.
In week 50, an estimated 10,880 all-cause deaths were registered in England and Wales (source: Office for National Statistics). This is decreased from 11,193 in week 49 but remains just above the upper limit of expected levels for this time of year (figure 9). Potential factors for this excess include recent cold weather and circulating respiratory viruses.

http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1287148330414

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 1

Week 2 http://www.hpa.org.uk/web/HPAwebFile.../1294739353955 report is out;

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 2: 112 fatalities confirmed

HPA Weekly National Influenza Report
Summary of UK surveillance of influenza and other seasonal respiratory
illnesses
12 January 2011 ? Week 2

Summary
GP and school closures over the Christmas/New Year period will have affected surveillance indicators so all data should be interpreted with caution. Indeed, several influenza indicators have apparently plateaued. GP
consultation rates remain above baseline levels in all four countries. 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 overall well matched to the current influenza vaccine.
In week 1 (ending 9 January), the weekly influenza/influenza-like illness (ILI) consultation rates increased in England (108.4 per 100,000), Scotland (55.8 per 100,000), Wales (92.8 per 100,000) and Northern Ireland (274.4 per 100,000).
The weekly national proportions of NHS Direct calls for cold/flu and fever have decreased in week 1.
Eleven acute respiratory disease outbreaks were reported in UK in week 1, three in care homes, two in hospitals, five in prisons and one in a primary school. This brings the total reported this season so far to 146.
Seventy-six of 156 (48.7%) specimens from patients with ILI presenting to sentinel GPs in England in week 1, were reported as positive for influenza. The proportion of specimens reported to DataMart (England) as positive for influenza decreased to 27.8% (1,104 of 3,968). The proportion of samples
positive for RSV decreased slightly and was low for rhinovirus, parainfluenza, adenovirus and HMPV.
Currently the main circulating influenza strains are influenza A (H1N1) and influenza B.
From week 36, 112 deaths associated with influenza infection have been reported.By week 1, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 70.8%. For those in a risk group aged under 65 it was 46.3%.
In Europe, several countries are continuing to report increasing influenza activity, primarily associated with influenza A H1N1 (2009). In the USA influenza activity has decreased slightly but continued to increased in Canada. In North America influenza A (H3N2) and B viruses have been predominant.

...

Of 3,968 respiratory specimens reported to the English Data Mart virological surveillance system as taken in week 1, 1,104 (27.8%, decreased from 44.0%in week 52) were positive for influenza (772 H1N1 (2009), 52 influenza A not subtyped and 280 influenza B) (figure 7). The positivity rates decreased in most age groups. The highest age-specific positivity rate for H1N1 2009 was 21.2% in 0-5 year olds. In the 15-44 year group it decreased from 38.3% to 20.4%. For influenza B it was decreased from 34.4% to 17.9% in 5-14 year olds. The proportion positive for respiratory syncytial virus (RSV) decreased slightly from 10.1% to 9% and remained low for rhinovirus, HMPV, parainfluenza and adenovirus.
Of the 156 samples submitted via the two English GP-based sentinel schemes in week 1, 76 (48.7%) were positive for influenza (43 influenza H1N1 (2009), two A non-subtyped and 31 influenza B) (Table 1). The proportion positive decreased in all age groups with the highest proportion positive in adults aged 15-44 years at 50.7% (decreased from 72.5%) (figure 8). The proportion of samples positive for influenza through GP sentinel surveillance in Northern Ireland, Scotland and Wales also decreased in week 1 (table 1).

...

Of 811 influenza H1N1 (2009) viruses reported as tested for antiviral susceptibility at RVU and regional labs since week 40 2010, 17 (comment: an increase of 11 from last week)have been found to carry the H275Y mutation which confers resistance to the antiviral drug oseltamivir. Fifty-one H1N1 (2009) viruses have been fully tested for susceptibility, one of which was found to be phenotypically resistant to oseltamivir (including in the 17 reported above), while all
51 retained sensitivity to zanamivir. Three influenza A H3 viruses and fifty-eight influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

...

Up to 12 January 2011, 112 fatal cases from across the UK have been reported to the HPA and confirmed to be associated with influenza infection. Ninety-five of these cases were associated with H1N1 (2009) infection, five with influenza B infection and 12 as yet untyped influenza infection. The deaths have been mainly in younger adults and children. Among the 101 cases with information on age: six (6%) have been less than 5 years; nine (9%) from 5 to 14 years; 70 (69%) from 15 to 64 years and 16 (16%) older than 64 years.
Sixty-three of 81 fatal cases with available information (78%) were in one of the CMO-defined clinical risk groups for vaccination. The leading reported clinical risk factors for those with information were underlying neurological disease (n=14/37; 38%) and respiratory disease including asthma
(n=17/42; 40%). Of cases with available information on immunisation history, 40 of 47 (85%) cases had not received 2010/11 trivalent influenza vaccine this season. Thirty-three of 35 cases with available information had not received monovalent pandemic influenza vaccination last season.In week 51, an estimated 11,484 all-cause deaths were registered in England and Wales (source: Office for National Statistics). This is increased from 10,880 in week 50 and remains above the upper limit of expected levels for this time of year (figure 9). Potential factors for this excess include
recent cold weather and circulating respiratory viruses.

...

http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1294739353955

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 2: 112 fatalities confirmed

HPA Weekly National Influenza Report
Summary of UK surveillance of influenza and other seasonal respiratory
illnesses
20 January 2011 ? Week 3

Summary
Influenza activity appears to be declining in the UK. GP consultation rates remain above baseline levels in England, Wales and Northern Ireland. 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 overall well matched to the current influenza vaccine.
In week 2 (ending 16 January), the weekly influenza/influenza-like illness (ILI) consultation rates decreased in England (66.5 per 100,000), Scotland (42.9 per 100,000), Wales (51.5 per 100,000) and Northern Ireland (194.0 per 100,000).The weekly national proportions of NHS Direct calls for cold/flu have decreased, although a slight increase in calls for fever in children has been observed.
Seven acute respiratory disease outbreaks were reported in the UK in week 2, two in care homes, one in a hospital, one in a prison and three in schools. This brings the total reported this season so far to 153.
Seventy-nine of 278 (28.4%) specimens from patients with ILI presenting to sentinel GPs in England in
week 2, were reported as positive for influenza. The proportion of specimens reported to DataMart (England) as positive for influenza decreased to 19.7% (584 of 2,961). The proportion of samples positive for RSV was stable and was low for rhinovirus, parainfluenza, adenovirus and HMPV.
Currently the main circulating influenza strains are influenza A (H1N1) and influenza B.
Since week 36, 254 UK deaths associated with influenza infection have been reported. Excess all-cause mortality continues to be observed in week 1.By week 2, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 71.7%. For those in a risk group aged under 65 years it was 48.0%. Amongst frontline health-care workers the provisional uptake was 26.1% by 31 December 2010.
In Europe, most countries are continuing to report increasing influenza activity, primarily associated with influenza A H1N1 (2009). In the USA influenza activity has decreased slightly but continued to increase
in Canada. In North America influenza A (H3N2) and B viruses have been predominant.

...

Of 2,961 respiratory specimens reported to the English Data Mart virological surveillance system as taken in week 2, 584 (19.7%, decreased from 28.9% in week 1) were positive for influenza (354 H1N1 (2009), 35 influenza A not subtyped and 195 influenza B) (figure 7). The positivity rates decreased in most age groups. The greatest decrease in positivity for H1N1 2009 was in the 15-44 year group, from 20.6% to 12.3%. For influenza B the positivity rate increased from 18.8% to 25% in the 5-14 year age group, while it decreased in all other groups. The proportion positive for respiratory syncytial virus (RSV) was stable at 9.6% and remained
low for rhinovirus, HMPV, parainfluenza and adenovirus.
Of the 278 samples submitted via the two English GP-based sentinel schemes in week 2, 79 (28.4%) were positive for influenza (34 influenza H1N1 (2009) and 37 influenza B) (Table 1). The proportion positive decreased in all age groups except in the under 5 year group, which increased from 21.4% to 44.4% (figure 8). The proportion of samples positive for influenza through GP sentinel surveillance in Northern Ireland and Wales also decreased in week 2 but increased in Scotland (table 1).

...

Of 1,001 influenza H1N1 (2009) viruses reported as tested for antiviral susceptibility at RVU and regional labs since week 40 2010, 27 (an increase of 10 from last week)have been found to carry the H275Y mutation which confers resistance to the
antiviral drug oseltamivir. Fifty-one H1N1 (2009) viruses have been fully tested for susceptibility, one of which was found to be phenotypically resistant to oseltamivir (including in the 27 reported above), while all
51 retained sensitivity to zanamivir. Three influenza A H3 viruses and fifty-eight influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

...

Up to 19 January 2011, 254 fatal influenza cases from across the UK have been reported to the HPA, including 165 cases from England. Further epidemiological information on cases is available on 214 of these cases. One hundred and ninety-five (91%) of these 214 cases were associated with H1N1 (2009) infection, three with untyped influenza A and 16 (7%) with influenza B infection. Reported deaths have been mainly in younger adults and children. Amongst the 210 cases with information on age: seven (3%) have been less than 5 years; 11 (5%) from 5 to 14 years; 137 (65%) from 15 to 64 years and 55 (26%) older than 64 years of age. One hundred and twenty-eight of 159 fatal cases with available information (81%) were in one of the CMO-defined clinical risk groups for vaccination. The leading reported clinical risk factors for those with information were underlying respiratory disease including asthma (n=29) and neurological disease (n=15).
Of cases with available information on immunisation history, 59 of 71 (83%) cases had not received the 2010/11 trivalent influenza vaccine this season. Thirty-eight of 40 cases with available information had not received the monovalent pandemic influenza vaccine last season.

In week 1, an estimated 12,644 all-cause deaths were registered in England and Wales (source: Office for National Statistics). This is increased from 11,484 in week 51 and remains above the upper limit of expected levels for this time of year (figure 9). Potential factors for this excess include
recent cold weather and circulating respiratory viruses. It should be noted that closures of registry offices in the Christmas/New Year period results in a dip and subsequent increase in death registrations.


...

http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1294740008526

[JimO]

Re: HPA Weekly National Influenza Report Weeks 49 - 3: 254 fatalities confirmed

Up to 19 January 2011, 254 fatal influenza cases from across the UK have been reported to the HPA,
including 165 cases from England. Further epidemiological information on cases is available on 214 of these
cases. One hundred and ninety-five (91%) of these 214 cases were associated with H1N1 (2009) infection,
three with untyped influenza A and 16 (7%) with influenza B infection. Reported deaths have been mainly in
younger adults and children. Amongst the 210 cases with information on age: seven (3%) have been less
than 5 years; 11 (5%) from 5 to 14 years; 137 (65%) from 15 to 64 years and 55 (26%) older than 64 years of
age. One hundred and twenty-eight of 159 fatal cases with available information (81%) were in one of the
CMO-defined clinical risk groups for vaccination. The leading reported clinical risk factors for those with
information were underlying respiratory disease including asthma (n=29) and neurological disease (n=15).

Comment: Notice that there have been 55 deaths reported in the age group >64 years and this is nearly four times the number of Influenza B deaths (N=16). That suggests that at least 38 people over 64 died from pH1N1, which is ~15% of the reported deaths. So, unlike last season, the older population does not appear to have the same immunity exhibited with the variant circulating in 2009-10.

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 3: 254 fatalities confirmed

HPA Weekly National Influenza Report
Summary of UK surveillance of influenza and other seasonal respiratory illnesses
27 January 2011 ? Week 4

Summary
Influenza activity is declining in the UK. GP consultation rates remain above baseline levels in England, Wales and Northern Ireland. The predominant influenza virus is now influenza B; influenza A H1N1 (2009) continues to be detected, with very few, sporadic influenza A (H3N2) virus detections. The H1N1 (2009) virus strain is virologically and epidemiologically similar to that seen during the pandemic. The virus strains circulating are overall well matched to the current influenza vaccine.
In week 3 (ending 23 January) the weekly ILI consultation rate decreased England (40.7 per 100,000), Wales (26.9 per 100,000) and Northern Ireland (126.2 per 100,000), while a slight increase was observed in Scotland (47.9 per 100,000)
The weekly national proportions of NHS Direct calls for cold/flu and fever have decreased.
Twelve acute respiratory disease outbreaks were reported in the UK in week 3, two in care homes, two in prisons and eight in schools. This brings the total reported this season so far to 165.
Twenty-eight of 186 (15.1%) specimens from patients with ILI presenting to sentinel GPs in England in week 3, were reported as positive for influenza. The proportion of specimens reported to DataMart (England) as positive for influenza decreased to 13.5% (267 of 1,942). The proportion of samples
positive for RSV and rhinovirus increased and was low for parainfluenza, adenovirus and HMPV.
Since week 36, 338 UK deaths associated with influenza infection have been reported. Excess all-cause mortality continues to be observed in week 2.By week 3, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 72.2%. For those in a risk group aged under 65 years it was 49.1%. Amongst frontline health-care workers the provisional uptake was 26.1% by 31 December 2010.
In Europe, most countries are reporting regional or widespread influenza activity, with medium to very high influenza-like illness/acute respiratory infection (ILI/ARI) consultation rates and increasing trends, primarily associated with influenza A H1N1 (2009). In North America, influenza activity has decreased; influenza A (H3N2) and B viruses continue to be predominant.

...

Of 1,942 respiratory specimens reported to the English Data Mart virological surveillance system as taken in week 3, 267 (13.5%, decreased from 20.5% in week 2) were positive for influenza (121 H1N1 (2009), 12 influenza A not subtyped and 134 influenza B) (figure 7). The positivity rates for H1N1 (2009) decreased in all age groups, with the highest proportion now in the 5-14 year age group at 7.8%. For influenza B the overall positivity rate remained stable at 10.1% and increased slightly in some age groups. The highest proportion positive was in the 5-14 year age group, increasing from 24.6% to 30%. The proportion positive for respiratory syncytial virus (RSV) was increased slightly to 10.8%; the highest positivity rate for RSV is in the under 5 year group at 30.9% but the greatest increase was in the 5-14 year group (from 4.1% to 14.8%). An increase in positivity was seen for rhinovirus (from 3.9% to 9%)
while rates remained low for HMPV, parainfluenza and adenovirus.

Of the 186 samples submitted via the two English GP-based sentinel schemes in week 3, 28 (15.1%) were positive for influenza (6 influenza H1N1 (2009), one influenza A (H3) and 18 influenza B) (Table 1). The proportion positive decreased in all age groups (figure 8). The proportion of samples positive for influenza through GP sentinel surveillance in Northern Ireland and Scotland remained high (table 1).

...

Of 1,038 influenza H1N1 (2009) viruses reported as tested for antiviral susceptibility at RVU and regional labs since week 40 2010, 39 have been found to carry the H275Y mutation which confers resistance to the
antiviral drug oseltamivir (That's 11/37 this week -Ro). Sixty-four H1N1 (2009) viruses have been fully tested for susceptibility, one of which was found to be phenotypically resistant to oseltamivir (including in the 39 reported above), while all 64 retained sensitivity to zanamivir. Three influenza A H3 viruses and 100 influenza B viruses have been fully tested for susceptibility and found to be sensitive to oseltamivir and zanamivir.

There have been reports of secondary bacterial infections amongst influenza cases. Analysis of surveillance data has identified increases for a number of invasive bacterial pathogens in December 2010 compared to December 2009. This includes invasive S. pneumoniae (19% increase; 736 compared to 619 isolates confirmed by the HPA national reference laboratory. The increase in cases is confined to the 15-64 age group; with 391 compared to 234 isolates in the two periods) and Group A Streptococcus (61% increase; 166 compared to 103 isolates confirmed by the HPA national reference laboratory). Increases have continued in January 2011, with a total of 136 GAS isolates received by the HPA National reference laboratory to date
compared to 97 for the whole month of January 2010. For meningococcal disease, 344 cases have been confirmed by the HPA Meningococcal Reference Unit in the period 1st December 2010 to 21st Jan 2011.
This number is higher than the equivalent period in 2009/2010 (165 cases), but similar to the number in 2008/2009 (336 cases).

...

Up to 26 January 2011, 338 fatal influenza cases from across the UK have been reported to the HPA, including 237 cases from England. Two hundred and seventy-three (92%) of 297 cases with available information were associated with H1N1 (2009) infection, four with untyped influenza A and 19 (6%) with influenza B infection. Reported deaths have been mainly in younger adults and children. Amongst the 306 cases with information on age: ten (3%) have been less than 5 years; 14 (5%) from 5 to 14 years; 217 (71%) from 15 to 64 years and 65 (21%) older than 64 years of age. One hundred and eighty-four of 252 fatal cases with available information (73%) were in one of the CMO-defined clinical risk groups for vaccination.
The leading reported clinical risk factors for those with information were underlying respiratory disease including asthma (n=49) and immunosuppression (n=43).
Of cases with available information on immunisation history, 82 of 108 (76%) cases had not received the 2010/11 trivalent influenza vaccine this season. Thirty-nine of 41 (95%) of cases with available information had not received the monovalent pandemic influenza vaccine last season. (Why information only for such a tiny fraction? -Ro)

In week 2, an estimated 13,133 all-cause deaths were registered in England and Wales (source: Office for National Statistics). This is increased from 12,644 death registrations in week 1 and remains above the upper limit of expected levels for this time of year (figure 9). Potential factors for this
excess include recent cold weather and circulating respiratory viruses. It should be noted that closures of registry offices in the Christmas/New Year period results in a dip and subsequent increase in death registrations.

http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1294740643915

[Vibrant62]

Re: HPA Weekly National Influenza Report Weeks 49 - 4: 338 fatalities confirmed

There is no valid reason of which I am aware as to why so little data should be available on vaccine status this year or last RoRo
.
Also of note is the fact that H274Y incidence is at 3.8%, so the rise seen last week to @4% is showing consistency (2% prior to this).

This is of concern, especially if the incidence continues to rise. In 2009 H274Y went from 2% to 100% in a single year.

[Ronan Kelly]

Re: HPA Weekly National Influenza Report Weeks 49 - 4: 338 fatalities confirmed

With regards to H274Y this week added 11 cases and 37 samples last week was 10 from 190 and the week before 11 from 175 - altogether 32 from 402 or about 8% of recent samples.

[JimO]

Re: HPA Weekly National Influenza Report Weeks 49 - 3: 254 fatalities confirmed

Since week 36, 338 UK deaths associated with influenza infection have been reported. Excess all-cause mortality continues to be observed in week 2... By week 3, the proportion of people in England aged over 65 years who had received the 2010/11 influenza vaccine was 72.2%...

Two hundred and seventy-three (92%) of 297 cases with available information were associated with H1N1 (2009) infection, four with untyped influenza A and 19 (6%) with influenza B infection. Reported deaths have been mainly in younger adults and children. Amongst the 306 cases with information on age: ten (3%) have been less than 5 years; 14 (5%) from 5 to 14 years; 217 (71%) from 15 to 64 years and 65 (21%) older than 64 years of age.

The data this week suggests two things:

1) The pH1N1 is showing signs of escaping the vaccine; and
2) The virus has mutated such that it has escaped the immunity experienced by the older population during last season.

The reason I say this is that if we assume that all Influenza B deaths are elderly, then at least 46 people 65 and older died from H1N1, despite that age group having a very high rate of vaccination (72%).

[JJackson]

Re: HPA Weekly National Influenza Report Weeks 49 - 4: 338 fatalities confirmed

With regards to H274Y this week added 11 cases and 37 samples last week was 10 from 190 and the week before 11 from 175 - altogether 32 from 402 or about 8% of recent samples.

The ongoing problem is the failure to separate out the H274Y in wild type virus and that which is generated in a hospital setting after prolonged anti-viral usage. Thankfully most of the strains promoted in hospitalised patients are at a genetic disadvantage when they have to compete with their community 'wild type' relatives and will die out. The problem is we can not see how many are not succumbing to the competition and as Vibrant pointed out the old seasonal H1N1 made the transition from susceptible to resistant in short order. One of the few 'silver linings' in the H1N1(2009) pandemic was its displacement of the old resistant H1N1 with a susceptible one. It is important to maintain this window as long as possible until we can get replacement anti-virals to market, it is difficult to know how successful we are being if the data is collected and reported in a way that does not clarify the position.