Flu Update – Week 09, 2015

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Influenza activity in Ireland remained elevated in community and hospital settings during the week ending 1st March 2015 (week 9 2015), with some indicators of influenza activity decreasing.

The sentinel GP influenza-like illness (ILI) consultation rate was 53.4 per 100,000 population in week 9 2015, a decrease compared to the updated rate of 60.0 per 100,000 population during week 8 2015.  ILI rates have remained above the Irish baseline threshold (21.0/100,000 population) for eight consecutive weeks. ILI rates were highest in 5-14 year olds during week 9 2015.  The proportion of influenza–related calls to GP Out-of-Hours services decreased during week 9 2015.

Influenza positivity remained elevated during week 9 2015. Influenza A(H3) is the predominant circulating influenza virus this season. Respiratory syncytial virus (RSV) positivity has continued to decrease since the peak of activity during the last two weeks in December.  The latest complete data on respiratory admissions reported from a network of sentinel hospitals were elevated. 86 confirmed influenza hospitalised cases were notified to HPSC during the week ending 1st March 2015, a decrease from 116 cases reported during the previous week. The median age of confirmed influenza hospitalised cases to date this season is 58 years.  Fifteen influenza-associated deaths have been reported to HPSC this season, with a median age of 81 years.

Ten acute respiratory general outbreaks were reported to HPSC during the week ending 1st March 2015: five of these outbreaks were associated with influenza and five acute respiratory outbreaks had no pathogens identified. The majority of confirmed influenza outbreaks this season have been associated with influenza A(H3) in residential care facilities for the elderly.

In Europe, increased influenza activity has continued, in particular in western and central European countries.  The number and percentage of influenza virus detections in sentinel specimens showed a slight reduction in what might be described as a high plateau phase of the influenza season.

Flu Update – Week 08, 2015

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Influenza activity in Ireland remained elevated in community and hospital settings during the week ending 22nd February 2015 (week 8 2015). 

 The sentinel GP influenza-like illness (ILI) consultation rate was 59.5 per 100,000 population in week 8 2015, a decrease compared to the updated rate of 70.4 per 100,000 population during week 7 2015.  ILI rates have remained above the Irish baseline threshold (21.0/100,000 population) for seven consecutive weeks. ILI rates were highest in 5-14 and 15-64 year olds during week 8 2015.  The proportion of influenza–related calls to GP Out-of-Hours services remained elevated during week 8 2015.

Influenza positivity remained high during week 8 2015, with 179 (35.7%) influenza positive specimens reported from the NVRL: 136 A(H3), 13 A(H1)pdm09, 12 A (not subtyped) and 18 B. Influenza A(H3) is the predominant circulating influenza virus this season.  11 associated with A(H3), two with A(H1)pdm09, 11 with A (not subtyped) and three with B.  Fifteen influenza-associated deaths have been reported to HPSC this season, with a median age of 81 years. Twelve acute respiratory general outbreaks were reported to HPSC during the week ending 22nd February 2015: eight of these outbreaks were associated with influenza and four acute respiratory outbreaks had no pathogens identified.

The majority of confirmed influenza outbreaks this season have been associated with influenza A(H3) in residential care facilities for the elderly. In Europe, influenza activity continued, in particular in western and central European countries. The overall proportion of influenza positive specimens and the total number of sentinel influenza virus detections decreased slightly which may be indicative of several countries having passed the peak of influenza activity.

Flu Update – Week 07, 2015

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Influenza activity in Ireland increased in community and hospital settings during the week ending 15th February 2015 (week 7 2015). 

The sentinel GP influenza-like illness (ILI) consultation rate was 67.5 per 100,000 population in week 7 2015, a significant increase compared to the updated rate of 36.9 per 100,000 population during week 6 2015.  ILI rates have remained above the Irish baseline threshold (21.0/100,000 population) for six consecutive weeks. ILI rates increased in 5-14 and 15-64 year olds and in those aged 65 years or older during week 7 2015.  The proportion of influenza–related calls to GP Out-of-Hours services remained elevated during week 7 2015.

Influenza positivity increased during week 7 2015, with 162 (31.0%) influenza positive specimens reported from the NVRL: 117 A(H3), 19 A(H1)pdm09, 12 A (not subtyped) and 14 B. Influenza A(H3) is the predominant circulating influenza virus this season. Respiratory syncytial virus (RSV) positivity has continued to decrease since the peak of activity during the last two weeks in December.  The latest complete data on respiratory admissions reported from a network of sentinel hospitals were elevated. 58 confirmed influenza hospitalised cases were notified to HPSC during the week ending 15th February 2015, an increase compared to the previous week.

Ten influenza-associated deaths have been reported to HPSC this season, with a median age of 83 years. Sixteen acute respiratory general outbreaks were reported to HPSC during the week ending 15th February 2015: 12 of these outbreaks were associated with influenza, one outbreak was associated with human metapneumovirus (hMPV) and three acute respiratory outbreaks had no pathogens identified. The majority of confirmed influenza outbreaks this season have been associated with influenza A(H3) in residential care facilities for the elderly. Globally, influenza activity remained high in the northern hemisphere with influenza A(H3N2) viruses predominating this season.

Flu Update – Week 04, 2015

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Influenza activity in Ireland is slowly increasing; with an increase in influenza positivity and confirmed influenza outbreaks reported during week 4 2015.

The sentinel GP influenza-like illness (ILI) consultation rate was 31.3 per 100,000 population in week 4 2015, remaining low, and stable compared to the updated rate of 30.4 per 100,000 population during week 3 2015. ILI rates remained above the Irish baseline threshold (21.0 per 100,000 population). ILI rates increased in the 0-4 and 5-14 year age groups during week 4 2015.  The proportion of influenza–related calls to GP Out-of-Hours services increased slightly during week 4 2015.

Influenza positivity increased during week 4 2015, with 81 (23.5%) influenza positive specimens reported from the NVRL: 73 A(H3), 1 A(H1)pdm09, 4 A (not subtyped) and 3 B. Influenza A(H3) is the predominant circulating influenza virus this season. Respiratory syncytial virus (RSV) positivity has decreased significantly in recent weeks. Respiratory admissions:  The latest complete data on respiratory admissions reported from a network of sentinel hospitals were elevated. 18 confirmed influenza hospitalised cases were notified to HPSC during the week ending January 25th 2015: 15 associated with influenza A(H3), one with influenza A(H1)pdm09 and two with influenza A (not subtyped).  Six influenza A-associated deaths have been reported to HPSC this season, five associated with influenza A(H3) and one with influenza A (not subtyped). Eight acute respiratory outbreaks were reported to HPSC during the week ending January 25th 2015: six associated with influenza A(H3), one with RSV and one with no pathogen identified.

The majority of confirmed influenza outbreaks this season have been associated with influenza A(H3) in community hospitals/residential care facilities for the elderly. Globally, influenza activity was high in the northern hemisphere with influenza A(H3N2) viruses predominating this season. Antigenic characterisation of most recent A(H3N2) viruses this season indicated differences from the A(H3N2) virus used in the influenza vaccines for the northern hemisphere 2014/2015. As a consequence of the mismatch between vaccine and circulating strains, reduced vaccine effectiveness is expected. Vaccination of the elderly and other risk groups is still recommended, as the A(H3N2) component is expected to reduce the likelihood of severe outcomes due to cross-protection, and both the A(H1N1)pdm09 and influenza B components are expected to be effective.

Flu Update – Week 03, 2015

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Influenza activity stabilised in Ireland during week 3 2015, remaining at relatively low levels.   

 The sentinel GP influenza-like illness (ILI) consultation rate was 30.4 per 100,000 population in week 3 2015, remaining low, and stable compared to the updated rate of 30.1 per 100,000 population during week 2 2015.  ILI rates remained above the Irish baseline threshold (21.0 per 100,000 population). ILI rates increased in the 0-4 and 5-14 year age groups during week 3 2015.  The proportion of influenza–related calls to GP Out-of-Hours services decreased slightly during week 3 2015.

Influenza positivity decreased slightly during week 3 2015, with 36 (13.2%) influenza positive specimens reported from the NVRL: 28 A(H3), 1 A(H1)pdm09, 4 A (not subtyped) and 3 B. Influenza A(H3) has been the predominant circulating influenza virus this season.  Four influenza A(H3)-associated deaths have been reported to HPSC this season. Two acute respiratory outbreaks were reported to HPSC during the week ending January 18th 2015: one associated with influenza A(H3) and one with no pathogen identified.

Globally, influenza activity continued to increase in the northern hemisphere with influenza A(H3N2) viruses predominating this season. Antigenic characterisation of most recent A(H3N2) viruses this season indicated differences from the A(H3N2) virus used in the influenza vaccines for the northern hemisphere 2014/2015. Vaccination remains the most effective means of preventing infection by seasonal influenza viruses.

Flu Update – Week 02, 2015

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Influenza-like illness GP consultation rates increased above baseline levels for the first time this season, during week 2 2015.   

Influenza activity remained at low levels in Ireland during week 2 2015; however most indicators of influenza activity are increasing. The sentinel GP influenza-like illness (ILI) consultation rate was 29.0 per 100,000 population in week 2 2015, remaining low, however increasing above baseline levels for the first time this season. ILI rates are above the Irish baseline threshold (21.0 per 100,000 population). ILI rates increased in the 5-14 and 15-64 year age groups during week 2 2015.

The proportion of influenza–related calls to GP Out-of-Hours services remained stable during week 2 2015. Influenza positivity increased during week 2 2015, with 48 influenza positive specimens reported from the NVRL: 45 influenza A(H3), 1 A(H1)pdm09 and 2 influenza A (not subtyped). 15 confirmed influenza hospitalised cases were notified to HPSC during the week ending January 10th 2015: 12 associated with influenza A(H3) and three associated with influenza A (not subtyped). To date this season, two confirmed influenza cases were admitted to critical care and reported to HPSC, one associated with influenza A(H3) and one associated with influenza A(H1)pdm09. Three influenza A(H3)-associated deaths have been reported to HPSC this season.

Eight acute respiratory outbreaks were reported to HPSC during the week ending January 10th 2015: four associated with influenza A, two with RSV, and two with unknown pathogens.  Globally, influenza activity continued to increase in the northern hemisphere with influenza A(H3N2) viruses predominating so far this season.

Flu Update – Week 01, 2015

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Most indicators of influenza activity in Ireland increased during week 1 2015, however remained at low levels.  

The sentinel GP influenza-like illness (ILI) consultation rate was 15.2 per 100,000 population in week 1 2015, remaining low, however increasing compared to the rate of 7.6 per 100,000 reported during week 52 2014. ILI rates remain below the Irish baseline threshold (21.0 per 100,000 population). ILI rates remain at low levels in all age groups, however increased slightly in the 15-64 year age group and those aged 65 years or older.  The proportion of influenza–related calls to GP Out-of-Hours services increased significantly during week 1 2015.

Influenza positivity remained stable during weeks 52 2014 and 1 2015, with 18 influenza positive specimens reported from the NVRL: 17 influenza A(H3) and 1 influenza A (not subtyped). Respiratory syncytial virus (RSV) positivity decreased during week 1 2015, however remained at elevated levels, as expected at this time of year.  Positive detections of human metapneumovirus (hMPV) have increased in recent weeks.  The latest complete data on respiratory admissions reported from a network of sentinel hospitals were elevated, as expected at this time of year.  Three confirmed influenza hospitalised cases were notified to HPSC during week 52 2014 (week ending 28th December 2014) and week 1 2015 (week ending January 4th 2015). One confirmed influenza A(H3)-associated death was reported to HPSC. No acute respiratory outbreaks were reported to HPSC during week 52 2014 (week ending 28th December 2014) and week 1 2015 (week ending January 4th 2015).

Globally, influenza activity has continued to increase in the northern hemisphere, with influenza A(H3N2) viruses predominating this season to date. While there have been difficulties in characterising A(H3N2) viruses antigenically in Europe, as in the United States of America, the majority of the A(H3N2) viruses characterised genetically have fallen into genetic subgroups containing viruses that have drifted antigenically compared to the virus recommended for use in the 2014/2015 northern hemisphere influenza vaccine. Although this may compromise the effectiveness of the A(H3N2) component of the vaccine, it is still important that people are vaccinated, particularly those at risk of developing severe influenza symptoms. Vaccination remains the most effective means of preventing infection by seasonal influenza viruses.

Flu Update – Week 51, 2014

Update by Dr J Gallagher, Employment Health Advisors (EHA):

Influenza activity in Ireland remained at low levels during week 51 2014.

The sentinel GP influenza-like illness (ILI) consultation rate was 11.8 per 100,000 population in week 51 2014, remaining low, and decreasing slightly compared to the updated rate of 14.6 per 100,000 reported during week 50 2014. ILI rates remain below the Irish baseline threshold (21.0 per 100,000 population). ILI rates remain at low levels in all age groups.  The proportion of influenza–related calls to GP Out-of-Hours services remained stable and at low levels during week 51 2014. Influenza positivity increased slightly during week 51 2014, with 12 (4.8%) influenza positive specimens reported from the NVRL: 11 influenza A(H3) and 1 influenza B.

There were no reports of any influenza-associated deaths during week 51 2014.  Two acute respiratory outbreaks were reported to HPSC during week 51 2014, one associated with influenza A(H3) in HSE-NE  and one associated with an unidentified pathogen in HSE-W. Both were in residential care facilities/community hospitals/long stay units. Overall influenza activity in the European Region remained low, however increased during week 50 2014. Influenza A(H3N2) viruses have predominated in Europe for the season to date. The genetic characteristics of A(H3N2) viruses indicate that in Europe, as in the United States of America, there may be significant differences between circulating A(H3N2) viruses and the virus used in the influenza vaccine.  Although this may affect the effectiveness of the A(H3N2) component of the vaccine, the current influenza vaccine is likely to provide protection against infection by other currently circulating influenza viruses. Vaccination is the most effective means of preventing infection by seasonal influenza viruses, and it is still important that people are vaccinated.  The benefits of vaccination are considerable in protecting the elderly and those in risk groups, even if vaccine effectiveness against one of the circulating viruses may turn out to be low.

Flu Update – Week 49, 2014

Update by Dr J Gallagher, Employment Health Advisors (EHA):

All indicators of influenza activity in Ireland were at low levels during week 49 2014.

Respiratory syncytial virus (RSV) positivity remained at high levels during week 49 2014, as expected at this time of year. The sentinel GP influenza-like illness (ILI) consultation rate was 8.5 per 100,000 population in week 49 2014, remaining low, and stable compared to the updated rate of 8.4 per 100,000 reported during week 48 2014. ILI rates remain below the Irish baseline threshold (21.0 per 100,000 population). ILI rates remain at low levels in all age groups. The proportion of influenza–related calls to GP Out-of-Hours services increased slightly during week 49 2014, however remained at low levels.

No confirmed influenza positive specimens were reported from sentinel GP or non-sentinel sources during week 49 2014. There were no reports of any influenza-associated deaths during week 49 2014.  No acute respiratory outbreaks were reported to HPSC during week 49 2014. Overall influenza activity in the European Region remained low, with some countries reporting increasing trends for ILI consultations.

Flu Update – Week 48, 2014

Update by Dr J Gallagher, Employment Health Advisors (EHA):

All indicators of influenza activity in Ireland were at low levels during week 48 2014.

Respiratory syncytial virus (RSV) positivity remained at high levels during week 48 2014, as expected at this time of year.  The sentinel GP influenza-like illness (ILI) consultation rate was 8.4 per 100,000 population in week 48 2014, remaining low, and stable compared to the updated rate of 5.7 per 100,000 reported during week 47 2014. ILI rates remain below the Irish baseline threshold (21.0 per 100,000 population). ILI rates remain at low levels in all age groups. The proportion of influenza–related calls to GP Out-of-Hours services remained at low levels during week 48 2014.

One confirmed influenza A(H3) positive specimen was reported from sentinel GP sources during week 48 2014. No confirmed influenza positive specimens were reported from non-sentinel sources during week 48 2014. No confirmed influenza hospitalised cases were notified to HPSC during week 48 2014. No confirmed influenza cases admitted to ICU were reported to HPSC this season.  There were no reports of any influenza-associated deaths during week 48 2014.  No acute respiratory outbreaks were reported to HPSC during week 48 2014. Overall influenza activity in the European Region remained low, with some countries reporting increasing trends for ILI consultations.