Flu Update – Week 04, 2015

January 29, 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.

EurFlu


Flu Update – Week 03, 2015

January 23, 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.

EurFlu


Flu Update – Week 02, 2015

January 15, 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.

EurFlu


Flu Update – Week 01, 2015

January 9, 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.

EurFlu


Flu Update – Week 51, 2014

January 5, 2015

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.

EurFlu


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