Increase in influenza-like illness

Published:

During week 50 2012 (week ending December 16th), the general practitioner consultation rate for influenza-like illness (ILI) in Ireland increased to 24.9 per 100,000 population from a rate of 11.3 per 100,000 during week 49 (week ending December 9th). This rate exceeds the Irish baseline threshold of 21/100,000 (used to assess influenza activity during the 2012/2013 influenza season in Ireland) above which the use of antiviral drugs for defined risk groups is activated. The rate of increase was most pronounced in the 5-14 year age group. To date this season, influenza B has been the dominant influenza virus detected. The flu report for week 50 is available here.

Due to the levels of influenza activity seen last week in Ireland, antiviral drugs for the treatment and/or prevention of influenza in at-risk patients are recommended in line with the Interim guidelines on the use of antivirals for the treatment and prophylaxis of influenza which are available here.

The defined risk groups for antivirals are:

a) Persons aged 65 years and over

b) Children aged < 2 years

c) Those with chronic respiratory disease including people on medication for asthma

d) Those with chronic heart, kidney, liver or neurological disease

e) Those with Diabetes Mellitus

f) Those with Haemoglobinopathies

g) Those with immunosuppression (whether due to treatment or disease)

h) Pregnancy (including up to two weeks post partum)

i) Morbid obesity (BMI ≥40)

j) Children with any condition (e.g. cognitive dysfunction, spinal cord injury, seizure disorder or other NM disorder) that can compromise respiratory function, especially those attending special schools/day centres

See algorithms for the management of influenza when it is circulating in the community

  • The Interim Algorithm for the Emergency Department Management of Adults who may have influenza is available here
  • The Interim Algorithm for the Emergency Department Management of Children who may have influenza is available here
  • The Interim Algorithm for the Primary Care Management of persons with influenza is available here

Pregnancy
Guidelines on the use of antivirals in pregnancy for patients with influenza are available here

Residential Care facilities
Guidelines and a checklist for the prevention, detection and control of influenza-like illness and influenza outbreaks in residential care facilities are available here

Infection Control Advice is available here

Influenza Vaccine
As influenza-like illness rates are increasing and both influenza A and B are circulating, it is also important that persons in at-risk groups for influenza are vaccinated as these groups are at higher risk of developing complications from influenza.

Risk groups for influenza vaccine are outlined below as per the Immunisation Guidelines for Ireland 2008 (Chapter 7-updated in August 2012). They are as follows:

  • All those aged 50 years and older[1]
  • Adults and children over 6 months of age with any of the following:
    • chronic illness requiring regular follow up (e.g. chronic respiratory disease including cystic fibrosis, moderate or severe asthma, chronic heart disease, diabetes mellitus, chronic liver disease, chronic neurological disease including multiple sclerosis hereditary and degenerative disorders of the central nervous system)
    • those who are immunosuppressed due to disease or treatment including those with missing or non functioning spleens
  • Children with any condition (e.g. cognitive dysfunction, spinal cord injury, seizure disorder, or other neuromuscular disorder) that can compromise respiratory function especially those attending special schools/day centres
  • Children and teenagers on longā€term aspirin therapy (because of the risk of Reyes syndrome)
  • Those with morbid obesity i.e. Body Mass Index ≥ 40
  • All pregnant women. The vaccine can be given at any stage of pregnancy. This year influenza vaccine is not recommended for those women up to six weeks post partum
  • Healthcare workers
  • Residents of nursing homes, and other long stay institutions
  • Carers
  • People who have close, regular contact with pigs, poultry or water fowl

Details of Influenza Activity in Ireland are available on the HPSC website at: http://www.hpsc.ie/hpsc/A-Z/Respiratory/Influenza/SeasonalInfluenza/Surveillance/
See also: http://www.hpsc.ie/hpsc/A-Z/Respiratory/Influenza/SeasonalInfluenza/

Details of Influenza Information for Health Professionals on the HPSC website at:
http://www.hpsc.ie/hpsc/A-Z/Respiratory/Influenza/SeasonalInfluenza/Guidance/

Details of Influenza Activity in Europe are available on the ECDC website here

Details of international influenza websites are available at:
http://www.hpsc.ie/hpsc/A-Z/Respiratory/Influenza/SeasonalInfluenza/Links/

[1] The National Immunisation Advisory Committee has recommended the influenza vaccine for all those aged 50 years and older. The HSE has agreed to implement this for all those aged 65 years and older.