Increase in influenza-like illness

Published:

During week 9 2014 (week ending March 2nd), the general practitioner consultation rate for influenza-like illness (ILI) in Ireland increased to 53.6 per 100,000 population from an updated rate of 50.5 per 100,000 during week 8 (week ending February 23rd). This rate exceeds the Irish baseline threshold of 21 per 100,000 for the fifth consecutive week (used to assess influenza activity during the 2013/2014 influenza season in Ireland). The rate of increase during week 9 was most pronounced in the 5-14 year age group. Influenza A(H3) is the predominant virus in circulation with influenza A(H1)pdm09 co-circulating. The flu report for week 9 is available here.

Due to the levels of influenza activity reported 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

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 2013 (Chapter 11). 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 and bronchopulmonary dysplasia), chronic heart disease, diabetes mellitus, chronic liver disease, chronic renal disease, chronic neurological disease (including multiple sclerosis hereditary and degenerative disorders of the central nervous system), haemoglobinopathies.
    • those with immunosuppression due to disease or treatment including those with missing or non functioning spleens
  • Those with any condition (e.g. spinal cord injury, seizure disorder, or other neuromuscular disorder) that can compromise respiratory function especially those attending special schools/day centres
  • Those with Down syndrome
  • Children with moderate or severe neurodevelopmental disorders such as cerebral palsy and intellectual disability.
  • Children 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. Because influenza virus vaccine is not a live vaccine, it is very safe in pregnancy.
  • Healthcare workers both for their own protection and for the protection of patients who may have a suboptimal response to influenza vaccinations.
  • Residents of nursing homes, and other long stay institutions
  • Carers
  • Household contacts of at-risk persons
  • 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.