Human H1N1 and Seasonal Influenza



Human H1N1 (2009 Pandemic) and Seasonal Influenza

Last updated 4th January 2011. Whilst there is no current pandemic, the information and resources are retained below for reference. This page will be updated as necessary in the future.

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At the beginning of January 2011 influenza activity is rising steadily across the UK. There are a large proportion of severe cases, particularly in children, younger adults and pregnant women, with a disproportionate use of critical care and the consequent effects on bed availability. Influenza A H1N1 (2009) and B are the predominant circulating viruses with a few A (H3N2) viruses.  The H1N1 (2009) virus strain is virologically and epidemiologically similar to that seen during last year’s pandemic.  The virus strains circulating are overall well matched to the current influenza vaccine, but increased influenza activity is expected well into the New Year.

This website page has been prepared by the College of Emergency Medicine to assist Emergency Departments in dealing with current levels of influenza, and its effects on emergency services. It is divided into two sections: principles and resources. This page will be reviewed, and if necessary updated, on a regular basis. If you have any questions or comments these should be sent to Phil McMillan at the College: Philip.McMillan@collemergencymed.ac.uk

Principles

1. Every Emergency Department should have a nominated lead to coordinate the influenza response whilst remaining up to date with official guidance.

2. It is essential to work with commissioners and healthcare partners to ensure a co-ordinated response. The ED must be strongly represented on local flu working groups and committees.

3. The College of Emergency Medicine recommends that Emergency Departments do NOT prescribe or dispense antiviral drugs to patients who do not require hospital admission. The role of Emergency Departments, and acute hospitals in general, is to continue to provide the core emergency service whilst also treating those flu patients who require hospital admission. This preserves vital emergency capacity for those patients who need it most.

4. The DH “swine flu clinical package” was replaced on 26th October 2009 (see resource 5 below). It is important to emphasise that “these tools and pathways are for use only when high healthcare demand leads to the need for strict hospital admission triage in affected areas”. In other words, the clinical package should only be applied, by agreement across a healthcare community, in a severe and exceptional situation.

5. Current guidance would suggest that the following groups are likely to be at significant risk of complications:

  • Pregnant women
  • Children under 5 years, and particularly those under 1 year
  • Children with neurodevelopmental delay
  • Immunocompromised patients
  • Patients with significant obesity or asthma

6. Antiviral therapy is most effective within 48 hours of symptom onset, and probably has limited value after this time.

7. The Department of Health has identified the following priority groups for vaccination:

  • Individuals aged six months and up to 65 years in the current seasonal flu vaccine clinical at-risk groups
  • All pregnant women, subject to licensing considerations on trimesters
  • Household contacts of immunocompromised individuals
  • People aged 65 and over in the current seasonal flu vaccine clinical at-risk groups

8. Swine flu should be considered in all adults and children being admitted to hospital with any respiratory illness, in order to avoid overlooking cases that will then lead to widespread transmission on the wards. The Royal College of Paediatricians and Child Health recommends that while influenza activity is above seasonal threshold, all sick children being admitted or considered for admission to hospital with influenza like illness or its complications can be considered for prompt initiation of oseltamivir and concurrent broad spectrum antibiotics. Children in the recognised co-morbid risk groups OR with severe disease (HDU/PICU admissions) should start oseltamivir without delay. Antiviral therapy can be stopped if proven to be influenza negative by appropriate investigations, i.e. PCR negative nasal swabs/NPA PLUS PCR negative ETA/BAL if ventilated. In addition, infants admitted with bronchiolitis may have one or more respiratory viruses including H1N1-2009. A positive near-patient RSV test does not exclude other respiratory pathogens and clinicians should have a low threshold for starting oseltamivir and antibiotics if there are atypical features, severe or progressive disease.

Resources

1. The College has prepared a document outlining the lessons learnt from the 2009 H1N1 pandemic. This is available here: Pandemic Flu 2009: Lessons learned by UK EDs

2. The latest guidance for healthcare professionals, including a weekly update, is available from the Health Protection Agency (HPA): http://www.hpa.org.uk/.../SeasonalInfluenza/GuidanceForHealthProfessionals/

3. 2010/2011 treatment guidelines for patients with influenza are available at: http://www.dh.gov.uk/.../DH_122682

4. In addition, the latest guidance on the pharmacological treatment and prophylaxis of influenza from the HPA can be found at: http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1287147812045

5. The swine flu clinical package for use only in a severe and exceptional situation (see principle 4 above) can be accessed at: http://www.dh.gov.uk/.../DH_106495

6. Department of Heath clinical guidelines for pregnancy (prepared with the Royal College of Obstetricians and Gynaecologists) were released on 30th October 2009 and updated on 30th December 2009. These are available at: http://www.dh.gov.uk/en/.../DH_107770

7. Useful information from the Royal College of Paediatrics and Child Health, including guidance for specialist areas of paediatric practice, can be found at: http://www.rcpch.ac.uk/Policy/H1N1Influenza

8. Guidance on prescribing Oseltamivir for children under 1 year of age is given at: http://www.rcpch.ac.uk/doc.aspx?id_Resource=6934

9. DH guidance outlining when it may be appropriate to offer antivirals after exposure to swine flu can be found at: http://www.dh.gov.uk/en/.../DH_107133

10. Advice on managing demand and capacity in healthcare organisations can be found at:
http://www.dh.gov.uk/en/.../DH_098769

11. Information for patients can be found on the NHS Choices website: http://www.nhs.uk/conditions/pandemic-flu/Pages/Introduction.aspx

12. Video clips demonstrating procedures for handwashing and mask fitting have been provided by Addenbrooke's Hospital (with thanks to Sue Robinson).

Handwashing video clip: available as .avi file or .rv file

Mask Fitting video clip: available as .avi file or .rv file. Also, a Mask fitting leaflet is available here.

(The .avi files may require you to download a codec to view in Windows Media Player, click on 'Web Help' if prompted. The .rv files can be viewed with RealPlayer).

Professor Jonathan Benger.
Chair, Clinical Effectiveness Committee.