Preparing for the next flu pandemic
More cases of H5N1 infection in<SUP> </SUP>humans increase the chances that the virus will adapt towards<SUP> </SUP>efficient transmission between humans and therefore of a flu<SUP> </SUP>pandemic.<SUP> </SUP>
<SUP></SUP>
The United Kingdom is well advanced in its preparations<SUP> </SUP>for a flu pandemic.<SUP>2</SUP> The British Infection Society, British<SUP> </SUP>Thoracic Society, Health Protection Agency, and Department of<SUP> </SUP>Health have recently developed and published provisional guidelines<SUP> </SUP>on the clinical management of pandemic flu.<SUP>3</SUP>
These guidelines<SUP> </SUP>cover the clinical management of children and adults with flu<SUP> </SUP>during a pandemic.<SUP> </SUP>
<SUP></SUP>
In interpandemic years when influenza is circulating<SUP> </SUP>in the community, presentation with acute fever and new (or<SUP> </SUP>in chronic lung disease, worsening) cough is highly predictive<SUP> </SUP>of flu in adults.<SUP>4</SUP>
In a pandemic, key predictive features may<SUP> </SUP>change as a result of altered thresholds for consultation, symptom<SUP> </SUP>presentation, and clinical features. If this occurs, an updated<SUP> </SUP>clinical definition will be released by the Health Protection<SUP> </SUP>Agency, informed by guidance from the World Health Organization.<SUP> </SUP>
<SUP></SUP>
Randomised controlled trials, cohort studies,<SUP> </SUP>and modelling studies show that antiviral agents, if given promptly,<SUP> </SUP>can reduce the length of illness, viral secretions, and complications;<SUP> </SUP>these agents may also reduce peak clinical attack rates.<SUP>5</SUP> <SUP></SUP><SUP>6</SUP> The UK government has stockpiled enough oseltamivir<SUP> </SUP>for 25% of the population to be treated; if the clinical attack<SUP> </SUP>rate is higher then antivirals will have to be prioritised to<SUP> </SUP>risk groups.<SUP> </SUP>
<SUP></SUP>
Previous pandemics have shown that secondary<SUP> </SUP>bacterial complications (particularly pneumonia) have a high<SUP> </SUP>morbidity and mortality.<SUP>7</SUP> <SUP>8</SUP> <SUP></SUP><SUP>9</SUP> Antibiotic treatment for Streptococcus pneumoniae, Staphylococcus<SUP> </SUP>aureus, and Haemophilus influenzae should be considered at first<SUP> </SUP>consultation for adults who have serious worsening of symptoms<SUP> </SUP>or fever that does not start to subside after 48 hours, and<SUP> </SUP>for patients with chronic obstructive pulmonary disease or other<SUP> </SUP>severe comorbid disease (or both).
Doxycycline or co-amoxiclav<SUP> </SUP>are recommended<SUP>3</SUP> in the community and in patients in hospital<SUP> </SUP>who are not severely ill.<SUP> </SUP>
<SUP></SUP>
Patients referred to hospital are likely to<SUP> </SUP>require management of worsening comorbid disease, such as cardiac<SUP> </SUP>failure or flu related pneumonia. Bilateral x ray changes in<SUP> </SUP>flu related pneumonia raise the possibility of primary viral<SUP> </SUP>pneumonia, which has a poor prognosis and should be treated<SUP> </SUP>as severe pneumonia.<SUP>3</SUP> I
ndications for transfer to critical care<SUP> </SUP>are no different in a pandemic, although limited resources will<SUP> </SUP>require effective triage and difficult ethical decisions.<SUP> </SUP>
<SUP></SUP>
In children, as in adults, fever, cough, and<SUP> </SUP>rhinorrhoea are cardinal symptoms of flu, but infants may simply<SUP> </SUP>be febrile and non-specifically unwell. Children should be given<SUP> </SUP>fluids, antipyretics (avoid aspirin), and antivirals?oseltamivir<SUP> </SUP>in liquid form can be prescribed for children aged 1-7 years.<SUP>3</SUP><SUP> </SUP>Infants under 1 year are a particular problem.
They have a higher<SUP> </SUP>risk of hospital admission and secondary bacterial infection,<SUP>10</SUP><SUP> </SUP>and oseltamivir is not indicated on the basis of central nervous<SUP> </SUP>system toxicity and mortality in infant rats, which is assumed<SUP> </SUP>to reflect immaturity of the blood-brain barrier. Infants therefore<SUP> </SUP>need to be assessed by a doctor, and the threshold for antibiotic<SUP> </SUP>treatment should be low. Those with underlying cardiac or respiratory<SUP> </SUP>disease, the immunocompromised, and the non-ambulant are also<SUP> </SUP>at increased risk of complications and should receive early<SUP> </SUP>antibiotics. Co-amoxiclav is recommended for children under<SUP> </SUP>12 years.<SUP>3</SUP><SUP> </SUP>
<SUP></SUP>
These clinical guideline recommendations are<SUP> </SUP>informed by data from seasonal flu and previous pandemics.<SUP>3</SUP><SUP> </SUP>As with all pandemic plans, uncertainties are acknowledged.<SUP> </SUP>In particular, the virus strain and its disease potential in<SUP> </SUP>terms of clinical spectrum of illness, spread, and severity<SUP> </SUP>of illness are unknown. Furthermore, the susceptibility profile<SUP> </SUP>to current antiviral agents cannot be guaranteed, as discussed<SUP> </SUP>by Tsiodras and colleagues in this week's BMJ.<SUP>11</SUP> Other uncertainties<SUP> </SUP>relate to the epidemiology of pathogens that may have a role<SUP> </SUP>in secondary infections.
Flu related pneumonia occurs in up<SUP> </SUP>to a fifth of cases; these cases are often associated with Staphylococcus<SUP> </SUP>aureus and have a worse outcome.<SUP>12</SUP> <SUP>13</SUP> Community<SUP> </SUP>acquired strains of methicillin resistant Staphylococcus aureus<SUP> </SUP>(MRSA) are currently relatively uncommon in Europe and the UK,<SUP> </SUP>but are of increasing concern in the United States.<SUP>14</SUP> A change<SUP> </SUP>in the epidemiology of this infection in Europe could have important<SUP> </SUP>consequences in the event of a flu pandemic.<SUP> </SUP>
<SUP></SUP>
These guidelines will need to be revised in<SUP> </SUP>accordance with updated clinical and epidemiological data. Currently<SUP> </SUP>the pandemic alert status stands at phase 3 (human infection<SUP> </SUP>with a new flu virus subtype but no, or limited, human to human<SUP> </SUP>spread). If WHO raises the pandemic alert status to phase 5,<SUP> </SUP>the last of the three pre-pandemic phases (large cluster(s)<SUP> </SUP>of human cases and virus better adapted to humans), the guidelines<SUP> </SUP>will be updated.<SUP> </SUP>
<SUP></SUP>
In the meantime these guidelines will help to<SUP> </SUP>plan stockpiling of essential resources, coordination of services,<SUP> </SUP>and standardisation of care. They also provide the framework<SUP> </SUP>for national, regional, and local operational guidelines that<SUP> </SUP>take account of and detail the actions needed in the face of<SUP> </SUP>limited resources.<SUP> </SUP>
<SUP></SUP>
<SUP></SUP>
Wei Shen Lim, consultant respiratory physician (weishen.lim@nuh.nhs.uk)<SUP>1</SUP>, Anne Thomson, consultant in paediatric respiratory medicine<SUP>2</SUP>, Paul Little, professor of primary care research<SUP>3</SUP>
<SUP>1</SUP> Nottingham University Hospitals, Nottingham NG5 1PB, <SUP>2</SUP> John Radcliffe Hospital Oxford, Oxford OX3 9DU, <SUP>3</SUP> University of Southampton, Southampton SO17 1BJ
<HR align=left width="30%" noShade SIZE=1>
References
<DL><DT>Bird flu and transparency </DT><DD>Fiona Godlee
BMJ 2007 334: 0. <NOBR>[Extract] [Full Text] </NOBR>
</DD></DL><DL><DT>The next best thing </DT><DD>Douglas Kamerow
BMJ 2007 334: 0. <NOBR>[Extract] [Full Text] </NOBR>
</DD></DL><DL><DT>Role of combination antiviral therapy in pandemic influenza and stockpiling implications </DT><DD>Sotirios Tsiodras, John D Mooney, and Angelos Hatzakis
BMJ 2007 334: 293-294. <NOBR>[Extract] [Full Text] </NOBR></DD></DL>
BMJ 2007;334:268-269 (10 February), doi:10.1136/bmj.39101.628715.80
New clinical guidelines focus on coordinating services and standardising<SUP> </SUP>care
In the past three years, the incidence of infection<SUP> </SUP>with the H5N1 variant of avian flu has increased in humans in<SUP> </SUP>southeast Asia during periods corresponding to winter and spring<SUP> </SUP>in the northern hemisphere.<SUP>1</SUP> New clinical guidelines focus on coordinating services and standardising<SUP> </SUP>care
More cases of H5N1 infection in<SUP> </SUP>humans increase the chances that the virus will adapt towards<SUP> </SUP>efficient transmission between humans and therefore of a flu<SUP> </SUP>pandemic.<SUP> </SUP>
<SUP></SUP>
The United Kingdom is well advanced in its preparations<SUP> </SUP>for a flu pandemic.<SUP>2</SUP> The British Infection Society, British<SUP> </SUP>Thoracic Society, Health Protection Agency, and Department of<SUP> </SUP>Health have recently developed and published provisional guidelines<SUP> </SUP>on the clinical management of pandemic flu.<SUP>3</SUP>
These guidelines<SUP> </SUP>cover the clinical management of children and adults with flu<SUP> </SUP>during a pandemic.<SUP> </SUP>
<SUP></SUP>
In interpandemic years when influenza is circulating<SUP> </SUP>in the community, presentation with acute fever and new (or<SUP> </SUP>in chronic lung disease, worsening) cough is highly predictive<SUP> </SUP>of flu in adults.<SUP>4</SUP>
In a pandemic, key predictive features may<SUP> </SUP>change as a result of altered thresholds for consultation, symptom<SUP> </SUP>presentation, and clinical features. If this occurs, an updated<SUP> </SUP>clinical definition will be released by the Health Protection<SUP> </SUP>Agency, informed by guidance from the World Health Organization.<SUP> </SUP>
<SUP></SUP>
Randomised controlled trials, cohort studies,<SUP> </SUP>and modelling studies show that antiviral agents, if given promptly,<SUP> </SUP>can reduce the length of illness, viral secretions, and complications;<SUP> </SUP>these agents may also reduce peak clinical attack rates.<SUP>5</SUP> <SUP></SUP><SUP>6</SUP> The UK government has stockpiled enough oseltamivir<SUP> </SUP>for 25% of the population to be treated; if the clinical attack<SUP> </SUP>rate is higher then antivirals will have to be prioritised to<SUP> </SUP>risk groups.<SUP> </SUP>
<SUP></SUP>
Previous pandemics have shown that secondary<SUP> </SUP>bacterial complications (particularly pneumonia) have a high<SUP> </SUP>morbidity and mortality.<SUP>7</SUP> <SUP>8</SUP> <SUP></SUP><SUP>9</SUP> Antibiotic treatment for Streptococcus pneumoniae, Staphylococcus<SUP> </SUP>aureus, and Haemophilus influenzae should be considered at first<SUP> </SUP>consultation for adults who have serious worsening of symptoms<SUP> </SUP>or fever that does not start to subside after 48 hours, and<SUP> </SUP>for patients with chronic obstructive pulmonary disease or other<SUP> </SUP>severe comorbid disease (or both).
Doxycycline or co-amoxiclav<SUP> </SUP>are recommended<SUP>3</SUP> in the community and in patients in hospital<SUP> </SUP>who are not severely ill.<SUP> </SUP>
<SUP></SUP>
Patients referred to hospital are likely to<SUP> </SUP>require management of worsening comorbid disease, such as cardiac<SUP> </SUP>failure or flu related pneumonia. Bilateral x ray changes in<SUP> </SUP>flu related pneumonia raise the possibility of primary viral<SUP> </SUP>pneumonia, which has a poor prognosis and should be treated<SUP> </SUP>as severe pneumonia.<SUP>3</SUP> I
ndications for transfer to critical care<SUP> </SUP>are no different in a pandemic, although limited resources will<SUP> </SUP>require effective triage and difficult ethical decisions.<SUP> </SUP>
<SUP></SUP>
In children, as in adults, fever, cough, and<SUP> </SUP>rhinorrhoea are cardinal symptoms of flu, but infants may simply<SUP> </SUP>be febrile and non-specifically unwell. Children should be given<SUP> </SUP>fluids, antipyretics (avoid aspirin), and antivirals?oseltamivir<SUP> </SUP>in liquid form can be prescribed for children aged 1-7 years.<SUP>3</SUP><SUP> </SUP>Infants under 1 year are a particular problem.
They have a higher<SUP> </SUP>risk of hospital admission and secondary bacterial infection,<SUP>10</SUP><SUP> </SUP>and oseltamivir is not indicated on the basis of central nervous<SUP> </SUP>system toxicity and mortality in infant rats, which is assumed<SUP> </SUP>to reflect immaturity of the blood-brain barrier. Infants therefore<SUP> </SUP>need to be assessed by a doctor, and the threshold for antibiotic<SUP> </SUP>treatment should be low. Those with underlying cardiac or respiratory<SUP> </SUP>disease, the immunocompromised, and the non-ambulant are also<SUP> </SUP>at increased risk of complications and should receive early<SUP> </SUP>antibiotics. Co-amoxiclav is recommended for children under<SUP> </SUP>12 years.<SUP>3</SUP><SUP> </SUP>
<SUP></SUP>
These clinical guideline recommendations are<SUP> </SUP>informed by data from seasonal flu and previous pandemics.<SUP>3</SUP><SUP> </SUP>As with all pandemic plans, uncertainties are acknowledged.<SUP> </SUP>In particular, the virus strain and its disease potential in<SUP> </SUP>terms of clinical spectrum of illness, spread, and severity<SUP> </SUP>of illness are unknown. Furthermore, the susceptibility profile<SUP> </SUP>to current antiviral agents cannot be guaranteed, as discussed<SUP> </SUP>by Tsiodras and colleagues in this week's BMJ.<SUP>11</SUP> Other uncertainties<SUP> </SUP>relate to the epidemiology of pathogens that may have a role<SUP> </SUP>in secondary infections.
Flu related pneumonia occurs in up<SUP> </SUP>to a fifth of cases; these cases are often associated with Staphylococcus<SUP> </SUP>aureus and have a worse outcome.<SUP>12</SUP> <SUP>13</SUP> Community<SUP> </SUP>acquired strains of methicillin resistant Staphylococcus aureus<SUP> </SUP>(MRSA) are currently relatively uncommon in Europe and the UK,<SUP> </SUP>but are of increasing concern in the United States.<SUP>14</SUP> A change<SUP> </SUP>in the epidemiology of this infection in Europe could have important<SUP> </SUP>consequences in the event of a flu pandemic.<SUP> </SUP>
<SUP></SUP>
These guidelines will need to be revised in<SUP> </SUP>accordance with updated clinical and epidemiological data. Currently<SUP> </SUP>the pandemic alert status stands at phase 3 (human infection<SUP> </SUP>with a new flu virus subtype but no, or limited, human to human<SUP> </SUP>spread). If WHO raises the pandemic alert status to phase 5,<SUP> </SUP>the last of the three pre-pandemic phases (large cluster(s)<SUP> </SUP>of human cases and virus better adapted to humans), the guidelines<SUP> </SUP>will be updated.<SUP> </SUP>
<SUP></SUP>
In the meantime these guidelines will help to<SUP> </SUP>plan stockpiling of essential resources, coordination of services,<SUP> </SUP>and standardisation of care. They also provide the framework<SUP> </SUP>for national, regional, and local operational guidelines that<SUP> </SUP>take account of and detail the actions needed in the face of<SUP> </SUP>limited resources.<SUP> </SUP>
<SUP></SUP>
<SUP></SUP>
Wei Shen Lim, consultant respiratory physician (weishen.lim@nuh.nhs.uk)<SUP>1</SUP>, Anne Thomson, consultant in paediatric respiratory medicine<SUP>2</SUP>, Paul Little, professor of primary care research<SUP>3</SUP>
<SUP>1</SUP> Nottingham University Hospitals, Nottingham NG5 1PB, <SUP>2</SUP> John Radcliffe Hospital Oxford, Oxford OX3 9DU, <SUP>3</SUP> University of Southampton, Southampton SO17 1BJ
<HR align=left width="30%" noShade SIZE=1>
<!-- null -->Competing interests: None<SUP> </SUP>declared.<SUP> </SUP>
<!-- null -->Provenance and peer review:<SUP> </SUP>Non-commissioned, not externally peer reviewed.<SUP> </SUP>References
- <!-- null -->
- <SUP></SUP>Epidemiology of WHO-confirmed human cases of avian influenza A(H5N1) infection. Wkly Epidemiol Rec 2006;81:249-57.<!-- HIGHWIRE ID="334:7588:268:1" -->[Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Mounier-Jack S, Coker RJ. How prepared is Europe for pandemic influenza? Analysis of national plans. Lancet 2006;367:1405-11.<!-- HIGHWIRE ID="334:7588:268:2" -->[CrossRef][ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Provisional guidelines from the British Infection Society, British Thoracic Society and Health Protection Agency in collaboration with the Department of Health. Pandemic flu: the clinical management of patients with an influenza-like illness during an influenza pandemic . Thorax J Infect <!-- HIGHWIRE ID="334:7588:268:3" --><!-- /HIGHWIRE --><SUP></SUP><!-- null -->
- <SUP></SUP>Call SA, Vollenweider MA, Hornung CA, Simel DL, McKinney WP. Does this patient have influenza? JAMA 2005;293:987-97.<!-- HIGHWIRE ID="334:7588:268:4" --><NOBR>[Abstract/Free Full Text]</NOBR><!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Ferguson NM, Cummings DA, Fraser C, Cajka JC, Cooley PC, Burke DS. Strategies for mitigating an influenza pandemic. Nature 2006;442:448-52.<!-- HIGHWIRE ID="334:7588:268:5" -->[CrossRef][ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Kaiser L, Wat C, Mills T, Mahoney P, Ward P, Hayden F. Impact of oseltamivir treatment on influenza-related lower respiratory tract complications and hospitalizations. Arch Intern Med 2003;163:1667-72.<!-- HIGHWIRE ID="334:7588:268:6" --><NOBR>[Abstract/Free Full Text]</NOBR><!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Anon. Some aspects of the recent epidemic of influenza in Dundee. BMJ 1958;1:908-13.<!-- HIGHWIRE ID="334:7588:268:7" -->[ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Abrahams A, Hallows N, French H. Influenzo-pneumococcal and influenzo-streptococcal septicaemia: epidemic influenzal "pneumonia" of highly fatal type and its relation to "purulent bronchitis". Lancet 1919;1:1-11.<!-- HIGHWIRE ID="334:7588:268:8" --><!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Schwarzmann SW, Adler JL, Sullivan RJ Jr, Marine WM. Bacterial pneumonia during the Hong Kong influenza epidemic of 1968-1969. Arch Intern Med 1971;127:1037-41.<!-- HIGHWIRE ID="334:7588:268:9" -->[CrossRef][ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Neuzil KM, Zhu Y, Griffin MR, Edwards KM, Thompson JM, Tollefson SJ, et al. Burden of interpandemic influenza in children younger than 5 years: a 25-year prospective study. J Infect Dis 2002;185:147-52.<!-- HIGHWIRE ID="334:7588:268:10" -->[CrossRef][ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Tsiodras S, Mooney J, Hatzakis A. The role of combined antiviral therapy in pandemic influenza. BMJ 2007 doi: 10.1136/bmj.39105.428981.BE<!-- HIGHWIRE ID="334:7588:268:11" --><NOBR>[Free Full Text]</NOBR><!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Oswald NC, Shooter RA, Curwen MP. Pneumonia complicating Asian influenza. BMJ 1958;2:1305-11.<!-- HIGHWIRE ID="334:7588:268:12" -->[ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Robertson L, Caley JP, Moore J. Importance of Staphylococcus aureus in pneumonia in the 1957 epidemic of influenza A. Lancet 1958;2:233-6.<!-- HIGHWIRE ID="334:7588:268:13" -->[ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP><!-- null -->
- <SUP></SUP>Hageman JC, Uyeki TM, Francis JS, Jernigan DB, Wheeler JG, Bridges CB, et al. Severe community-acquired pneumonia due to Staphylococcus aureus, 2003-4 influenza season. Emerg Infect Dis 2006;12:894-9.<!-- HIGHWIRE ID="334:7588:268:14" -->[ISI][Medline]<!-- /HIGHWIRE --><SUP> </SUP>
<DL><DT>Bird flu and transparency </DT><DD>Fiona Godlee
BMJ 2007 334: 0. <NOBR>[Extract] [Full Text] </NOBR>
</DD></DL><DL><DT>The next best thing </DT><DD>Douglas Kamerow
BMJ 2007 334: 0. <NOBR>[Extract] [Full Text] </NOBR>
</DD></DL><DL><DT>Role of combination antiviral therapy in pandemic influenza and stockpiling implications </DT><DD>Sotirios Tsiodras, John D Mooney, and Angelos Hatzakis
BMJ 2007 334: 293-294. <NOBR>[Extract] [Full Text] </NOBR></DD></DL>