Choose either a specific country's guidelines or the WHO’s guidelines regarding reporting infectious disease. Apply these requirements to a specific outbreak situation. What role would health sy

EMHJ   •  Vol. 17 No. 4  •  2011 Eastern Mediterranean Health JournalLa Revue de Santé de la Méditerranée  orientale 342 Clinical guidelines Clinical management guidelines for pandemic (H1N1) 2009 virus infection in the Eastern Mediterranean Region: technical basis and overview S. Al Hajjar, 1 M.R. Malik, 2 Z. Hallaj, 2 H. El-Bushra, 2 M. Opoka 2 and A.R. Mafi 2 ABSTRACT During the spring of 2009, a novel influenza A (H1N1) virus of swine origin caused human infection and acute respiratory illness in Mexico. After initially spreading in North America, the virus spread globally resulting in the first influenza pandemic since 1968. While the majority of illnesses caused by pandemic (H1N1) 2009 were mild and self-limiting, severe complications, including fatalities, were also reported. In view of the increasing number of laboratory-confirmed cases and deaths from pandemic (H1N1) 2009 in the Eastern Mediterranean Region of the World Health Organization, the Regional Office convened a consultation meeting of experts involved in the clinical management of patients infected with pandemic (H1N1) 2009 virus. The consultation resulted in developing an interim guidance and algorithm for clinical management of pandemic (H1N1) 2009 virus infection in health-care settings. This paper describes the process, the technical basis and the components of this interim guidance. 1Infectious Diseases Section, Department of Paediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia. 2Communicable Disease Surveillance and Response Unit, Division of Communicable Diseases, World Health Organization Regional Office for the Eastern Mediterranean, Cairo, Egypt (Correspondence to M.R. Malik: [email protected]).

Received: 15/12/10; accepted: 09/03/11 سويرف ةحئالج يريسرلا يربدتلل ةيداشرلإا لئلادلا (H1N1 ) 2009 ةماعلا ةرظنلاو ينقتلا ساسلأا :طسوتلما قشر ميلقإ في فيام اضيرلع ،اكوبوأ نترام ،ى َ شر ُ بلا نسح ،جلاح يرهز ،كلام نحمرلا نومأم ،راجلحا يماس .كيسكلما في داح سيفنت للاتعاب مهتباصإو شربلا ىودع لىإ ريزنلخا نم هردصمو ديدلجا A (H1N1 سويرف ىدأ ، 2009 عيبر للاخ :ةـصلالخا ةيبلاغ نأ عمو . 1968 ماع ذنم ازنولفنأ ةحئاج لوأ روهظ لىإ ى ّ دأو ، ً ايلماع هراشتنا حبصأ ام ناعسر ،اكيرمأ لماش في ليولأا سويرفلا راشتنا دعبو ةدايزل ً ارظنو .تايفولا اهيف ماب ةميخو تافعاضم ً اضيأ تلجس انهأ لاإ ، ً ايتاذ ةدودمحو ةفيفخ تناك H1N1) 2009 سويرف نع ةجمانلا تلالاتعلاا عماتجلا يميلقلإا بتكلما اعد ،ةيلماعلا ةحصلا ةمظنلم طسوتلما قشر ميلقإ في ً ايبرتمخ ةدكؤلماو H1N1) 2009 نع ةجمانلا تايفولاو تلاالحا دادعأ يربدتلل ةيمزراوخو تقؤم يداشرإ ليلد دع ُ أ ةرواشملل ةجيتنو .ةحئالجا سويرفب ينباصلما ضىرملل يريسرلا يربدتلاب ين ّ ينعلما ءابرخلل يراشتسا ليلدلا تان ّ وكمو ،ينقتلا ساسلأاو ،ةيلمعلا كلت ثحبلا اذه فصيو .ةيحصلا ةياعرلا عقاوم في H1N1) 2009 ةحئاج سويرفب ىودعلل يريسرلا .تقؤلما Lignes directrices pour la prise en charge clinique de l'infection par l\ e virus de la grippe pandémique (H1N1) 2009 dans la Région de la Méditerranée orientale : données techniques initiales et présentation générale RéSuMé Au cours du printemps de l'année 2009 au Mexique, un nouveau virus grippal A (H1N1) d'origine porcine a été la cause d'infections et de pathologies respiratoires aiguës chez l'homme. Après s'être d'abord propagé en Amérique du Nord, le virus s'est étendu mondialement pour devenir la première pandémie grippale depuis 1968. Alors que la majorité des pathologies causées par la grippe pandémique (H1N1) 2009 était modérée et à guérison spontanée, des complications graves, y compris des décès, ont également été signalés. Compte tenu du nombre croissant d'infections et de décès par le virus de la grippe pandémique (H1N1) 2009 confirmés en laboratoire dans la Région OMS de la Méditerranée orientale, le Bureau régional a convoqué une réunion consultative d'experts impliqués dans la prise en charge clinique de patients infectés par ce virus. La consultation a permis d'élaborer des lignes directrices temporaires et un algorithme pour la prise en charge clinique de l'infection par le virus de la grippe pandémique (H1N1) 2009 en milieu de soins. Le présent article décrit le processus, les données techniques et les composantes de ces lignes di\ rectrices temporaires. طسوتلما قشرل ةيحصلا ةلجلما شرع عباسلا دلجلما عبارلا ددعلا 343 Background At the  beginning  of April  2009,  hu - man infections  with  a  novel  strain  of  influenza  A  (H1N1)  virus  emerged  in   Mexico  [1].  After  initially  spreading  among  persons  in  the  United  States,  Mexico  and  Canada,  the  virus  spread  globally,  resulting  in the  first  influenza   pandemic since 1968 [2,3].  As of  6  August  2010,  worldwide  more  than 214 countries  and over - seas territories  or  communities  have  reported  laboratory-confirmed  cases  o f  p a n d e m i c  ( H 1 N 1 )  2 0 0 9  v i r u s  infection,  and  there  have  been  around  18 500 deaths [4]. Kuwait  and the United  Arab Emir - ates were  the  first  2  countries  in  the  World  Health  Organization  Eastern   Mediterranean  Region (WHO-EMR)   reporting confirmed  cases of pandemic  (H1N1)  2009  on  25  May  2009.  Up  to  6  August  2010, all 22  countries  had  reported  laboratory-confirmed  cases  of  infection,  and 1019  deaths  had been  recorded [5].  Epidemiology Infection and illness Globally,  most  illnesses  caused  by  the  pandemic  (H1N1)  2009  virus  were  acute  and self-limiting,  with the highest  attack  rates reported  among children   and young  adults  [6].  The  median  age  of  most  of the  reported  cases was 12–25  years,  and  over  80%  of  cases  occurred  among  the age  group  of 5–49  years [7]. The overall  case  fatality  rate  amongst   the laboratory-confirmed  cases was less  than 0.5% [8].

Transmission The  mechanism  of person-to-person   transmission of pandemic  (H1N1)  2 0 0 9 v i r u s  a p p e a r e d  t o  b e  s i m i l a r  to  those  of  seasonal  influenza  [6].  The  main  route  of  transmission  was  reported  to be  respiratory  through  inhalation  of large-particle  respiratory  droplets, and possibly  via droplet  nu - clei [9].  Explosive  outbreaks  and am - plifications  of  cases  have  been  noted  in  schools  and closed  community   settings [10].  Clinical features Incubation period The  incubation  period was approxi - mately  1.5–3 days, which  is similar  to  that  of seasonal  influenza  [6,9]. Children  and immunocompromised  or immuno- suppressed  persons were contagious  for  longer periods.  Clinical presentation The clinical  manifestations  of pandemic  (H1N1)  2009  virus  infection  varied,  ranging  from afebrile  upper respiratory  illness  to fulminant  viral pneumonia. Most  patients  presenting  for  care  showed  typical  influenza-like  illness  with  fever  and cough,  sometimes  ac - companied by sore  throat  and rhinnor - rhoea [11,12].

Risk groups and risk factors for severe disease Underlying  medical  conditions  which   are associated  with complications  from  seasonal influenza  were also risk fac - tors  for complications  from pandemic   (H1N1) 2009 virus infection.  Globally,  nearly three quarters  of cases  requiring  hospitalization  involved  one  or  more  underlying  medical conditions  includ - ing asthma,  diabetes,  heart  or  lung  disease,  neurologic  disease,  pregnancy,  morbid  obesity,  autoimmune  disorders  and associated  immunosuppressive  therapies [13,14].  Clinical management The  majority  of  individuals  infected  with  pandemic  (H1N1)  2009  virus  were  treated  with  simple  supportive  care  at  home  using  antipyretics  (e.g.  acetaminophen or ibuprofen).  The  pandemic  (H1N1) 2009 virus  infection  was susceptible  to the  neu - raminidase  inhibitors oseltamivir  and  zanamivir,  but was  almost  always re - sistant to amantadine  and rimantadine  [15–17].  Early empirical  treatment  with  neuraminidase  inhibitors  in  patients  with  pandemic  (H1N1) 2009 infection  has been  shown  to  have  reduced  the  duration  of  hospitalization  [18]  and  the  risk  of progression  to severe  disease  requiring  ICU admission  or resulting  in  death [14]. Empiric antiviral  therapy  needs  to  be  started  for  persons  with  suspected,  probable  or confirmed  cases of pan - demic (H1N1) 2009 infection for: Illness requiring hospitalization • Progressive,  severe  or  complicated  • illness  regardless  of  previous  health  status and/or High  risk  groups  for  severe  disease,  • which include:

Children younger than 2 years – Pregnant  women  up  to  2  weeks  – post  partum  (regardless  of how  the  pregnancy ended) Adults 65 years of age or older – Persons  younger  than  19  years  – who  are  having  long-term  aspirin  therapy Persons  with  medical  conditions  – including  asthma, neurological  and  neurodevelopmental  conditions  (including  disorders  of  the  brain,  spinal  cord,  peripheral  nerves  and  muscles,  such  as  cerebral  palsy)  chronic  obstructive  lung  disease,  cardiac  disease,  diabetes  mellitus,  immunosuppressive  conditions (in - cluding HIV/AIDS, and cancer).

Clinicians  should consider  empiric  treatment  with  antibacterial  drugs  if  bacterial  co-infections  are  suspected  during  or  after  influenza.  The  use  of  high  dose  corticosteroids  for pandemic  (H1N1)  2009 infection  is controver - sial;  low-dose  steroids may, however,  be  EMHJ   •  Vol. 17 No. 4  •  2011 Eastern Mediterranean Health JournalLa Revue de Santé de la Méditerranée  orientale 344 considered in patients  with septic  shock  who require vasopressors [19–21].  Development of guidelines: expert consultation In order  to  support  the  countries  of  the  WHO  EMR  to  manage  human   cases infected  with pandemic  (H1N1)  2009 virus  in  a  standardized  way,  the  Regional  Office convened  an inter - national  expert  consultation  meeting  from  9  to  10  September  2009.  The  purpose  of  this  meeting  was  to  develop  a  clinical  management  guideline in or - der  to optimize  clinical care for human   infections  with  pandemic  (H1N1)   2009 virus  across  all  countries  in  the  Region.  Medical  experts in the  field  of pul - monology,  infectious diseases, public  health,  epidemiology,  internal medi - cine, intensive  care,  microbiology  and  virology  came  together  and  reviewed  the  available  international  guidelines  [22,23],  published  evidence and un - published  data  on  epidemiology  and  clinical  manifestations  of  the  disease.  Following  this expert  consultation,  an  interim  guidance  and  algorithms  were  developed  on clinical  management   of pandemic  (H1N1) virus infection   [24]. The  algorithms  were  intended  to  be  used  as  a  decision  tree  by  clinicians  to  exercise  their  clinical  judgment  for  treatment  and care  of patients  with  pandemic H1N1 virus infection. The  interim  guidance  on clinical   management  of pandemic  (H1N1)  2009 virus infection  used 4 case  defi - nitions  of  influenza  (Table  1)  for  the  purpose  of clinical  diagnosis  and initial  treatment  decisions. These include  (i)  influenza-like  illness  (ILI),  (ii)  severe  acute  respiratory  infection  (SARI),  (iii)  acute  respiratory  infection (ARI)  and (iv)  influenza  caused by pandemic  (H1N1) 2009 virus infection.  Three  categories  of clinical  manifes - tations have  been  seen during  the  cur - rent  pandemic  [13,14]  and  these  have  been  presented  in the  WHO  Regional   Office Interim Guidance:  Mild illness  characterized  by  fever  • (some  patients  had no fever),  cough,  sore throat,  diarrhoea,  myalgias, head - ache. Other  frequent  findings  have  included  chills and malaise.  Vomiting  and diarrhoea  have been  reported  in  some patients,  but  no  shortness  of  breath,  dyspnoea,  or severe  dehydra - tion.

Progressive  illness  characterized  • by  mild  illness  with  clinical  signs  or  symptoms  suggesting  a  progression  to  severe  illness,  which include  the fol - lowing  signs and symptoms  (Table 2  shows differentiation  between clinical  signs in adults  and in children  under  5 years) :

chest pain, tachypnoea,  or laboured  – breathing in children hypotension – confusion or altered mental status – severe  dehydration  or exacerba - – tions  of  a  chronic  conditions  (e.g.  asthma, cardiovascular conditions) Table 1 Case definition of influenza caused by pandemic (H1N1) 2009 virus infection Influenza-like illness (ILI) A person with sudden onset of fever > 38 °C and ≥ 1 of the following 2 respiratory symptoms in the absence of other known causes: dry cough, sore throat Severe acute respiratory illness (SARI) A person meeting the case definition of influenza-like illness (above) AND shortness of breath OR difficulty in breathing requiring hospital admission. Acute respiratory infection (ARI) Acute respiratory tract illness that is caused by an infectious agent transmitted from person to person. The onset of symptoms is typically rapid, over a period of hours to several days. Symptoms include fever, cough, and often sore throat, coryza, shortness of breath, wheezing, or difficulty breathing. Confirmed case of Pandemic (H1N1) 2009 An individual with an influenza-like illness with laboratory confirmed pandemic (H1N1) 2009 virus infection by ≥ 1 of the following tests:real time reverse-transcription polymerase (RT-PCR) viral culture. Probable case of Pandemic (H1N1) 2009 An individual with an influenza-like illness who is positive for influenza A that is unsubtypable by real-time PCR, ORAn individual with a clinically compatible illness or who died of an unexplained acute respiratory illness who is considered to be epidemiologically linked to a probable or confirmed case. Suspected case of Pandemic (H1N1) 2009 An individual with acute respiratory illness and fever (reported or documented fever), and one of the followings; cough, sore throat, shortness of breath, difficulty in breathing or chest pains with onset:within 7 days of close contact with a person who is a probable or confirmed case of pandemic (H1N1) 2009 virus infection, ORwithin 7 days of travel to a country/community where there has been one or more confirmed cases of pandemic (H1N1) 2009 virus infection, ORResides in a community where there is one or more confirmed cases of pandemic (H1N1) 2009 virus infection. طسوتلما قشرل ةيحصلا ةلجلما شرع عباسلا دلجلما عبارلا ددعلا 345 Severe illness  characterized  by  the  • following:

profound  hypoxemia,  abnormal  – chest  radiograph,  and  mechanical  ventilation encephalitis or encephalopathy – shock, multisystem organ failure – myocarditis and rhabdomyolysis – invasive  secondary  bacterial  infec - – tion (e.g. pneumococcal disease).

When  influenza  viruses  are  known   to be  circulating  in  the  community,  patients  presenting  with mild  influenza  can be diagnosed  on clinical  and epide - miological  grounds alone. Based  on the  clinical  evidence  and judgment,  the In - terim  Guidance  recommends  empirical  antiviral therapy  with  a  neuraminidase  inhibitor  in  appropriate  dose  (Table  3)  as  soon  as  possible  (i)  whenever  the  illness  requires  hospitalization;  (ii)  whenever  the  person  shows  signs  of  progressive  illness; (iii) and/or  when - ever the person  belongs  to the  high  risk  group for severe disease.  The clinical  algorithms  (Figures  1  and  2)  for  management  of  patients  with  pandemic  (H1N1)  2009  virus  infection,  as  presented  in  the  Interim   Guidance,  can be applied  to every  pa - tient diagnosed  on  the  basis  of  clinical   suspicion  alone  without  waiting  for  laboratory  confirmation.  The Interim   Guidance,  however, emphasizes  that all  patients  treated at home  need to be  in - structed  to return  for follow-up  should  they develop  any signs  or symptoms  of  progressive  disease  or  fail  to  improve  within  72 hours  of the  onset  of symp - toms.

Future directions As of  10  August  2010,  the  world  has  moved  into  the  post-pandemic  period  [25].  Based  on the  knowledge  about  past influenza  pandemics,  pandemic  (H1N1) 2009 virus is expected  to con - tinue  to  circulate  as  a  seasonal  virus  for  some  years  to  come  [25].  While  the  level  of concern  might have greatly  diminished,  vigilance  on  the  part  of  national  health  authorities  as  well  as  treatment  of  all  suspected  influenza   cases with standard  care remain  criti - cal in the  immediate  post-pandemic   Table 2 Clinical signs indicating rapid progression and need for urgent medical care In adults In children Difficulty in breathing or shortness of breath Tachypnoea or laboured breathing Pain or pressure in the chest or abdomen Skin colour change, grey or blue Episodes of sudden dizziness Inadequate intake of oral fluids Severe or continuous vomiting Severe or continuous vomiting Influenza-like illness that improves but then returns with fever and cough Influenza-like illness that improves but then returns with fever and cough Confusion Irritable or not waking up Table 3 Treatment regimen for Oseltamivir and Zanamivir for human infection caused by pandemic (H1N1) 2009 virus Age group Treatment (5 days) Chemoprophylaxis (10 days) Oseltamivir Adults 75 mg twice per day 75 mg once per day Children (≥ 12 months) ≤ 15 kg 30 mg twice per day 30 mg once per day 15–23 kg 45 mg twice per day 45 mg once per day 20–40 kg 60 mg twice per day 60 mg once per day > 40 kg 75 mg twice per day 75 mg once per day Children 3 – < 12 months 3 mg/kg/dose twice per day 3 mg/kg/dose once per day 0 – < 3 months 3 mg/kg/dose twice per day Not recommended, unless situation judged critical (limited data) Zanamivir Adults 2 × 5 mg inhalations (10 mg total) twice per day 2 × 5 mg inhalations (10 mg total) once per day Children ≥ 7 years for treatment; children ≥ 5 years for chemoprophylaxis 2 × 5 mg inhalations (10 mg total) twice per day 2 × 5 mg inhalations (10 mg total) once per day EMHJ   •  Vol. 17 No. 4  •  2011 Eastern Mediterranean Health JournalLa Revue de Santé de la Méditerranée  orientale 346 period since the behaviour  of pandemic  (H1N1)  2009 virus can not be reliably  predicted. The  Interim  Guidance  and  the  algorithms  for clinical  management   of human  infection  with pandemic   (H1N1) 2009  virus  were  developed  in  September  2009 based  on clinical   evidence  and best  clinical  outcome  fol - lowing available  treatment  practices  known  globally  at that  time.  The Interim  Guidance  and  its  clinical  algorithms  were  adopted  by many  countries  in the  Region.  It is expected  that this Interim   Guidance  will pave  the way  towards  de - veloping  national clinical management   protocols for  influenza  as  well  as  other  epidemic-  and  pandemic-prone  acute  respiratory  infections  in  the  countries  of  the  Region.  The uncertain  evolution  of the  pandemic  virus, however,  high - lights the importance  that the treatment  guidelines  and the supplementary   algorithms need  to  be  revised  and  continuously  updated  as  soon  as  new  evidence  on  clinical  manifestation  of  influenza  in  the  post-pandemic  period,  antiviral  resistance  pattern, effective - ness of the  currently  available antivirals,  and virulence  of the  circulating  seasonal  influenza virus become  available  in the  post-pandemic period.  No symptoms of ILI Assess and treat as indicated Direct patient to triage area for assessment Assess general state and hydration, measure body temperature (> 38 °C/100.4 °F) 1. Measure respiratory rate 2. Observe colour of skin, nails and mucosa 3. Perform pulmonary auscultation to identify crepitation 4.

Does patient have influenza-like illness (ILI) (temperature > 38 °C + dry cough or sore throat)? Patient has clinical signs of severe illness indicating rapid progression (detailed in Table-2) Apply home isolation and manage the patient at home DO NOT AUTHORIZE ANTIVIRAL TREATMENT AUTHORIZE ANTIVIRAL TREATMENT IMMEDIATELY Apply home isolation and manage the patient at home Immediately refer the pa - tient to secondary level care for hospitalization and further necessary treatment Standard and droplet precautions Patient: Surgical mask Staff: Hand hygiene, mask, gown and gloves Community protectionPatient: wears surgical mask, covers mouth and nostrils when coughing or sneezing and frequently washes hands The patient:Avoids public transport .uses a surgical mask .Covers mouth and .nostrils during coughing and sneezingAvoids close contact . Patient has mild ILI with no signs of severe illness BuT is in a high risk group for complications Patient has mild ILI (i) without any signs of severe illness and (ii) not in a high risk group Yes No Yes Yes Yes Infection control measures Figure 1 Algorithm for clinical management of patients at the primary health care level Assessment of patients طسوتلما قشرل ةيحصلا ةلجلما شرع عباسلا دلجلما عبارلا ددعلا 347 Figure 2 Algorithm for clinical management of patients at secondary or tertiary health care level One of  the  best  ways  to  evaluate  this  Interim  Guidance  would  be  to  assess  the  diagnostic  validity  of  its  clinical  algorithms  prospectively  in  some  selected  clinical  settings  that   should  include  both  resource-inten - sive  and resource-limited  countries. The effectiveness  of  clinical  algorithms  in  truly  detecting  patients with sus - pected  influenza  needs  to  be  assessed.  Solid  data on such  an evaluation  will in - crease  the  sensitivity  and  specificity  of  the  clinical  algorithms  of  the  guidelines  in  detecting  and  identifying  patients  with  suspected  influenza, guide treat - ment decisions  in the  post-pandemic   period, and ensure  that no cases  with  potentially  fatal outcome  are missed  by  clinicians  when  using  these  algorithms  as  a decision  tree to exercise  their clini - cal judgement.  Yes No Yes Infection control measures Assessment of patients The patient is showing clinical signs of illness indicating rapid progression and need for urgent medical care (Detailed in Table 2) Refer case for home management Immediately hospitalize patient Manage case at home AUTHORIZE ANTIVIRAL TREATMENTimmediately along with other supportive treatment Patient’s condition is improving and responding to treatment as indicated by:Becoming afebrile; .Tolerating oral fluid; .Absence of dyspnoea; .No evidence of dehydration; .Respiratory rate ≤ 30 bpm .Oxygen saturation ≥ 92% .underlying chronic health condi - .tions not exacerbated (for patients in high risk group for complica - tions) Patient’s condition is not improving and not responding to treatment as indicated by:Progressive pulmonary infiltrates .Persistent hypoxia (Sp O . 2 < 92%) despite maximum oxygen saturation;Progressive hypercapnoea; .Presence of compromised .haemodynamics;Signs of sepsis and imminent .shock Consult specialist for advice and admission to Intensive Care unit (ICu) Standard and droplet precautions Patient: Surgical mask and strict isolation or cohorting. Isolation precaution may be discontinued after the patients has received anti - viral treatment for 72 hours and remained afebrile for 24 hours even in the absence of antipyretics.

Staff: Hand hygiene, mask, gown, gloves and eye protection if there is a risk of splash. Standard and droplet precautions Patient : Surgical mask Staff : Hand hygiene, mask, gown and gloves In addition to the above, patient is presenting with:Refractory hypoxaemia .Compromised haemo- .dynamicsSigns of sepsis and immi - .nent shock Discharge criteria met Discharge the patient with proper advice (Patients should be discharged after receiving the full 5-day course of antivirals or 24 hours after becoming afebrile, whichever is earlier) Consider admission to ICu on advice from specialists EMHJ   •  Vol. 17 No. 4  •  2011 Eastern Mediterranean Health JournalLa Revue de Santé de la Méditerranée  orientale 348 References López-Cervantes M et al. On the spread of the novel influ - 1. enza A (H1N1) virus in Mexico. Journal of Infection in Developing Countries , 2009, 3:327–330. Influenza-like illness in the United States and Mexico, 2009. 2. Geneva, World Health Organization, 2009 (http://www.who.int/csr/don/2009_04_24/es/index.html, accessed 26 May 2009).

Pandemic (H1N1) 2009—update 60. 3. G e n e v a , W o r l d Health Organization, 2009 (http://www.who.int/csr/don/2009_10_02/en/index.html, accessed 5 October 2009).

Pandemic (H1N1) 2009—update 112. 4. G e n e v a , W o r l d Health Organization, 2009 ( http://www.who.int/csr/don/2009_1204/3n/index.html, accessed 10 August 2010).

Pandemic (H1N1) 2009 update. 5. Cairo, World Health Organiza - tion. Eastern Mediterranean Regional Office, 2009. (http://www.emro.who.int/csr/h1n1/index.html, accessed 10 June 2010).

Writing Committee of the WHO consultation on clinical as - 6. pects of pandemic (h1n1) 2009 influenza. Clinical aspects of pandemic 2009 influenza A (H1N1) virus infection. New Eng - land Journal of Medicine , 2010, 362:1708–1719. Pandemic influenza A (H1N1) 2009 virus. 7. Weekly Epidemiologi - cal Record , 2009, 85(49):505–516. Wilson N, Baker MG. The emerging influenza pandemic: esti - 8. mating the case fatality ratio. Euro Surveillance , 2009, 14(26):pii 19255.

Yang Y et al. The transmissibility and control of pandemic influ - 9. enza A (H1N1). Science , 2009, 326:729–733. Lessler J et al. Outbreak of 2009 pandemic influenza A (H1N1) 10. at a New York City school. New England Journal of Medicine , 2009, 361:2628–2636.

Cao B et al. Clinical features of the initial cases of 2009 pan - 11. demic influenza A (H1N1) virus infection in China. New England Journal of Medicine , 2009, 361:2507–2517. Hackett S et al. Clinical characteristics of paediatric H1N1 ad - 12. missions in Birmingham, uK. Lancet , 2009, 374:605–606. Human infection with new influenza A (H1N1) virus, clinical 13. observation from Mexico and other affected countries. Weekly Epidemiological Record , 2009, 84(21):185–196. Jain S et al. Hospitalized patients with 2009 H1N1 influenza 14. in the united States, April–June 2009. New England Journal of Medicine , 2009, 361:1935–1944. Itoh Y et al. In vitro and in vivo characterization of new swine 15. origin H1N1 influenza viruses. Nature , 2009, 460:1021–1025. Oseltamivir-resistant pandemic (H1N1) 2009 influenza virus 16. . Stockholm, European Centre for Disease Prevention and Control, 2009 (http://www.ecdc.europa.eu/en/activities/sciadvice/tests, accessed 10 December 2009).

Antiviral treatment options including intravenous peramivir for 17. treatment of influenza in hospitalized patients for 2009–2010 season . Atlanta, united States Centers for Disease Control and Prevention, 2009 (http://www.cdc.gov/ h1n1flu/EuA/Peramovir-recommendations.html, accessed 2 December 2009).

Patients hospitalized with 2009 pandemic influenza A (H1N1) 18. — New York City, May 2009. MMWR Morbidity and Mortality Weekly Report , 2010, 58:1436–1440. Intensive care patients with severe novel influenza A (H1N1) 19. virus infections. Michigan, June 2009. MMWR Morbidity and Mortality Weekly Report , 2009, 58:(27):749–752. Gomez-Gomez A et al. Severe pneumonia associated with 20. pandemic (H1N1) 2009 outbreak, San Luis Potosí, Mexico. Emerging Infectious Diseases , 2010, 16(1):27–34. Al Hajjar S, McIntosh. The first influenza pandemic of the 21st 21. century. Annals of Saudi Medicine , 2010, 30(1):37–46. Clinical management of human infection with Pandemic H1N1: 22. revised guidance . Geneva, World Health Organization, 2009 (www.who.int/entity/csr/resources/publications/swineflu/clinicalmanagement/en, accessed 07 November 2009 Updated interim recommendation from the use of antiviral 23. treatment and prevention of influenza from 2009–2010 season . Atlanta, Georgia, Centers for Disease Control and Prevention, 2009 (http://www.cdc.gov/h1n1flu/recommendations.htm, accessed 7 December 2009).

Clinical management of pandemic H1N1 2009 virus infection. 24. Interim guidance from Expert Consultation . Cairo, World Health Organization, Eastern Mediterranean Regional Office, 2009 (http://who.emro.who.int/csr/h1n1/clinical_management.htm, accessed 10 October 2009).

Recommendations for the post-pandemic period. 25. Geneva, World Health Organization, 2009 (Pandemic (H1N1) 2009 brief - ing note 23) (http://www.who.int/csr/disease/swineflu/notes/briefing_20100810/en/index.html, accessed 5 Octo - ber 2010).