NOVEL INFLUENZA A (H1N1) Swine Flu

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1 Introduction Definitions Influenza-like Illness Emergency Department Assessment Anitiviral Medication Oseltamivir (Tamiflu) Dosing Infection Control Issues Staff Exposure References Introduction This guideline has been adapted for the Starship Children s Hospital based on a number of other guidelines (including the Royal Children s Hospital Melbourne and the Ministry of Health). At this time there is very little evidence for a number of the recommendations, so the recommendation has been made based on commonsense and practicality. As more evidence becomes available these guidelines can be expected to change. Ministry of Health Definitions Confirmed case A confirmed case of novel influenza A H1N1 virus infection is defined as a person with laboratory confirmed novel influenza A H1N1 virus infection by one or more of the following tests: real-time RT-PCR viral culture (not currently being performed during pandemic) four-fold rise in novel influenza A H1N1 virus specific neutralising antibodies (not available at LabPlus) Probable case A probable case of novel influenza A H1N1 virus infection is defined as a person with an influenza like illness* who has a strong epidemiological link to a confirmed case or defined cluster. Close contact Close contact is defined as having cared for, lived with, or had direct contact with respiratory secretions or bodily fluids of a probable or confirmed case. Novel Influenza A (H1N1) Swine Flu Page: 1 of 5

2 Influenza-like like illness: Starship Children s Health Clinical Guideline (i) (ii) History of fever, chills, and sweating or clinically documented fever 38 C, PLUS cough or sore throat Other features to consider in children include body aches, fatigue, tiredness and shortness of breath. This is not all inclusive but will help with detection of children most likely to have influenza. Children under 12 months of age may have an even more non-specific illness. Surveillance studies suggest a low rate of influenza as a cause of acute wheezing illnesses in children. Recent reports suggest children with influenza can present with neurologic complications such as seizures or encephalopathy. When assessing children with Influenza-like illness consideration needs to be given to the possibility of influenza with a secondary bacterial infection (eg. pneumococcal or staphylococcal disease) or bacterial infection with non-specific symptoms presenting similarly to influenza such as meningococcal disease. These possibilities would warrant use of appropriate antibiotics. Co-morbidities, particularly immune suppression, chronic lung disease and morbid obesity, are risk factors for more serious disease. Long term aspirin therapy is a risk factor for Reye s syndrome with influenza. Emergency Department Assessment Patient assessed to be well enough for discharge: No viral investigations are needed unless the child is in a residential care facility such as Wilson Home or boarding school. Recommend patients stay at home until symptoms are resolved Most patients do not require oseltamivir (Tamiflu). Oseltamivir should be given as treatment (see below) if patient has risk factors for more serious disease. These children should be discussed with the CED specialist on duty. All children commenced on oseltamivir should be notified to Public Health. Prophylaxis (see below) should only be given to close family members if they have risk factors for serious disease. Symptomatic family members should not stay in the hospital or at Ronald McDonald house. Novel Influenza A (H1N1) Swine Flu Page: 2 of 5

3 Unwell patient being admitted to hospital Patient requires respiratory isolation on ward Appropriate viral swab taken to confirm diagnosis and for cohorting purposes Oseltamivir started if fulfils case definition (confirmed or probable) and are either moderately/severely unwell or have co-morbidities Most children who are started on oseltamivir will also require initiation of antibiotics (see Starship pneumonia guideline). The worst disease in young adults seems to be in those with early bacterial superinfection awareness and early initiation of antibiotics are required to minimise this. Antiviral Medication See separate Auckland Hospital guidelines for outpatient oseltamivir prescribing. Oseltamivir has not been widely tested or used in children under 12 months of age, but can be considered for hospitalised patient with risk factors. Clinical judgement should be used weighing risks of disease against unknown risks of oseltamivir. There is even less information about use of oseltamivir in infants under 3 months of age. Discuss with Paediatric Infectious Disease specialist on call if considering this. Oseltamivir may reduce duration of illness, severity of illness and duration of viral shedding. Best results occur if treatment begins within hours of symptoms starting. Please note that Seasonal H1N1 influenza is likely to be oseltamivir-resistant and it should not be used in such cases. Oseltamivir (Tamiflu) Dosing For patients who cannot swallow capsules, Tamiflu oral suspension is the preferred formulation. The suspension is available as 12mg/ml. Doses in this guideline for children < 1 year are based on 2 to 3mg/kg per dose and have been adjusted to account for the strength of the suspension. The bottle comes with a dispenser marked for 30, 45 & 60 mg which should not be used for doses less than 30mg. Provide patients with an oral syringe instead (e.g. 3 ml or 5 ml) to measure doses and give instructions in ml. If the oral suspension is not available, dissolve contents of capsule in 5 ml water using graduated syringe; mix well and withdraw required dose. May be mixed with sweetened liquids/ food to mask the bitter taste of the medication. Novel Influenza A (H1N1) Swine Flu Page: 3 of 5

4 Children < 1 year 3 kg 6mg twice daily for 5 days >3 to 4 kg 9mg twice daily for 5 days >4 to 6 kg 12mg twice daily for 5 days >6 to 9 kg 18mg twice daily for 5 days >9 to 12 kg 24mg twice daily for 5 days >12 to 14 kg 30mg twice daily for 5 days Children > 1 year < 15 kg 30 mg twice daily for 5 days 15 to 23 kg 45 mg twice daily for 5 days 23 to 40 kg 60 mg twice daily for 5 days Adolescents and children > 40kg >40 kg 75 mg twice daily for 5 days Notes: Refer to product datasheet for further prescribing information. Adjust dosing for renal failure and dialysis. Discuss with Paediatric Renal team or Paediatric Pharmacist. Give doses with food to minimise GI upset. If vomiting occurs within 30 minutes of administration a repeat dose should be given. For post-exposure prophylaxis use the same dose but ONCE daily for 10 days. Novel Influenza A (H1N1) Swine Flu Page: 4 of 5

5 Infection Control Issues See also local Hospital guidelines Careful hand hygiene and social distancing remain the most effective way to reduce the spread of infection There is no consensus on duration of isolation in hospital. The decision will be influenced by the presence of underlying disease (eg. chronic respiratory disease or immunosuppression), patient age and the use of antiviral medication. 5 years with no co-morbidities, immunosuppression or underlying significant respiratory disease (excluding asthma): Take out of isolation after 5 days of oseltamivir or if no antiviral taken after 7 days of illness with resolution of symptoms < 5 years with no co-morbidities, immunosuppression or underlying significant respiratory disease (excluding asthma): Take out of isolation after 5 days of oseltamivir or if no antiviral taken after 10 days of illness with resolution of symptoms. Younger children are believed to excrete virus for longer periods. If immunosuppressed or significant respiratory disease eg bronchiectasis remain in isolation for length of hospital stay. Can be discussed with Paediatric Infectious Disease specialist on call. Staff exposure See Local Hospital Guidelines References: Medsafe Data sheet (Tamiflu ) [Datasheet online] Roche Products. Updated: 1 May 2009 Available from URL: Royal Children s Hospital Melbourne, Oseltamivir doses in children Version 5, 1 June 2009 For further information please visit: Novel Influenza A (H1N1) Swine Flu Page: 5 of 5