Swine Flu

What is swine flu?How swine flu presents?How to diagnose swine flu?How to treat swine flu? What are the vaccines for swine flu?How to prevent from getting swine flu?

1. Swine Flu Dr.S.Sesha Sai ,PG, Pulmonary Medicine

2. Swine in flu enza is a respiratory disease of pigs. Influenza A. Sometimes the existing strains of virus combine to form a new subtype. ( Antigenic Shift). In 2009, North American swine influenza, North American avian influenza, human influenza, and swine influenza virus typically found in Asia and Europe reassorted and formed a new subtype called H1N1. [2]

3. In US, Between 7,070 and 13,930 deaths were attributable to H1N1 flu from April to 14 November 2009. CDC estimates that between about 8,870 and 18,300 2009 H1N1-related deaths occurred between April 2009 and 10 April 2010. India had reported 937 cases and 218 deaths from swine flu in the year 2014. By mid-February 2015, the reported cases and deaths in 2015 had surpassed the previous numbers. The total number of laboratory confirmed cases crossed 33000 mark with death of more than 2000 people. Highest number of deaths are in Gujarat > Rajasthan.

4. History of Virus [3] Year of Origin Sub type 1890 H2N8 1900 H3N8 1918 H1N1 (Spanish) 1957 H2N2 (Asian) 1968 H3N2 (Hong Kong) 1977 H1N1 (Russian) 2009 H1N1 (Swine) 2013 H7N9 (Avian, China)

5. Virus (Agent) Orthomyxoviridae family ssRNA Spherical shape 80-120 nm Host All age groups Young Children >65 years HCWs, Co – morbids , Immunocompromised.

6. Environment Tropics/ Sub tropics: epidemics occur in rainy season Overcrowding : Mostly affect urban and peri -urban areas. Closed populations :High attack rates may be witnessed in Army Barracks, College hostels, Schools, Residential hostels of schools, aircrafts, ships etc

7. EM of Swine flu virus

8. Clinical features

9. Investigations RT – PCR (4 hours) or Isolation of virus in culture or Fourfold rise in virus specific neutralising antibodies. Sample Collection: Swabs (Nasopharyngeal, Throat, Nasal) Tracheal aspirate ( intubated ) Before administration of anti viral drugs 4 C in viral transport media within 24 hours. If not possible, Store at –70 C

10. Categorization [4]

11. Features Management A Mild fever + Cough or sorethroat ± bodyache , headache, diarrhea, vomiting No testing Does not require oseltamivir Monitor and reassess (24-48hr) B CAT A + any of High grade fever, Severe sore throat. Children with predisposing factors, Pregnant women , >65, Comorbids , Immunocompromised. No testing Home isolation Oseltamivir Broad spectrum antibiotics for CAP C CAT A + CAT B + one or more of Breathlessness, chest pain, drowsiness, hypotension, hemoptysis , cyanosis Children with Somnolence, high and persistent fever, inability to feed well, convulsions, dyspnea . Worsening of underlying chronic conditions. Testing Immediate hospitalization and treatment.

12. Infection control measures Frequent hand washing of personnel and contacts. Cough etiquettes and maintain arms length distance from others. Dedicated doctors, nurses and paramedical workers. Portable X Ray machine, ventilators, large oxygen cylinders, pulse oxymeter and other supportive equipments Adequate disinfectants and medications

13. Contd.. Use of face masks Isolation room or beds one meter apart. All those entering room wear protective gear. Prophylaxis to health care personnel. Waste disposal in biohazard labeled bags. Contact surfaces – wipe with sodium hypochlorite or 5% bleach

14. Use of face mask [5]

15. For General Public No scientific evidence to show health benefit of using triple layer masks for members of public. Erroneous use of masks or continuous use of a disposable mask for longer than 6 hours or repeated use of same mask may actually increase risk of infection further.

16. Oseltamivir ( Tamiflu ) Neuraminidase (NA) Inhibitor The drug should be given as BD dose for 5 days. Adults : Infants : It is also available as syrup – 12mg / ml Weight Dose < 15 kg 30 mg 15 – 23 kg 45 mg 24 – 40 kg 60 mg > 40 kg 75 mg Age Dose < 3 months 12 mg 3 – 5 months 20 mg 6 – 11 months 25 mg

17. Tamiflu should be given within 24-48 hrs. Adverse reactions of Oseltamivir No recommendation for dose reduction in hepatic disease. Dosage modification should be done in renal impairment Common Nausea, Vomiting Occasionally Bronchitis, Insomnia, Vertigo Less commonly Angina, Psuedomembranous colitis, Peritonsillar abscess Rare Anaphylaxis, Skin rashes

18. Other drugs… [6] Zanamivir ( Relenza ) : Dry powder inhalation Not effective in children, asthmatics Peramivir ( Rapivap , Rapiacta , Peramiflu ) : Only Intravenous drug available for Swine flu FDA approved for adults Single dose of 600 mg given.( $ 950) M2 Inhibitors – Amantadine , Rimantadine Developed resistance. No longer recommended by CDC. Laninamivir [7] – Phase III trials, Approved in Japan ( Inavir )

19. Supportive Therapy IV fluids, Parenteral Nutrition O2 / Ventilatory support Antibiotics, Vasopressors (shock) PCM / Ibuprofen – fever, myalgia , headache Plenty of fluids If SpO 2 < 90% and PaO 2 < 60 mmHg – Mechanical Ventilation Preferred – Invasive High dose corticosteroids – No benefit, Potential harm Low dose ( Hydrocortisone 200 – 400 mg / day) – in persistent septic shock SALICYLATES are CONTRAindicated – REYE syndrome

20. Ventilator Protocol Pressure pre-set (controlled) Low tidal volume ventilator support Tidal volume — 6 ml/kg ideal body weight (Respiratory rate to a maximum of 30- 35 per minute). Open lung strategy of ventilation PEEP titration to keep the lung recruited to achieve an FIO2 of < 0.5 and a saturation of > 90% or a PaO2 of > 60 mmHg Plateau (Pause) pressure not to exceed of > 30-35 mmHg. APRV (Airway Pressure Release Ventilation), IRV (Inverse Ratio Ventilation) in patients with persistent Hypoxemia.

21. Discharge Policy Adults – 7 days after symptoms have subsided. Children – 14 days after symptoms have subsided.

22. Complications Sinus / Ear infections Bacterial pneumonia ( MRSA,MSSA,Group A strep) Bronchiolitis , Croup, Diarrhea Febrile seizures Rhabdomyolysis Encephalopathy / Encephalitis Myocarditis , Pericarditis Exacerbation of chronic illness (COPD, Diabetes, Coronary artery disease) Reye syndrome Toxic shock syndrome Sudden death

23. Preventive care for contacts OD dose of Oseltamivir according to body weight till 10 days after last exposure ( Upto 6 weeks) Not recommended for infants < 3 months

24. Vaccination [8] Prioritized groups Heath Care Workers – Medical and paramedical staff in Casualty, ICU, Isolation ward, Screening centers. All pregnant women. Chronic illnesses. > 65 years, 6 months – 8 years. Takes about 2 – 3 weeks to develop immunity. Administered at least One month prior to commencement of season.

25. Currently available vaccine is Northern Hemisphere Trivalent Vaccine Inactivated trivalent vaccine (SC/IM) . Vaccination should occur before onset of influenza activity in the community Can be used till May 2017. In India, Influgen ( Lupin ), Costs ₹ 720. Also Vaxigrip ( Sanofi Pasteur), Costs ₹ 550

26. Strains in the vaccine [9 ] : A/California/2009 (H1N1)–like virus A/Hong Kong/2014 (H3N2)–like virus B/Brisbane/2008–like virus Quadrivalent vaccines will include an additional vaccine virus strain , B/ Phuket /2013–like virus Contraindicated in Egg allergy and GBS.

27. References Clinical Management Protocol for Seasonal Influenza H1N1, Ministry of Health and Family Welfare, Directorate General of Health Sciences, October 21, 2016. The 2009 H1N1 Pandemic: Summary Highlights , CDC. Paul M.; “Origin of Human Diversity” , Vol 108, Feb 8, 2002 and Tokiko W.; “Pathogenesis of 1918 Pandemic history of influenza virus”, Feb 6, 2009. Guidelines on categorization of Seasonal Influenza cases during screening for home isolation, testing, treatment and hospitalization, MOHFW, DGHS, October 10, 2016. Guidelines on use of masks for health care workers, patients and members of public, MOHFW, DGHS. Influenza Antiviral Medications: Summary for Clinicians, Jan 25, 2017. Centre for Disease Control. https://www.ncbi.nlm.nih.gov/pubmed/21973296 . National Center for biotechnology information. Seasonal Influenza: Guidelines for Vaccination with Influenza Vaccine , MOHFW, DGHS, October 21,2016. Prevention and Control of Seasonal Influenza with Vaccines, Recommendations of the Advisory Committee on Immunization Practices — United States, 2016–17 Influenza Season, Aug 26,2016. Lisa A. Grohskopf , MD 1 ; Leslie Z. Sokolow , MSc, MPH 1,2 ; Karen R. Broder , MD 3 ; Sonja J. Olsen, PhD 1 ; Ruth A. Karron , MD 4 ; Daniel B. Jernigan, MD 1 ; Joseph S. Bresee , MD 1, CDC

28. Thank You