Influenza Virus

Influenza virus Presented by Teck Kim Tie

Topic will be covered include:~ 1)Introduction 2)Classification 3)Pathophysiology 4)Signs and symptoms 5)Treatment 6)Complication 7)Prevention 8)Diet requirement 9)Supplementary 10)Vaccination 11)conclusion

1) -

Introduction:’ Commonly referred as flu Different from common cold Can cause pandemic According to WHO divided into 6 phases. Seasonal influenza and H1N1 (2009)

2) Classification: -Influenza A, B and C a) influenza A- cause flu pandemics and infect humans, other mammals, and birds b) influenza B- infect humans and seals c) influenza C- infect humans and pigs - type A and C infect multiple species while influenza B almost exclusively infects humans -H1N1 (2009)- type A virus

3) Pathophysiology: -transmitted from infected mammals through the air by coughs or sneezes, creating aerosols containing the virus and from the birds through their droppings. - can also be transmitted by saliva, nasal secretions, feces and blood. - Haemagglutinin + sialic acid → endocytosis→ endosomes → H+ flows through M2 protein → release viral RNA plus accessory protein → nucleus → mRNA → ribosome → protein synthesis → assemble → released.

4) Signs and symptoms: -Chills - fever (38-39 -sore throat - muscle pain - severe headache - coughing - weakness and general malaise. -cause nausea and vomiting particularly in children

5) Treatment: a)Make sure the patient fulfills -Temperature ≥ 38 -Coughing -Sore throat -Within 48 hours of onset of symptoms -With co-morbidities i)Cardiac disease ii)Chronic respiratory disease iii)Chronic disease (DM, RF, haemoglobinopathies) iv)Chronic neurological disorders v)Impaired immunity vi)Children aged 6 months-10 years on long term aspirin therapy vii)Malnourished or obesity

Viii) Pregnant lady, especially 2nd and 3rd trimester iX) Extreme age groups : ≥ 65 years old Then:~ -Fill up borang A and attach the form with the prescription and send to pharmacy. -Inpatient and outpatient treatment -Only MO are allowed to prescribed the antiviral treatment -Pharmacy staffs need to fill in borang B and the nurse that is going to administered the medication need to fill in borang C - flu pamphlet and advice need to be given

-neuraminidase inhibitor and M2 protein inhibitors. -Only neuraminidase inhibitor, Oseltamivir and Zanamivir are used in hospital Malaysia because they are less toxic and more effective. - However M2 inhibitors, Amantadine and Rimantadine are used together with neuraminidase inhibitor in oseltamivir-resistant infection as empirical therapy as recommended by CDC.

Dosage of Oseltamivir (≥12 months, ≥ 40kg): -75mg bd for 5 days for treatment -75mg od for 10 days for prophylaxis Dosage of Zanamivir (≥ 5 years): -2 inhalation (10mg) bd for 5 days for treatment -2 inhalation (10mg) od for 10 days for prophylaxis Dosage for amantadine (10-65 years old): -100mg bd for 10 days for treatment. Dosage for Rimantadine: -

Dosing recommendation for Oseltamivir: Age

In-patient treatment for 10 days

Out-patient treatment for 5 days

< 3 months

20 mg bd

12 mg bd

3-5 months

25mg bd

20mg bd

6-11 months

30mg bd

25mg bd

15kg or less

45mg bd

30mg bd

16-23 kg

60mg bd

45mg bd

24-40kg

75mg bd

60mg bd

> 40kg

150mg bd

75mg bd

Children > 12 months

Side effect of the medications: 1)Oseltamivir- N, V, D, abdominal pain, headache 2)Zanamivir- bronchospasm, dyspnoea, allergic reaction 3)Amantadine- nervousness, depression, nightmares, hallucinations, insomnia, dizziness, heahace, blurred vision, constipation, dry mouth, orthostatic hypotension -All treatment must start within 48 hours of onset of symptoms for maximal benefits. -Treatment only decrease the severity of symptoms -immune system plays a vital role

Criteria for discharge of patients: -Has completed 5 days course of oseltamivir and at least 24 hours afebrile -Can be dischargeed earlier, after completing 3 days or 6 dosesas long as the patient does not have complications and afebrile for at least 24 hours and not from the high risk group. -Need further home isolation for a total of 7 days

6) Prevention: -Practise good personal hygeine is important to prevent transmission. -Frequent disinfection will destroy the virus as well -Cover your mouth when cough or sneeze -Wear a face mask

7) Complication: -Pneumonia -Ear infection -Sinus infection -Dehydration -Worsening of chronic medical condition

8) Diet requirement: -Drink plenty of hot fluid to promote excretion of toxin -Avoid diuretic like tea and coffee -Avoid dairy products -Avoid alcoholic drinks as it deplete vit C -Foods should be as light and easily digestable -Avoid high fat food -Eat a balance diet with plenty of vegetables and fruits -Mushrooms, contain compound that can boost the immune system - Avoid sweets, neutrophils become lethargic when you eat sweets

8) Food supplement: a)Vit C -At least 2g/day of intake proved to be beneficial -Start as early as you feel uncomfortable -Not suitable for kidney patient due to kidney stone accumulation b) Zinc -Proven to shorter cold compare to placebo -23g of zinc lozenge every 2 hours -Start ASAP until symptoms subside -Don’t use for longer than 1 week because it can suppress the immune system if used for an extended period of time.

e) Garlic: -Can help to boost immune system, 2 capsules tds f) Echinacea: -2 capsule tds for maximum of 8 weeks g) Ginseng: -

9) Vaccination: -trivalent influenza vaccine that contains purified and inactivated material from 3 viral strains. - typically from 2 influenza A virus subtypes and 1 influenza B virus strain. - carries no risk of transmitting disease and has very low reactivity. - for children, elderly, asthmatic, diabetes, heart diseases -H1N1 vaccine is expected to be available in the fall according to CDC.