INFLUENZA A (H1N1)

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INFLUENZA A (H1N1) SPEAKER DR. KIRAN PATIL 2ND YR POST GRADUATE G.S.V.M. MEDICINE DEPTT. KANPUR. MODERATOR DR.B.P.PRIYADARSHI ASST.PROFFESSOR G.S.V.M. MEDICINE DEPTT. KANPUR.

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INFLUENZA A (H1N1). SPEAKER DR. KIRAN PATIL 2ND YR POST GRADUATE G.S.V.M. MEDICINE DEPTT. KANPUR. MODERATOR DR.B.P.PRIYADARSHI ASST.PROFFESSOR G.S.V.M. MEDICINE DEPTT. KANPUR. - PowerPoint PPT Presentation

Transcript of INFLUENZA A (H1N1)

Page 1: INFLUENZA  A (H1N1)

INFLUENZA A (H1N1)

SPEAKER

DR. KIRAN PATIL

2ND YR POST GRADUATE

G.S.V.M. MEDICINE DEPTT.

KANPUR.

MODERATOR

DR.B.P.PRIYADARSHI

ASST.PROFFESSOR

G.S.V.M. MEDICINE DEPTT.

KANPUR.

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What is Swine Flu

• Swine influenza virus (referred to as SIV) refers to influenza cases that are caused by Orthomyxovirus endemic to pig populations. SIV strains isolated to date have been classified either as Influenza(virus C or one of the various subtypes of the genus Influenza virus A)

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QUADRUPLE REASSORTMENT GENETICS • Human swine

SHIFT

• Avian swine

H1N1

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INFLUENZA VIRUS

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TYPES

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PIG THE CREATOR

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VIRAL VARIANTS

• INFLUENZA A VIRUS

• Swine Human Avian

• H1N2 H1N1(pandemics) H5N1

• H3N1 H3N2 (rare)

• H3N2

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EPIDEMIOLOGY• Incubation period- 1-7 days

• Transmission

PRIMARY CASE –direct contact with pigs

SECONDARY CASES

sneezing, coughing

resp droplets

body fluids(diarroeal stool) contact surfaces

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• This virus is not transmitted from eating pork or pork products

• Contagiousness:

1 day onset of symptoms

7 days

Children are contagious for longer periods.

. Majority of pts were previously healthy.

Clinical course mild in PCR negative influenza.

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Risk factors

• COPD

• Immunocompromised state

• DM

• Pregnancy

• Cardiac disease

• Obesity

• CHF ,Renal failure,hepatic failure

• Children <5 yrs, elder>65 yrs.

• Cancer.

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DEFINITIONS

• Influenza-like illness (ILI) is defined as fever (temperature of 100ºF [37.8ºC] or greater) with cough or sore throat in the absence of a known cause other than influenza

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Case Definitions By CDC

• A confirmed case acute febrile respiratory illness with laboratory-confirmed H1N1 influenza A virus detection by real-time reverse transcriptase (RT)-PCR or culture.

• A probable case acute febrile respiratory illness who is positive for influenza A, but negative for H1 and H3 by RT-PCR

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A suspected case acute febrile respiratory illness who:

•       - Develops symptoms within seven days of close contact with a person who is a confirmed case of H1N1 influenza A virus infection or

•       - Develops symptoms within seven days of travel or resides in a community where there are one or more confirmed H1N1 influenza A cases

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CLINICAL FEATURES

Vomiting or diarrhea (not typical for influenza but reported by recent cases of swine influenza infection)

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Other Manifestations:

• Tachycardia

• Tachypnoea

• Low O2 sat.

• Hypotension

• Cyanosis

• Acute myocarditis

• Cardiopulmonary arrest

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H1 N1 Pneumonia

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COMPLICATIONS

Similar to those of seasonal influenza• Exacerbation of underlying chronic medical

conditions • Upper respiratory tract disease (sinusitis, otitis

media, croup) • Lower respiratory tract disease (pneumonia,

bronchiolitis, status asthmaticus)

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• Cardiac (myocarditis, pericarditis)

• Neurologic (Acute and post-infectious encephalopathy, encephalitis, febrile seizures, status epilepticus)

• Toxic shock syndrome

• Secondary bacterial pneumonia with or without sepsis

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Children Emergency Warning Signs

• Fast breathing or trouble breathing

• Bluish or gray skin color

• Not drinking enough fluids

• Severe or persistent vomiting

• Not waking up or not interacting

• Being so irritable that the child does not want to be held

• Flu-like symptoms improve but then return with fever and worse cough

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In adults, emergency warning signs

• Difficulty breathing or shortness of breath

• Pain or pressure in the chest or abdomen

• Sudden dizziness

• Confusion

• Severe or persistent vomiting

• Flu-like symptoms improve but then return with fever and worse cough

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CATEGORISATION 14/8/09

• CATEGORY -A: Mild fever plus sore throat /cough with or without bodyache, headache,diarrohea/ vomiting.

CATEGORY-B(i) : A+ High grade fever and severe sore throat.

• B (ii) :A + HIGH RISK GROUPS.

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CATEGORISATION 14/8/09

• CATEGORY C: A/B + 1/MORE OF THE FOLLOWING

• Breathlessness,chest pain,drowiseness,hypotension,cynosis,irritability or worsening of the existing chronic condition.

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COMPARISION

SEASONAL INFLUENZA

H1N1 INFLUENZA

AGE <5 YRS >60 YRS YOUNG & MIDDLE AGE

SEVERITY LESS SEVERE PNEUMONIA ARDS

MORBIDITY LESS MORE BUT >60 YRS LESS LIKELY TO HAVE SEVERE PNEUMONIA

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contd

SEASONAL INFLUENZA

H1N1 INFLUENZA

SYMPTOMS RESPIRATORY RESPIRATORY & GASTROINTESTINAL

SECONDARY ATTACK RATE

5-15 % 22-33 %

VACCINE PROTECTIVE UNDER DEVELOPMENT

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DIAGNOSTIC TESTS

RT PCRRT PCR

QUIDELQUIDEL

CULTURECULTURE

DFA/IFADFA/IFA

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LABORATORY FINDINGS

• CBC- leucocytosis/leucopenia

lymphopenia

• Elevated CPK, LDH

• Elevated UREA,CREATININE

• Elevated AST,ALT

• CHEST RADIOGRAPH-bilateral patchy pneumonia.

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INVESTIGATIONS-Specimens • Nasopharyngeal swab, nasal swab, throat

swab, combined oropharyngeal/ nasopharyngeal swab, or nasal aspirate

• Swabs with a synthetic tip (eg, polyester or Dacron) and an aluminum or plastic shaft should be used. Swabs with cotton tips and wooden shafts are not recommended.

• The collection vial in which the swab is placed should contain 1 to 3 mL of viral transport media.

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• Respiratory specimen should be collected within 4 to 5 days of illness.

• Specimens should be placed in viral transport media and placed on ice (4ºC) or refrigerated immediately for transportation to the laboratory

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LAB TESTS• Real time RT PCR-confirmatory

• culture is usually too slow to help guide clinical management. A negative viral culture does not exclude pandemic H1N1 influenza A infection.

• Rapid antigen tests — evaluation of patients suspected of having influenza, but results should be interpreted with caution the QuickVue Influenza A+B (Quidel) assay (sensitivity 51 percent specificity 99 percent)

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• Rapid influenza antigen tests & Direct or indirect immunofluorescent antibody testing (DFA or IFA) can distinguish between influenza A and B but negative test does not exclude infection.

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TREATMENT• Only neuraminidase inhibitors

ORALTamiflu (oseltamivir) and Relenza( zanamivir) are approved to cure the viral infection.

• H1N1 is resistant to Amantadine Rimantadine

• Antiviral drugs can be given to treat those who become severely ill with influenza.

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Tamiflu (Oseltamivir )

• Block the active site of the influenza viral enzyme neuraminidase

• This effect results in viral aggregation at the host cell surface and reduces the number of viruses released from the infected cell

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Tamiflu

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Tamiflu

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Tamiflu(contd)

• If one dose missed?

take as soon as you remember unless it is within 2 hours of next dose

do not take two doses at a time

. With other medications?

minimal drug interaction

no intranasal flu vaccine(Flu Mist) within 2weeks before or 48 after taking tamiflu

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Tamiflu (Contd)

• With kidney disease

Flu treatment :one 75mg dose OD for 5 days

Flu prevention:one 75 mg dose alternate day or 30 mg dose OD

. Storage:

capsules- <25 degree C

liquid - 2 to 8 degree C

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Tamiflu(Cont)

• Side effects: GI ,occasionally bronchitis ..insomnia..vertigo,angina,pseudomembranous colitis,peritonsilar abscess.

• Price-2250 for 10 tabs.

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Zanamivir ( Relenza)

– It is not recommended for people with underlying respiratory disease such as asthma or chronic obstructive pulmonary disease or lactose intolerance

– Treatment of 7 year & older patients 10mg (2puffs)BID 5d

– Prophylaxis of 5 year & older patients 10mg OD 10d-28 days

• Status in India

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Hand washing

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N95 Mask

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What should I do to keep from getting the flu?

• First and most important: wash your hands

• Get plenty of sleep

• Drink plenty of fluids

• Try not to touch surfaces that may be contaminated with the flu virus.

• Avoid close contact with people who are sick.

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Avoid close contact

• Avoid close contact with people who are sick. When you are sick, keep your distance ( > 1 meter )from others to protect them from getting sick too.

• Aerosols spread the virus in any environment

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N95 RESPIRATORS

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Prevention

• management of the outbreak such as closure of schools, advising avoidance of mass gatherings and distribution of antivirals

• Avoiding close contact• Staying home from work, school• Covering mouth and nose with a tissue or

N95 mask (three layered) when coughing or sneezing. Change the mask every 6 to 8 hours

• Washing your hands

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Why do we need vaccine

COST EFFECTIVETARGET AT RISKPEOPLE

VACCINE

WINTER SEASONTO COME(LOW HUMIDITY,TEMP)

RAPID GLOBALSPREAD

SEASONAL VACCINEPROTECTION?

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Conclusion

• Be cautious but no need to panic

• Need for further guidelines beyond diagnosis & management.

• Judicious use of diagnostic tests

• Early suspecting and treating cytokine storm is very important

• Not to forget universal precautions