Swine Flu Swine Flu

8/14/2019 Swine Flu Swine Flu

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SWINE FLUSWINE FLUSWINE FLUSWINE FLU

SYMPTOMS SIGNS ANDSYMPTOMS SIGNS AND

MANAGEMENTMANAGEMENT


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IS IT SWINE FLU OR H1N1 influenza

Swine Influenza Virus (SIV) is a strain of the influenza family ofviruses that is hosted by pigs.

As of 2009, the known SIV strains are the influenza C virus and thesubtypes of the influenza A virus known as H1N1, H1N2, H3N1,H3N2, and H2N3.

The 2009 swine flu outbreak in humans is due to a new strain ofinfluenza A virus subtype H1N1 that contains genes closelyrelated to swine influenza.

The origin of this new strain is unknown.

The World Organization for Animal Health (OIE) reports that this

strain has not been isolated in pigs.

This strain can be transmitted from human to human, and causes thenormal symptoms of influenza


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June 11World now at the start of 2009 influenza pandemic

Dr Margaret ChanDirector-General of the World Health Organization

On the basis of available evidence, and these expert assessments of the evidence,

the scientific criteria for an influenza pandemic have been met.I have therefore decided to raise the level of influenza pandemic alert from phase 5

to phase 6.The world is now at the start of the 2009 influenza pandemic.


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June 11 th :


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Clinical features

Fever,Cough,Sore Throat,Malaise, AndHeadache;Vomiting And Diarrhea, Both Of Which Are Unusual Features Of Seasonal Influenza.Chills, Myalgias, And Arthralgias.

In New York City, 95 percent of patients with H1N1 influenza A have met the casedefinition for influenza-like illness (subjective fever plus cough and/or sore throat).

One third of patients seen at two hospitals in Mexico had no fever at presentation. Certain groups, such as infants, elderly individuals, and immunocompromised hosts, may have

atypical presentations. The full range of complications of infection with the current strain of H1N1 influenza A is

not yet known, although fatal and non-fatal cases of pneumonia have occurred.


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ComplicationsExacerbation of underlying chronic medical conditions

Upper respiratory tract disease (sinusitis, otitis media, croup) Lower respiratory tract disease (pneumonia, bronchiolitis, status

asthmaticus) Myocarditis, Pericarditis Acute and post-infectious encephalopathy,

Encephalitis, Febrile seizures, Status epilepticus)

Toxic shock syndrome ARDS

Secondary bacterial pneumonia with or without sepsis


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When to investigate ??

Whom to investigate ??

How to investigate ??


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Incubation period 10 days :

Clinical criteria -

Fever > 37.5 C and signs of respiratory infectionPneumonia

Death from unexplained respiratory illness

With atleast one epidemiological criteria

Travel to area where there are new confirmed cases

Close contact with new confirmed case of influenza

Laboratory criteria atleast one of the following positive testRT PCR

Four fold increase in neutralising antibodies

Viral culture


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Case classification

A Case under investigationAny person meeting clinical and epidemiological criteria

B Probable caseAny person meeting clinical and epidemiological criteria andconfirmed influenza A virus infection but un subtypable

C Confirmed caseAny person with laboratory confirmation.


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Investigation

Real-time RT-PCR is the recommended test for confirmation of influenza A (H1N)1 cases.Rapid influenza antigen test

Differentiates between A and B influenza virus

Unknown specificity and sensitivity

Immunofluorescence (DFA or IFA)

Differentiate type A and B

Sensitivity and specificity unknown

Cannot subtype with accuracy

Viral culture

elaborate


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Thermal scannersused

Infra red technology

The skin temperature ofpassengers is screened

Anyone with higher than normal

temperature are subjectedtofurther evaluation and ifneeded quarantined


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Treatment

(H1N1) influenza virus is sensitive (susceptible) to the neuraminidase inhibitor

antiviral medications, zanamivir and oseltamivir.It is resistant to the adamantane antiviral medications, amantadine and

rimantadine.

Antiviral Treatment for Novel (H1N1) Influenza

Oseltamavir, Zanamavir

Treatment is recommended for:

All hospitalized patients with confirmed, probable or suspected novelinfluenza (H1N1).

Patients who are at higher risk for seasonal influenza complications.

Age > 65, smokers, chronic ailments


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Treatment with zanamivir or oseltamivir to be initiated as soon as possibleafter the onset of symptoms.

Maximum benefits if treatment is initiated within 48 hrs

48 hrs reduces hspital stay and gives mrtality benefit

Duration of treatment 5 days


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Antiviral medication dosing recommendations for treatment or chemoprophylaxis of novel influenza A(H1N1) infection.

Agent, group Treatment Chemoprophylaxis

OseltamivirAdults 75-mg capsule twice per day for 5 days 75-mg capsule once dayChildren 12 months

15 kg or less 60 mg per day divided into 2 doses 30 mg once per day16-23 kg 90 mg per day divided into 2 doses 45 mg once per day24-40 kg 120 mg per day divided into 2 doses 60 mg once per day>40 kg 150 mg per day divided into 2 doses 75 mg once per day

Zanamivir

Adults Two 5-mg inhalations twice per day Two 5-mg inhalations once per day

Children Two 5-mg inhalations twice per day(age, 7 years or older) Two 5-mg inhalations (10 mg

total) once per day (age, 5 yearsor older)


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Is chemoprophylaxis indicated ????

Indications

A.Post exposure prophylaxis

1.Close contact with a person who is a confirmed, probable or suspected case of influenza A (H1N1)virus infection during the infectious period of the case.

infectious periodis defined as one day before until 7 days after the cases onset of illness

B.Pre exposure prophylaxis

1. Antiviral medications should be given during the potential exposure period and continued for 10days after the last known exposure to a person with (H1N1) influenza


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Oseltamivir and zanamivir are Pregnancy Category " medications,

- No clinical studies have been conducted to assess the safety of thesemedications for pregnant women.- Few adverse effects have been reported- Pregnancy should not be considered a contraindication to oseltamivir or

zanamivir use.- Because of its systemic activity, oseltamivir is preferred fortreatment of

pregnant women


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Thankyou

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