Influenza Proj

8/8/2019 Influenza Proj

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+Influenza

What is Influenza?

Also known as the Flu or Grippe

Viral infection-highly contagious

Who gets Influenza? Outbreaks throughout the world

Usually the winter

Infection caused by a virus Infects the respiratory tract


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+The Influenza Virus- Orthomyxoviridae

Viral family- Orthomyxoviridae

Enveloped

RNA Virus

Hemagglutinin (H): lectin responsible for the binding and

fusion of the virus to the host cell.

Neuraminidase (N):enzyme responsible for release of

offspring virus from infected cells


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+


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Influenza Virus Entry

Viral infection of the

respiratory tract

Spreads t

hroug

hth

e upperrespiratory tract and

sometimes invades the

lungs.


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+Types of Influenza

Three types of causes:

Type A- affects a variety of animal species

Type B- affects mainly humans

Type C- generally nonsymptomatic, is of little

medical concern


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+Type A

Also known as Avian Influenza

Subtype H5N1

Zoonotic Disease:Primarily infects birds

Birds are the reservoir

A does NOT stand for Avian


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+How it spreads from birds?

Originates from new breeding methods

Farmers do not want to waste food

In contact with:

Fecal matter

Saliva

Nasal discharge

Dirt


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+Type B

Usually found only in humans

Most common in young children and the elderly

Causes less severe epidemics than Type A


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+Variants of Flu Virus

The main variants are:

Bird flu (H5N1)

Human Flu

Swine Flu

Horse Flu

Dog Flu


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+I thought I was immune.

Antigenic Shift and DriftType A Antigenic Shift Abrupt change in the hemagglutinin and the neuraminidase

proteins

New subtype of the virus emerges

Antigenic Drift Series of mutations occurring over time, causes a gradual evolution

of the virus

Type A viruses undergoes both Antigenic Shift andDrift

Type B undergoes only Antigenic Drift


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+How does the flu spread?

Passed either directly or indirectly from person to person

Highly contagious

Found in body fluids (saliva and mucous)

airborne- droplets

small particles from cough or sneeze.

Virus enters through the nose or throat.


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+Think You Have the Flu?

Symptoms

Usually 1-4 days to develop symptoms

Chills 1st sign of virus

Fever usually during the 1st few days

(102 r to 103r F)

Signs: Fever Aches Chills Tiredness S

udden symptoms Headaches, Body aches and pains Weakness Nausea, vomiting, or diarrhea

Cough, sore throat, runny or stuffy nose


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+Secondary Infections

Severe Signs:

High fever

Chest pains

Cough with thick yellow mucous

Bacterial Pneumonia

Encephalitis (infection of the brain)

Bronchitis

Sinus infections

Ear infections

Heart and lung failure


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+Impact of Flu

Financial Impact

Hospital visits,health care costs rising

economic burden

Society Impact

Lost of work days

Lost of school days

Social complications/consequences


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+

What

Time of Year Is the Flu MoreCommon?

Usually begins when cold weather appears

Outbreaks:

Temperate zones- late fall and peak in mid- to late winter

Tropical zones- year-round isolation of the virus

In United States:

Between October and May

Peak between late December and March


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+Incidence

Approx. 25-50 million people get influenza each year

10,000 people in the U.S.

Leads to 150,000 in hospitalization

30,000 to 40,000 deaths each year.

Seasonal epidemics in winter

Cold and dry weather

Greater amount of time spentindoors


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+High risks:

People over 65

Children between 6 months and 2 years

Women during 2nd or 3rd trimester

People who have asthma or lung problems

Weakened immune system

Chronic heart conditions

Lung or kidney problemsDiabetes


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+Primary Level of Preventions

Educate people

Keep distance

Avoid people who are getting sick

Dont spread the germs

Wash your hands frequently

Cover your mouth and nose when coughing or sneezing

Stay home if you are getting sick

Enforce immunizations

Influenza vaccine- The flu shot

Protect you against strains of the virus


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+FYI:

Many influenza epidemics

begins in Asia

Close relationship between human and animal populations in rural China.

Workers work on or near farms with pigs and chickens

spread between species causes an epidemic.


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Influenza Proj