Yellow Fever 2.pptx

7/25/2019 Yellow Fever 2.pptx

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Diseases Carried by Insects


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Communicable Period

The time during which an infectious agent

may be transferred directly or indirectly

from an infected person to anotherperson, from an infected animal to

humans, or from an infected person to

animals, including arthropods


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Communicable Period

The time during which the patient is

infectious to others


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Incubation Period

The time interval between initial contact

with an infectious agent and the first

appearance of symptoms associated with

the infection.


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Incubation Period

In a vector, it is the time between entrance

of an organism into the vector and the

time when that vector can transmit the

infection (extrinsic incubation period.


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!uarantine

"eparating and restricting the movement

of well persons who may have been

exposed to a communicable disease to

see if they become ill


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Isolation

"eparation of ill persons who have a

communicable disease from those who

are healthy


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#$%%&' $)$*


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Introduction

#ellow fever is a viral disease, found in

tropical regions of +frica and the +mericas

It principally affects humans and

moneys, and is transmitted via the bite of

Aedesmos-uitoes


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Introduction

There are //,/// estimated cases of

yellow fever (with 0/,/// deaths per year


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Incubation Period

Three to six days


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1&T

The virus is carried from one animal to

another (hori2ontal transmission by a

biting mos-uito (the vector. The mos-uito

can also pass the virus via infected eggs

to its offspring (vertical transmission

There are three types of transmission

cycle3 Sylvatic, Intermediate, Urban


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"ylvatic #ellow ever

Sylvatic(or 4ungle yellow fever occurs intropical rainforests

"ylvatic 1os-uitoes moneys

virus onto other mos-uitoes that feed onthem infect humans entering theforest

This produces sporadic cases, thema4ority of which are often young menworing in the forest e.g. logging


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Intermediate Cycle &f #ellow ever

"mall5scale epidemics in rural villages

Increased contact between man and

infected mos-uito leads to disease

This is the most common type of outbrea

seen in recent decades in +frica


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6rban #ellow ever

*esults in large explosive epidemics when

travelers from rural areas introduce the

virus into areas with high humanpopulation density. Domestic mos-uitoes,

most notably Aedes Aegypti, carry the

virus from person to person.


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"igns 7 "ymptoms

+cute Phase3

ever

1uscle pain (with prominent bacache

8eadache

"hivers

%oss of appetite

9ausea and:or vomiting

+fter three to four days most patientsimprove and their symptoms disappear


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"igns 7 "ymptoms

;toxic phase> within ? hours

ever reappear

@aundice and complains of abdominalpain with vomiting

Aleeding can occur from the mouth, nose,

eyes and:or stomach


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"igns 7 "ymptoms

Alood appears in the vomit and faeces.

Bidney failure

8alf of the patients in the >toxic phase> die

within ;/5;? days. The remainder recover

without significant organ damage


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Prevention

+dministering yellow fever vaccineas

part of routine infant immuni2ation

Preventing outbreas in high5ris areasthrough mass >catch5up> campaigns

Control of Aedes aegypti in urban

centres


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Prevention

#ellow fever vaccine is safe and highly

effective. The protective effect (immunity

occurs within one wee in


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Type of vaccine

No. of dosesSchedule

Booster

Contraindications

Adversereactions

Special

precautions

Live viral

One dose of 0.5 ml subcutaneouslyoutine immuni!ation "ith measles vaccine at nine

months of a#e

$nternational health re#ulations re%uire a booster

every &0 years

'## aller#y( immune deficiency from medication or

disease( symptomatic )$* infection(hypersensitivity to previous dose( pre#nancy+

)ypersensitivity to e##( rarely, encephalitis in the

very youn#( hepatic failure. are reports of deathfrom massive or#an failure -see above.

/o not #ive before si months of a#e( avoid durin#

pre#nancy


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*eceptive +rea3 an area in which yellow

fever does not exist but where conditions

would permit its development if introduced

+edes +egypti Index3 the percentage ofhouses and their premises in a limited well

defined area showing actual breeding of

aedes aegypti larvae

Yellow Fever 2.pptx

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