YELLOW FEVERYELLOW FEVER

SUJATA MOHAPATRA.SUJATA MOHAPATRA.

OUTLINEOUTLINE

IntroductionIntroduction Disease BackgroundDisease Background DistributionDistribution EpidemiologyEpidemiology TransmissionTransmission Diagnosis & managementDiagnosis & management Prevention and ControlPrevention and Control Actions to TakeActions to Take

Disease BackgroundDisease Background

First account of First account of sickness diagnosed sickness diagnosed as YF occurred in as YF occurred in 1648.1648.

Causative agent: Causative agent: genus Flavivirus.genus Flavivirus.

Vector: Aedes Vector: Aedes aegypti (mosquito).aegypti (mosquito).

Nonhuman primates Nonhuman primates maintain disease.maintain disease.

Global DistributionGlobal Distribution

In 45 countries of In 45 countries of Africa & Latin Africa & Latin America.America.

More than 900 More than 900 million people are million people are at risk.at risk.

200,000 cases & 200,000 cases & 30,000 deaths 30,000 deaths worldwide each worldwide each year.year.

EPIDEMIOLOGYEPIDEMIOLOGYFlavivirus FibricusFlavivirus Fibricus

Man Man Forest(>24Forest(>2400))

YELLOW FEVER

AgentAgent

Flavivirus FibricusFlavivirus Fibricus Group B ArbovirusGroup B Arbovirus

Reservoir & VectorReservoir & Vector

MonkeyMonkey MosquitoMosquito

Host FactorHost Factor

All ages & both sexesAll ages & both sexes Persons in contact Persons in contact

with with forests.forests. Wood cutters, Wood cutters,

Hunters.Hunters. Immunity-Immunity- One attack One attack

of yellow fever gives of yellow fever gives lifelonglifelong immunity. immunity.

The SEVIR ModelThe SEVIR Model

Humans can be in one of five categories at a time.

*Virus incubating*Virus incubating**Contagious**Contagious***Includes: survivors, victims, ***Includes: survivors, victims, ImmuneImmune

Susceptible Exposed* Infective** Recovered***

Vaccinated

Environmental FactorEnvironmental Factor

ClimateClimate Tropical with a relative Tropical with a relative

humidity.humidity. Endemic presence of Endemic presence of

disease in the jungle.disease in the jungle. Social FactorsSocial Factors Urbanization,Urbanization, More Populated,More Populated, Forest. Forest.

INCUBATION PERIOD INCUBATION PERIOD – – 3-6 days3-6 days

PERIOD OF COMMUNICABILITY PERIOD OF COMMUNICABILITY - - Blood of Blood of patients is infective during the first 3-patients is infective during the first 3-4days.4days.

Cycles of YF Cycles of YF TransmissionTransmission

MOSQUITO

MONKEY

HUMAN,

MONKEY

MOSQUITO

HUMAN HUMAN

MOSQUITO

MOSQUITO

MOSQUITO

MOSQUITO

Jungle Village City

www.who.int

Clinical featuresClinical features

Diagnosis & Diagnosis & ManagementManagement

Blood studiesBlood studies Supportive TreatmentSupportive Treatment IV FluidsIV Fluids AntipyreticsAntipyretics AntibioticsAntibiotics Use of Mosquito-net or Use of Mosquito-net or

mosquito repellents.mosquito repellents.

Prevention & ControlPrevention & Control

17D 17D Vaccine,Vaccine, Subcutaneously Subcutaneously 0.5ml0.5ml,, Immunity begins to appear on Immunity begins to appear on

thethe77thth day & lasts for more than day & lasts for more than 35 years35 years..

International Certificates.International Certificates.