Yellow fever is caused by a flavivirus transmitted by Aedes aegypti mosquitoes. It occurs in tropical areas of Africa and South America, putting over 900 million people at risk. Each year there are approximately 200,000 cases and 30,000 deaths worldwide. The virus is maintained in non-human primates, and humans can be infected either through forest exposure or urban cycles involving humans and mosquitoes. Prevention focuses on vaccination and mosquito control to limit transmission between humans and mosquitoes.

3. YELLOWYELLOW
FEVERFEVER
SUJATA MOHAPATRA.SUJATA MOHAPATRA.

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

5. Disease BackgroundDisease Background
 First account ofFirst account of
sickness diagnosed assickness diagnosed as
YF occurred in 1648.YF occurred in 1648.
 Causative agent:Causative agent:
genus Flavivirus.genus Flavivirus.
 Vector: Aedes aegyptiVector: Aedes aegypti
(mosquito).(mosquito).
 Nonhuman primatesNonhuman primates
maintain disease.maintain disease.

6. Global DistributionGlobal Distribution
 In 45 countries ofIn 45 countries of
Africa & LatinAfrica & Latin
America.America.
 More than 900 millionMore than 900 million
people are at risk.people are at risk.
 200,000 cases &200,000 cases &
30,000 deaths30,000 deaths
worldwide each year.worldwide each year.

7. EPIDEMIOLOGYEPIDEMIOLOGY
Flavivirus FibricusFlavivirus Fibricus
ManMan
Forest(>24Forest(>2400
))
YELLOW
FEVER

8. AgentAgent
 Flavivirus FibricusFlavivirus Fibricus
 Group B ArbovirusGroup B Arbovirus

10. Reservoir & VectorReservoir & Vector
 MonkeyMonkey
 MosquitoMosquito

11. Host FactorHost Factor
 All ages & both sexesAll ages & both sexes
 Persons in contact withPersons in contact with
forests.forests.
 Wood cutters, Hunters.Wood cutters, Hunters.
 Immunity-Immunity- One attack ofOne attack of
yellow fever givesyellow fever gives
lifelonglifelong immunity.immunity.

12. 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, Immune***Includes: survivors, victims, Immune
Susceptible Exposed* Infective** Recovered***
Vaccinated

13. Environmental FactorEnvironmental Factor
 ClimateClimate
 Tropical with a relativeTropical with a relative
humidity.humidity.
 Endemic presence ofEndemic presence of
disease in the jungle.disease in the jungle.
 Social FactorsSocial Factors
 Urbanization,Urbanization,
 More Populated,More Populated,
 Forest.Forest.

14. INCUBATION PERIODINCUBATION PERIOD –– 3-6 days3-6 days
PERIOD OF COMMUNICABILITYPERIOD OF COMMUNICABILITY -- Blood ofBlood of
patients is infective during the first 3-4days.patients is infective during the first 3-4days.

15. Cycles of YFCycles of YF
TransmissionTransmission
MOSQUITO
MONKE
Y
HUMAN,
MONKE
Y
MOSQUIT
O
HUMAN HUMAN
MOSQUIT
O
MOSQUITO
MOSQUIT
O
MOSQUITO
Jungle Village City
www.who.int

16. Clinical featuresClinical features

17. Diagnosis &Diagnosis &
ManagementManagement
 Blood studiesBlood studies
 Supportive TreatmentSupportive Treatment
 IV FluidsIV Fluids
 AntipyreticsAntipyretics
 AntibioticsAntibiotics
 Use of Mosquito-net orUse of Mosquito-net or
mosquito repellents.mosquito repellents.

18. Prevention & ControlPrevention & Control
 17D17D Vaccine,Vaccine,
 SubcutaneouslySubcutaneously 0.5ml0.5ml,,
 Immunity begins to appear on theImmunity begins to appear on the77thth
day & lasts for more thanday & lasts for more than 35 years35 years..
 International Certificates.International Certificates.