japanese encephalitis: case in odisha
TRANSCRIPT
JAPANESEENCEPHALITIS
SUBASH KUMAR PATRANEWSHREE ROUT3RD SEMESTERS.C.B. MEDICAL COLLEGECUTTACK
DR BIMOCH PROJNA PATYASSOCIATE PROFESSOR, DEPT. OF MICROBIOLOGYS.C.B. MEDICAL COLLEGECUTTACK
INTRODUCTION Japanese Encephalitis is an arboviral infection
of horses, pigs, birds and humans caused by mosquito borne Japanese Encephalitis Virus(JEV) Why the
name ARBO ???ARTHROPOD
BORNE
HISTORY 1871: 1st case of JE 1924: Great epidemic in Japan -6125 human cases, 3797 deaths 1930’s: JE vaccines first became available 1935: Virus first isolated -From a fatal human encephalitis case 1938: Virus first isolated from mosquito
GEOGRAPHICAL DISTRIBUTION
IndiaBangladeshPhilippinesPakistanChina
JapanSri LankaThailandVietnam
Republic of Korea
DISTRIBUTION IN INDIA Mainly in the rural
agricultural areas where flooding irrigation is practised
Transmission is usually during rainy season but can also occur all round the year in tropical areas
Highest incidence in states of:Uttar PradeshAssamBihar
ETIOLOGY
ABOUT THE VIRUS Caused by Arbo Virus CLASS
B Genus: Flavivirus Genome: ss RNA Mol. Weight: 3x106 Dalton Virion: spherical, lipoprotein
enveloped particles40-50nm in diameter3 structural and 7 non
structural proteins
RESISTANCE Temperature: Destroyed by
heating above 56oC for 30 minutes
pH: Inactivated in acidic environment pH 1-3
Survival: sensitive to UV light and gamma irradiation
TRANSMISSION
HOSTS AND VECTORS
Amplifying host: Pig Reservoir host: Ardeid birds (heron, erget) Incidental host: Human, horse, donkey Vector: Mosquito (Culex tritaeniorhynchus)
AMPLIFYING HOSTAn amplifying host is a host in which the level of pathogen can become high enough that a vector that feeds on it will probably become infectious.
PIGS
RESERVOIR HOSTA reservoir host can harbour a pathogen indefinitely with no ill effects
HERON ERGET
INCIDENTAL HOST
An incidental host is an intermediate host that generally does not allow transmission of the virus, thereby preventing the parasite from completing its development
They are also known as dead-end host.
HORSE HUMAN
VECTOR
• Culex tritaeniorhynchus is the chief mosquito vector for JE
• Wide host range• Oviposit in flooded fields• Active during twilight• Other species (ades,
anopheles, mansonia)
CULEX
ENVIRONMENT Flooded fields Fish ponds Rice paddy Ditches
I am so sick
PATHOGENESIS
Manifestation of various neuronal symptoms
Virus proliferates and damages the neuronal tissue
Virus is transported to brain via blood
After multiplication in R.E. system, viremia ensues
Virus enters the body through the bite of mosquito
CLINICAL FEATURESProdermal stage
Acute encephalitic stage
Late stage
Sequale
PRODERMAL STAGE Lasts for 1-6 days Fever, Rigor Headache GI problems Lethargy Malaise
ACUTE ENCEPHALITIC STAGE Convulsions Altered sensorium,
unconsciousness, coma Tremor Abnormal movement of
limbs Mask like face Stiff neck Muscular rigidity
LATE STAGE
Mental impairment Increased deep tendon
reflex Epilepsy Speech impairment Behaviour abnormalities
PATHOLOGICAL FEATURES Perivascular chronic
inflammation Microglial nodules Neuronophagia Neutrophilic
inflammatory filtrate
Bilateral Thalamic Hemorrhage
DIAGNOSIS AND TREATMENT
DIAGNOSIS History Brain tissue analysis CSF analysis: moderately
increased CSF protein Serological tests: JE specific IgM
TREATMENT No antiviral drug for JE
has been found yet Only supportive
treatment:Suction-oxygenIV fluids and mannitolAnti convulsionInj. Paracetamol
JENVAC JENVAC ® is a purified inactivated JE
vaccine Prepared at National Institute of
Virology, Pune 2 doses of 0.5 ml at 28 days interval Booster dose after 1 year
PREVENTION AND CONTROL
Sanitary prophylaxis
Medical prophylaxis
Agricultural practices
Animal reservoir
Vector control
SANITARY PROPHYLAXIS Housing of animals
indoors in screened stabling During JE outbreaks During peak vector
activity Aerial or ground
fogging with ULV insecticides
MEDICAL PROPHYLAXIS
Vaccination of humans, horses and pigs
Available under UIP in 112 endemic districts of India
Travellers are needed to take proper vaccination before visiting the south east Asian countries
AGRICULTURAL PRACTICES
Adopt water management practices of paddy cultivation by having a dry day in a week this will: Conserve water Reduce larval population Increase rice grain yield Reduce emission of methane
Using neem products as fertilizers.
ANIMAL RESERVOIR
Japanese encephalitis was controlled in Japan by vaccinating the pig population
All pig rearing practices must be undertaken away from human habitations
This kind of practice of pig husbandry must be promoted (bank loans)
VECTOR CONTROL Eliminate mosquito
breeding areas Adult and larva control:
ULV insecticides and PPM Cover all water containers,
wells, water storage tanks Use mosquito nets, coil
incenses mosquito repellents
Japanese EncephalitisIn ODISHA
CASE SENARIO IN ODISHA
Most affected district : Malkangiri 1st JE death – 8th Sept 2016 Death toll reached more than 130
Now Odisha has been added to the list of JE high burden state [23rd Nov 2016]
CAUSE
More faith in tantriks than doctors Low availability of doctor
No. of doctors Entire district District HQPresent 23 11Required 115 45
23
Entire District
11
District HQ
EXPERTS SPEAK… Dr John Jacob, CMC Vellore
suspected Cassia Occidentalis beans (bana chakunda) to be culprit
Case similar to Saharanpur, UP case of 2007 (81 deaths)
Vaccination drive started from 5 Dec 2016
REFERENCES