Japanese Encephalitis (JE), a mosquito borne disease, is the leading cause of viral encephalitis in 14 Asian countries due to its epidemic potential, high case fatality rate and increased possibility of lifelong disability in patients who recover from this dreadful disease.
1.4 Magnitude of JE Problem in India
The Directorate of national vector borne disease control programme (NVBDCP)
is monitoring JE incidence in the country since 1978. The data on JE (NVBDCP)
show that a total 101,137 and 33,202 deaths (CFR 32.82 %) due to JE have been
reported in India since 1978 till 2007 (P) from all over the country. The annual
reported incidence for the country has ranged from 1,243 to 7,500. In the year
1978, JE cases were reported from 21 states/union territories. In spite of seriousness of the disease, still only few books are available for ready reference. Hence, this book will be useful for students, entomologists, paramedical staff and vector control managers in public health. Of the thousand suspected JE deaths in India annually, more than 75% is contributed by Northern India wherein disease transmission failed to be explained based on entomological evidence due to inadequate mosquito surveillance tool used in determining JE vector density. In order to overcome the above problem, Dr Bina Pani Das, the author of this book, developed “BPD hop cage method”, a simple, cost effective, and operationally feasible surveillance tool specially designed to capture predominantly day resting
adult Culex. tritaeniorhynchus mosquitoes, the principal JE vector species in the country from land and aquatic vegetation.
The disease was first recognised in 1955
and since then many major out-breaks have been reported from different parts of
the country, predominantly in rural areas. Case fatality rate has ranged from 10
to 77.5 % and in patients who recover;
Health including control of mosquito borne diseases is a state subject.
Entomological man power and set-up available with the state authorities areeither very poor or does not exist.
We should remove health from state list to central list at least when the parts where disease control does not stop at state boundaries
JE endemic
areas in Karnal district (Haryana) and Saharanpur district (Uttar Pradesh).
Though JE virus cannot be eliminated from the environment, as it is not possible
to kill all the infected reservoir birds; however, the disease burden can certainly
be reduced appreciably by efficient assessment of JE vector abundance
and JE virus infection in local vector mosquitoes.
“Microbial control agent for mosquito vector
of human diseases”
Bina Pani das writes (you can get her book by clicking on the link)
A prime requisite for this is
the accurate determination of the species of Culex mosquitoes actually involved
in transmitting the disease. The only available key can be used by those familiar
with taxonomic language and not by common users in the programme. I present
here a simple illustrated key, in a language which is tuned to the medical officers
and paramedical staff in public health programme, to differentiate 17 commonly
encountered species of Culex (Culex) mosquitoes associated with JE in India.
Though JE virus cannot be eliminated from the environment, as it is not possible
to kill all the infected reservoir birds; however, the disease burden can certainly
be reduced appreciably by efficient assessment of JE vector abundance
and JE virus infection in local vector mosquitoes. A prime requisite for this is
the accurate determination of the species of Culex mosquitoes actually involved
in transmitting the disease. The only available key can be used by those familiar
with taxonomic language and not by common users in the programme. I present
here a simple illustrated key, in a language which is tuned to the medical officers
and paramedical staff in public health programme, to differentiate 17 commonly
encountered species of Culex (Culex) mosquitoes associated with JE in India.
The objective of the book is to disseminate the knowledge gained by me over
a period of nearly last 15 years of research in the field of ecology of mosquito
vectors of JE virus from Northern India to anyone who wishes to curtail death of
children due to this dreaded disease.
So the question is what is Centre for Medical
Entomology & Vector Control, National Centre for Disease Control (formerly
NICD) doing ? Or for that matter the UP health department doing ?
how many of theses children had the following tests done ?
- Enzyme-linked immunosorbent assay (ELISA) for anti-Japanese encephalitis IgM performed on cerebrospinal fluid or serum
- Definitive diagnosis requires fourfold increase in virus-specific IgG confirmed by plaque reduction neutralization assay
why is it we are not able to find a way to curtail transmission of this deadly disease.
is the present epidemic really Japaneses encephalitis?
AES Acute Encephalitis Syndrome
ATCC American Type Culture Collection
BPD Bina Pani Das
CFR Case fatality rate
CIF Central instrumentation facility
CRME Centre for Research in Medical Entomology
CSF Cerebro spinal fluid
DC Dusk collection
DST Department of Science and Technology
EIA Enzyme immuno assay
ELISA Enzyme linked immuno sorbent assay
HC Hand collection
IDA International Depositary Authority
IgG Immunoglobulin G
IgM Immunoglobulin M
JE Japanese Encephalitis
JEV Japanese Encephalitis Virus
JMI Jamia Millia Islamia
MRC Malaria Research Centre
NCDC National Centre for Disease Control
NICD National Institute of Communicable Diseases
NIMR National Institute of Malaria Research
NIV National Institute of Virology
NVBDCP National Vector Borne Disease Control Programme
PMH Per man hour
PMHD Per man hour density
PRD Per room density
PTHC Per ten hop cages
WHO World Health Organization
1.5 JE Outbreaks in India
One of the most disturbing features of JE in India has been the regular occurrence
of outbreaks in different parts of the country. Almost every year, so-called
“undiagnosed viral illness” invades India and unfailingly claims thousands of lives
especially in children below 15 years. JE is claimed to be the leading cause in
these episodes as it is the only disease causing viral encephalitis in India.
Kerala state in south India experienced its first outbreak in 1996, Haryana
in 1990, and Uttaranchal, third state from Northern India, as recently as 2006
with 58 cases and 21 deaths. The worst ever recorded JE outbreak in India was
reported from UP in 2005 when 6,061 cases with 1,500 deaths (CFR 24.7 %)
were recorded from the state (Table 1.1). Significantly, higher CFR has been
found during outbreaks, the highest reported being 84.8 % during 2005 outbreak
in Haryana. Districts worst affected by outbreaks of Acute Encephalitis Syndrome
(AES)/JE in terms of morbidity, mortality and frequency of occurrence are given
in Table 1.2. Gorakhpur and Deoria districts of Uttar Pradesh have reported maximum
number of outbreaks so far. Although, primarily reported from rural agricultural
areas, outbreaks have been reported from peri-urban areas also. The
outbreaks are closely associated with monsoon, agricultural practice, presence of
vector mosquito species and reservoir hosts.
The incidence of JE is recorded mainly among poorer people in villages
where pig rearing is practiced. Cattle and buffaloes are preferred host for
the mosquitoes, but they do not circulate the virus and therefore they do not play a
role in its maintenance and spread, but act as “dampers” in the cycle. Man, is only
occasionally infected and is a “dead end”, since viraemia in human blood is too
low and transient to infect mosquitoes. The disease occurs in human population
when environmental conditions are favourable for prolific mosquito breeding as in
monsoon and post monsoon season. The disease is mainly prevalent in rural areas
among the lower socio-economic group of the population.
Quick Medical Diagnosis & Treatment 2019
Encephalitis, Japanese
Key Features
Essentials of Diagnosis
- Most important vaccine-preventable cause of encephalitis in the Asia-Pacific region
- The virus is transmitted by mosquitoes, especially Culex species
- Wide symptom spectrum; most infections asymptomatic
General Considerations
- Most common cause of encephalitis in East Asia with over 68,000 estimated annual cases
- Most cases occur in the summer and late fall although in tropical and subtropical areas transmission occurs throughout the year
- Major outbreaks every 2-15 years often correlate with patterns of agricultural development
- Virus is transmitted by mosquitoes, especially Culex species
- Wading birds and pigs more commonly sustain the infection as reservoirs; viremia in humans is transient and not usually high enough to sustain transmission
- In endemic countries, Japanese encephalitis is primarily a disease of children
- Travelers to major urban areas for < 1 month are at minimal risk
Clinical Findings
Symptoms and Signs
- Incubation is 5–15 days
- Most persons asymptomatically seroconvert
- Sudden onset headaches and nausea and vomiting followed by
- Mental status changes
- Parkinsonian movement disorders
- Seizures, typically in children
Differential Diagnosis
- St Louis encephalitis
- West Nile encephalitis
Diagnosis
Laboratory Findings
- Leukocytosis
- Mild anemia
- Hyponatremia
- Cerebrospinal fluid typically shows
- Mild to moderate pleocytosis with a lymphocytic predominance
- Slightly elevated protein
- Normal glucose
- Enzyme-linked immunosorbent assay (ELISA) for anti-Japanese encephalitis IgM performed on cerebrospinal fluid or serum
- Definitive diagnosis requires fourfold increase in virus-specific IgG confirmed by plaque reduction neutralization assay
Imaging
- In severe disease, brain imaging reveals thalamic lesions, with the hippocampus, midbrain, basal ganglia, and cerebral cortex affected to varying degrees
Treatment
- Supportive, including antipyretics, analgesics, bedrest, and fluids
Outcome
Complications
- Cognitive, neurologic, and psychiatric complications, including memory and intellectual impairment, occur in as many as 50% of survivors and persist at least 1–2 years after acute infection
Prevention
- Use of mosquito repellents
- Wearing long sleeves, long pants, and socks
- Use of air-conditioned facilities and bed nets are essential means of protection
- Four effective types of vaccine against Japanese encephalitis are available worldwide, including live attenuated and inactivated vaccines
- In the United States, inactivated Vero-cell culture-derived Japanese encephalitis vaccine (IXIARO) is licensed for the prevention of Japanese encephalitis in persons 2 months of age and older
- No studies about its safety in pregnant women
- Therefore, administration to pregnant women should be deferred, unless the risk of infection outweighs the risk of vaccine complications
- Primary vaccination requires two doses administered 28 days apart, to be completed more than 1 week before travel
- For adults, a booster dose is recommended in case of potential reexposure or of continued risk for infection if the primary series of the vaccine was administered over a 1 year before
- Travelers who plan to spend more than 1 month in rural East Asia during Japanese encephalitis virus transmission season should receive the vaccine
- The risk of serious reactions, including potential encephalitis, with live vaccines, is very low
Prognosis
- Mortality is as high as 30%
References
Heffelfinger JD, et al. Japanese encephalitis surveillance and immunization—Asia and Western Pacific regions, 2016. MMWR Morb Mortal Wkly Rep. 2017 Jun 9;66(22):579–83.
[PubMed: 28594790]
[PubMed: 28594790]
Hills SL, et al. Japanese encephalitis. In: Centers for Disease Control and Prevention. Chapter 3 (83): Infectious Diseases Related to Travel. CDC Health Information for International Travel 2018. New York: Oxford University Press, 2018. https://wwwnc.cdc.gov/travel/yellowbook/2018/infectious-diseases-related-to-travel/japanese-encephalitis
Sunwoo JS, et al. Clinical characteristics of severe Japanese encephalitis: a case series from South Korea. Am J Trop Med Hyg. 2017 Aug;97(2):369–75.
[PubMed: 28829730]
[PubMed: 28829730]
World Health Organization. Japanese encephalitis: fact sheet No. 386. December 2015. http://www.who.int/mediacentre/factsheets/fs386/en/
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