Causes of Japanese encephalitis
Primary Cause of Japanese encephalitis
The primary cause of Japanese encephalitis is the result:
Japanese encephalitis Causes: Risk Factors
The following conditions have been cited in various
sources as potentially causal risk factors
related to Japanese encephalitis:
Japanese encephalitis: Related Medical Conditions
To research the causes of Japanese encephalitis, consider researching the causes of these
these diseases that may be similar, or associated with Japanese encephalitis:
Japanese encephalitis: Causes and Types
Causes of Broader Categories of Japanese encephalitis: Review the causal information about the various more general categories of medical conditions:
What causes Japanese encephalitis?
Causes: Japanese encephalitis:
Questions and Answers About Japanese Encephalitis: DVBID (Excerpt)
By the bite of mosquitoes infected with the Japanese encephalitis
virus. (Source: excerpt from Questions and Answers About Japanese Encephalitis: DVBID)
Japanese Encephalitis Fact Sheet: DVBID (Excerpt)
Japanese encephalitis
(JE) virus: flavivirus antigenically related to St. Louis encephalitis
virus (Source: excerpt from Japanese Encephalitis Fact Sheet: DVBID)
Article excerpts about the
causes of Japanese encephalitis:
Information on Aedes japonicus: DVBID (Excerpt)
Aedes japonicus is an Asian species of mosquito generally found in Japan,
Korea, the Ryukyu Archipelago (Okinawa and associated islands), Taiwan, South
China, and Hong Kong. In 1998, the subspecies Aedes japonicus japonicus
was first detected in the United States
in New York and New Jersey. Since that time, Aedes japonicus has been
found in six other states: Ohio, Maryland, Connecticut, Massachusetts,
Pennsylvania, and Virginia. (Source: excerpt from Information on Aedes japonicus: DVBID)
Information on Aedes japonicus: DVBID (Excerpt)
Larvae are found in a wide variety of natural and artificial containers,
including rock holes and used tires. Preferred sites usually are shaded and
contain water rich in organic matter. The similarity of breeding habitats used
by Aedes japonicus to those of other Aedes species suggests that
the transport of eggs, larvae, and pupae in used tires may be an important
mechanism for introducing the species into previously uninfested areas. Eggs are
resistant to desiccation and can survive several weeks or months under dry
conditions. Aedes japonicus overwinters as eggs in the more northern
parts of its range. However, it is found throughout the winter as larvae as far
north as Tokyo (37° N), which is equal in latitude
to Norfolk, Virginia. (Source: excerpt from Information on Aedes japonicus: DVBID)
Information on Aedes japonicus: DVBID (Excerpt)
Although few studies have been done to assess the public and veterinary
health importance of Aedes japonicus, this species is suspected of being
a vector of Japanese encephalitis (JE) virus to swine in northern Japan. Under
experimental conditions it has been shown to transmit JE virus to mice and also
to transmit the virus to its progeny through the eggs. Unpublished studies
conducted at the United States Army Medical Research Institute of Infectious
Diseases in Fort Detrick, MD, indicate that Aedes japonicus is also a
competent experimental vector of West Nile virus, a flavivirus closely related
to JE and St. Louis encephalitis viruses. (Source: excerpt from Information on Aedes japonicus: DVBID)
Questions and Answers About Japanese Encephalitis: DVBID (Excerpt)
By rice field breeding mosquitoes (primarily the Culex tritaeniorhynchus
group) that become infected with Japanese encephalitis virus (a flavivirus
antigenically related to St. Louis encephalitis virus). (Source: excerpt from Questions and Answers About Japanese Encephalitis: DVBID)
Questions and Answers About Japanese Encephalitis: DVBID (Excerpt)
Japanese encephalitis outbreaks are usually circumscribed and
do not cover large areas. They usually do not last more than a couple
of months, dying out after the majority of the pig amplifying hosts have
become infected. Birds are the natural hosts for Japanese encephalitis.
Epidemics occur when the virus is brought into the peridomestic environment
by mosquito bridge vectors where there are pigs, which serve as amplification
hosts, infecting more mosquitoes which then may infect humans. Countries
which have had major epidemics in the past, but which have controlled
the disease primarily by vaccination, include China, Korea, Japan, Taiwan
and Thailand. Other countries that still have periodic epidemics include
Viet Nam, Cambodia, Myanmar, India, Nepal, and Malaysia. (Source: excerpt from Questions and Answers About Japanese Encephalitis: DVBID)
West Nile Virus Virology: DVBID (Excerpt)
All flaviviruses (e.g.,
West Nile [shown here], St. Louis encephalitis, dengue, Japanese encephalitis,
tick-borne encephalitis, yellow fever, etc.) share a common size (40-60nm),
symmetry (enveloped, icosahedral nucleocapsid), nucleic acid (positive-sense,
single stranded RNA approximately 10,000-11,000 bases), and appearance
in the electron microscope. Therefore, images of West Nile virus are representative
for this group of viruses. (Source: excerpt from West Nile Virus Virology: DVBID)
Related information on causes of Japanese encephalitis:
As with all medical conditions,
there may be many causal factors.
Further relevant information on causes of Japanese encephalitis may be found in: