Ecological

Transmission of Japanese encephalitis

Japanese Encephalitis is a Flavivirdae, single stranded, enveloped RNA virus that are commonly found and transmitted in mosquitos and ticks.  The Transmission of JE is very common to other mosquito spread viruses in the way that it takes two different occasions in order to spread because the virus needs to multiple in a host. 

• Mosquitos (Culex tritaeniorhynchus) are the vectors that transmit the virus.
• Mature pigs are the main reservoir hosts however, birds can also serve as well. 
• Mosquitos will infect the pig allow the virus to grow and to become stronger.
• Then the vector will take the blood from the pig containing the replicated virus and will now be  able to spread to other species.

Spreading of the Virus

The spreading of this virus is what makes this disease so deadly.  As stated above, mosquitos are the way this virus is transferred from species to species.  Mosquito bites can not be avoided no matter how much precautionary steps are taken. Once mosquitos are able to reproduce at a high rate this disease has the capability to spread to urban areas.

• This virus is started in agricultural areas in wet rural areas mostly near standing water.
• Often near rice farms and often breed in rice paddies or farms containing large amount of livestock.
• Although this is found mostly in rural areas, flooding and excessive rain in summer months allow for Culex tritaeniorhynchus to breed and to expand it's radius into urban areas which opposes a great threat to humans and 
• Boars are able to transfer the virus through sexual intercourse.  
• Lizard and bats are sometimes able to obtain JE from eating mosquitos however, they show no symptoms.

What species are commonly affected by Japanese encephalitis?

Being affected with this virus does not mean an animal needs to show symptoms, in fact, most animals do not show any symptoms at all.  However, the when a species is showing symptoms it is often too later as the species has been affected with the virus for at least 12-14 days.  Humans can be infected with the virus especially without the proper vaccinations and when traveling to Asia people to not always obtain proper vaccination in order to reduce their chance.  Therefor, allowing the possibility of obtaining the virus. 

• Pigs are most commonly affected and can experience still births, abortions, mummies, fits and convulsions infertility and swelling of the brain.  
• Horses most of the time do not show side effects however, can experience fever, inability to walk, teeth grinding and swelling of the brain.
• Humans intially have fever, headache and vomiting can lead to seizures and eventually swelling of the brain.  
• Species such as birds, cats, dogs, cattle and most other mammals do not show any symptoms of having the illness.
• Although a species does not show symptoms, this does not mean they are not able to continue to transfer the disease by a vector. 

Dead End Host

 

Dead end host play a huge role in Japanese Encephalitis.  It is very scary to think of the possibility of this disease spreading from species to species not requiring a vector.  If this were the case it is not crazy to think, with a known cure, that pigs and horses would not be able to survive in large areas of Culex tritaeniorhynchus.

• A dead end host is an animal who does not transmit the virus to another species.
• Cattle, sheep, mammals, reptiles are all dead end hosts.
• Luckily, humans are also dead end hosts which allows a sense on control when JE comes to urban populated areas.

Controlling Japanese Encephalitis

• Vaccinating pigs and horses is the best way to prevent an outbreak in the area.  
• Vaccinations do not always prevent the disease but it has be proven to dramatically reduce the symptoms. 
• Vaccines do not completely prevent the chance of an outbreak due to the amount of wild birds that could also serve and reservoir hosts.
• Mosquito repellent and not leaving unnecessary standing waters are ways of controlling the mosquito population around agricultural areas.  

In conclusion, Japanese encephalitis is disease in which people in Asia are well aware of and have taken the appropriate steps in order to prevent coming down with the virus.  However, for our worst-case scenario we went into the possibility of this being used in war.  Because people in the United States are often unaware of this disease it is crucial to make them away if traveling to Asia or if an outbreak starts to happen.  Controlling the disease is the only way we can prevent this from becoming an epidemic.  With mosquito control and proper vaccination when needed, Japanese Encephalitis can stay as a local rural virus in Asian countries.  However, this does not mean that we should not continue to look for possible cures. 

Integration

            Japanese Encephalitis is a very deadly disease, which is commonly found in areas without many people which makes it often seem like an after thought when it comes to being prepared.  Vaccinations are made for humans and are very effective when it comes to minimizing the symptoms.  The mortality rate for Japanese Encephalitis is 25%.  If one is lucky enough to survive there is a very high chance they will suffer severe brain damage,  In countries in Asia people are well aware of the vaccinations that are accessible and do get vaccinated, however, the problem could occur when traveling tourist are unaware of the risk that JE could oppose to them. 

             Molecularly we went into what kind of virus is Japanese encephalitis and how it affects the RNA.  We went into the genetic make up of the Japanese encephalitis and its characteristics.  Japanese Encephalitis enters through the clathrin mediated endocytosis and then it is able to bind to a specific receptor and than able to affect the body.  However, I believe the most important part of this section was to go into the possible treatments.  Although there is no known cure and prevention and vaccination is by far the better option scientist are working in order to find a cure.  We went into the different options regarding lipid rafts and disrupting the raft composition.

Next in the Organismal section we went into the mosquito responsible for being the vector of this virus (Culex tritaeniorhynchus).  Japanese encephiltis is a zoonotic disease meaning that it comes from an animal and affects humans.  These are tough to control because vaccinating animals is not always an option especially when it comes to wild animals.  We went into the different types of hosts and talked about the difference between reservoir and incidental hosts.  The most important part of this section is the part about the increased risk factors and the activites that could make a person more prone to obtaining the disease.

The ecology section we really want to focus on the affects on different animals.  We first went into how exactly Japanese encephalitis is transmitted from species to species.  We went into the spreading of the disease and how this virus is found in rural areas near rice farms and standing water.  We talked about the risk that flooding and increased mosquito population could allow the radius of this virus to grow into urban areas.  We went into the most common species affected and how they were affected.  There are differences between a non dead end host getting affected and a dead end host being affected and those were looked into.  The most important part of this section is the way to prevent this from spreading through difference types of species.  It is very difficult because wild birds can be serve as hosts.  However, with proper mosquito control around farms, we can do our best to make sure there is not an outbreak. 

The public health page started by giving statistics and explained the importance of knowledge of this disease.  It was made very clear how 3 billion people are at risk of this disease.  There are four main types of vaccinations: Inactivated Mouse Brian-Based Vaccines, inactivated Cell-Based Vaccines, Live Attenuated Vaccines and Live chimeric Vaccines.  We went into the different types of injections and when a person in Asia receives the vaccine.  Safety is the most important aspect of this section and this section concluded with ways to ensure that and also The Ten Step Bioterrorism Outbreak Protocol by the CDC.