Thursday, 3 November 2016

Perceive the disease #Japanese encephalitis


The world is wrecked by the recent outbreaks of #Dengue, #Chickengunya,# Zika  #Japanese encephalitis is the recent one  which is a hash tag in twitter #Malkangiri where toll rises to 80 due to this disease.

Japanese encephalitis is yet another similar viral disease transmitted by mosquitoes. This disease is mainly found in Asian countries like China, South Korea, Japan, Thailand, India, Nepal, Malaysia, Combodia, Myanmar and Vietnam.

Causative agent:

Japanese encephalitis virus E is the causative agent of this disease, this virus was formerly called as Japanese Encephalitis virus B. This Virus if from the virus family Flaviviridae whose name is obtained from yet another similar disease called as “yellow fever” which is caused by the viruses from the same family. As its name suggests it mainly affects brain- Encephalon.

 Transmission:


Animals; mainly pigs, birds, horses and cattle are the reservoirs of the virus, but the main  threat is from the transmitting agents- the mosquitos Culex tritaeniorhynchus and cules vishnui. These mosquitos transmit the virus from reservoirs to human host by their bites. This disease causes severe problems in human hosts.

Pathogenesis:

The Virus enters the human blood by mosquito bite and it reaches the Central nervous system (brain) by the travelling leukocytes mainly T-lymphocytes. Once, after crossing  blood brain barrier the virus particles bind to endothelial cells(cells within the interior of blood vessels) .The incubation period for the onset of the disease is 5-15 days; during this period the multiplies within the  T-Lymphocytes and endothelial cells of the central nervous system. When a virus infects a class of neuron (Brain) cells called astrocytes the disease is spread to other parts of the body. The rapid multiplication of virions inside the brain elicits an immune response which results in the release of Nitric oxide, which kills the neuronal cells along with virions and results in inflammation of meninges, this phenomenon is called as meningitis.

Along with NO immune response also produces tumor necrosis factor- TNF-alpha, which causes death of neuronal cells. Multiplication of virions and meningitis causes intake of reactive oxygen species inside the neuron (brain) cells which increase the complication involved in the diseases. This massive immune responses affects progenitor cells and their recycling, which causes severe damage to the brain in infected persons.

Symptoms
  • ·         Mild fever
  • ·         Headache
  • ·         Neck disorientation
  • ·         Coma
  • ·         Seizures
  • ·         Respiratory problems
  • ·         Permanent neurological problems such as memory, behavior
  • ·         Paralysis


Diagnosis
Antibody detection in the cerebro-spinal fluid and serum is the best diagnostic procedure, but there can be confusion in the conclusion due to onset of cross reaction with antibodies of other Flavi viruses. Modern ELISA and RT-PCR methods proved to be effective diagnostic approaches.

Treatment
  • ·         Interferon therapy
  •         Oral intake of arctigenin, rosmarinic acid.


Prevention and control
  • ·         Vaccination
  • ·         Controlling breeding of mosquitos, adopting pisciculture and traditional agriculture methods in water logged crops such as paddy and sugarcane.
  • ·         Using larvicides and insecticides in water logged areas.


Interesting facts
  • ·         Disease mainly occurs during rainy seasons and irrigational land where water logged crops like paddy are grown.
  • ·         These crops allow birds to prey larvae and hence leads to spread of diseases.
  • ·         Till now there are no drugs to treat this disease effectively
  • ·         Juice or extract of weed like burdock fruit is effective in combating the disease.
  • ·         Peppermint juice, rosema
    ry juice helps extensively.