Introduction
Japanese Encephalitis (JE) is a viral mosquito-borne infectious disease caused by the Japanese Encephalitis Virus (JEV). The Japanese Encephalitis Virus (JEV) is a flavivirus. The Japanese Encephalitis Viral disease does not transmit from human to human. Instead, the bite from the Culex tritaeniorhynchus mosquito causes JE in humans, which the mosquito transmits from pigs or water birds into the human body. Humans are dead-end hosts for the encephalitis virus.
The viral Japanese Encephalitis (JE) infection can affect people of any age, but it is most common in children. The disease follows one of two epidemiological patterns. According to one trend, the infection spreads in north Asian temperate climes in May or June and ends in September or October. The disease is year-round endemic in southern tropical locations in the second pattern. Adults in endemic areas have a natural immunity to JEV if they have previously been infected with the virus.
The incubation period for JEV infection is around four to fourteen days. Patients infected usually have the symptoms of mild fever and headache. Similarly, children may experience pain in the stomach, seizures, and vomiting. The symptoms during the severe stage include severe fever, neck stiffness, seizures, spastic paralysis, coma, and finally, death.
Thus patients should report to a physician for diagnosis and palliative care if they experience any of the above symptoms. How does a doctor diagnose this disease? How is Japanese Encephalitis treated? This article deals with a brief overview of Japanese Encephalitis’s diagnosis, management, and prevention.
Diagnosis of Japanese Encephalitis
When a patient visits a physician with the symptoms of Japanese Encephalitis, the physician usually tries to know the patient’s travel history or residence details. People who live in regions high in cases of Japanese Encephalitis have higher chances of being a suspect of Japanese Encephalitis if they experience any symptoms of the disease.
After getting the details about the patient, the physician carries out a laboratory test to identify if the symptoms represent Japanese Encephalitis or any other secondary type of Encephalitis. Before the 1980s, the haemagglutination inhibition test was utilized for many years, but it had several practical limitations and could not provide an early diagnosis because it required paired serum. During the 1980s, ELISAs were developed that captured the presence of IgG and IgM antibodies, and these ELISA have become the accepted standard for diagnosing Japanese Encephalitis.
The laboratory test is carried out to determine the presence of Japanese Encephalitis Virus-specific IgM antibody. In addition, the World Health Organization advises using an IgM-capture ELISA to perform the Japanese Encephalitis Virus-specific laboratory test in a single sample of cerebrospinal fluid (CSF) or serum. First, the physician collects the cerebrospinal fluid through a lumbar puncture or spinal tap. The rationale is that it reduces false-positivity rates from previous infection or vaccination.
The Japanese Encephalitis virus-specific IgM antibodies are detectable three to eight days after the onset of illness. The antibodies remain for 30-90 days. There also has been documentation of the antibodies staying for a longer time. If IgM antibodies are not evident in serum taken within ten days of the commencement of the illness, the test should be performed on a convalescent sample. In addition, patients with IgM antibodies to the JE virus must undergo Confirmatory neutralizing antibody testing. Nucleic acid amplification, histology with immunohistochemistry, and virus culture of postmortem tissues are other diagnostic methods that can be helpful in fatal instances.
However, because ELISAs need specialized equipment, their usage has been limited to a few academic or referral centers rather than the rural areas where Japanese Encephalitis is prevalent. For example, the IgM ELISA has recently been changed to a simple nitrocellulose membrane-based format that gives color change as an outcome/ result visible to the naked eye. This test, quick, easy to administer, and does not require any specialized equipment, should be helpful in rural hospitals for disease diagnosis. Sometimes the physician also recommends for CT or NRI scan of the brain. The reverse transcriptase-polymerase chain reaction has been used to detect Japanese encephalitis virus RNA in human CSF samples; however, its reliability as a regular diagnostic test has yet to be demonstrated.
Treatment and Management of Japanese Encephalitis
There is no particular drug or medication for curing Japanese Encephalitis viral infection. Interferon-α is the most promising prospective treatment at the moment. In response to the Japanese encephalitis virus infection, interferon-α is spontaneously produced naturally in the CSF. A placebo-controlled double-blinded clinical trial is currently being assessed to determine the therapeutic effect of recombinant interferon-α in patients with Japanese Encephalitis Virus.
Hospitalization with regular monitoring, proper diet, and supportive care are the primary methods to manage the severity of the disease and improve the patient’s recovery rate. Supportive care is required to control convulsions and raised intracranial pressure. Proper diet and regular monitoring are necessary to prevent malnutrition, bedsores, and contractures. However, antibiotics do not provide any therapeutic relief against the disease. In addition, there are drugs available to aid with brain swelling, and a person may require strong sedation and a breathing tube for a long time until the swelling subsides.
The only vaccine available in the United States to treat Japanese Encephalitis is the Inactivated Vero cell culture-derived Japanese encephalitis (JE) vaccine. The vaccine is approved for pediatrics of 2 months to adults of 18 years and older.
Methods to prevent the Japanese Encephalitis viral infection
- The key to avoiding vector-borne disease is to keep your surroundings neat and clean. Do not keep waste dumped near your house, and do not let water be stagnant near your home. Drainage pits should be covered and not clogged.
- Japanese Encephalitis mainly spreads among rural areas where people carry out pig farming and work in agricultural fields. Therefore, people should stay away from pigs, water birds and decrease the frequency of visiting rice paddy fields if there is no work.
- People living in vector-borne disease-endemic areas should have the habit of wearing full sleeve shirts and trousers when stepping outside of the home. Also, apply 0.5% permethrin to your clothes to keep mosquitoes at bay. However, one should not use permethrin directly on the skin.
- Insect-repellent creams help protect against mosquito bites. Insect repellents with an EPA registration are even safe for pregnant and breastfeeding women.
- Mosquito bed nets are mandatory to prevent mosquitoes from biting you at night when you are in a deep sleep. In addition, it prevents you from getting any mosquito-borne infectious disease.
- Parents should buy proper clothes for their babies and children covering their entire bodies.
- Always allow sunlight to enter your room and keep your room open for air to pass through. Cover the doors and windows with nets to prevent the entry of mosquitoes.
- Do not apply any essential oil to your skin without consultation from a physician. Read the label of the topical medicament carefully and follow the physician’s advice.
- Before visiting any place endemic with Japanese Encephalitis Viral Infection, travelers should bring mosquito nets, insect repellent lotions, full-sleeve shirts, long pants, and, if eligible, get a vaccination.
REFERENCES
- Japanese Encephalitis. Accessed at
https://www.oie.int/app/uploads/2021/03/japanese-encephalitis.pdf - Japanese Encephalitis. Accessed at
https://www.who.int/news-room/fact-sheets/detail/japanese-encephalitis - Japanese Encephalitis. Accessed at
https://www.cdc.gov/japaneseencephalitis/prevention/index.html - Solomon, T., Dung, N. M., Kneen, R., Gainsborough, M., Vaughn, D. W., & Khanh, V. T. (2000). Japanese Encephalitis. Journal of Neurology, Neurosurgery & Psychiatry, 68(4), 405-415.
- Japanese Encephalitis Diagnostic Testing. Accessed at
https://www.cdc.gov/japaneseencephalitis/healthcareproviders/healthcareproviders-diagnostic.html - Japanese Encephalitis Vaccine. Accessed at
https://www.cdc.gov/japaneseencephalitis/vaccine/index.html
