जे पत्र

इन्फ्लुएंजा क्या है?

जापानी मस्तिष्ककोप (JE) है a rare but potentially serious disease caused by infection with Japanese encephalitis virus (JEV). जेईवी is a flavivirus (other flaviviruses cause diseases including पीला बुखार, dengue and Murray Valley encephalitis). एसpread to humans through mosquito bites, जेईवी is a leading cause of vaccine-preventable encephalitis (brain inflammation) in Asia and the Western Pacific.

किसकी तलाश है?

Most people infected with JEV do not develop symptoms or develop mild symptoms only. However, approximately 1 in 250 people infected will experience severe clinical illness. If symptoms develop, they will occur 5 to 15 days after exposure और can include fever, diarrhoea and rigors (episodes of shivering and feeling cold). Feएtures of severe illness with encephalitis include एचeadache, confusion, vomiting, paralysis, seizures, neck stiffness, disorientation and coma. JE has ए mortality rate of 20 to 30%, with permanent neurological disability occurring in 30 to 50% of survivors.

यह कैसे संचारित होता है?

JE is a zoonotic disease and can spread to humans when a mosquito bites an infected animal (mostly water birds or pigs) and then bites a human. It cannot be transmitted from person to person, or through eating pork or pig products. Horses can be infected with JEV; however, they cannot transmit the disease further.

When JE occurs during pregnancy, infection can be transmitted to the unborn baby.

In most temperate areas of Asia and Australia, JEV is transmitted mainly during the warmer months. In the tropics and subtropics, transmission can occur year-round but often intensifies during the rainy season when mosquito numbers are greater.

एपिडेमियोलॉजी (महामारी विज्ञान)

There are an estimated 100,000 clinical cases of JE globally each year, resulting in approximately 25,000 deaths. JE is most common across Asia and the Western Pacific. In the 1990s, cases were reported in the Torres Strait Islands and in Cape York (mainland Australia).  In 2022 and 2023, cases occurred in the Murray and Riverina regions of south-eastern Australian states.

Where JEV is present, people with increased exposure to mosquitoes are at higher risk of infection, particularly those spending time outdoors or working with pigs. Children under 5 years of age and older people who are infected with JEV are at higher risk of more severe illness, including encephalitis.

रोकथामं

वास्तविक बाधाएं

Preventing mosquito bites with physical barriers is the most effective way to avoid infection with JEV. Exposure to mosquito bites can be prevented by: 

• बाहर जाने पर लंबे, ढीले-ढाले कपड़े पहनना
• पिकारिडिन या डीईईटी युक्त मच्छर निरोधकों का उपयोग करना
• यदि बहुत सारे मच्छर हों तो बाहरी गतिविधियों को सीमित कर दें
• फ्लाई स्प्रे, मच्छर कॉइल और प्लग-इन प्रतिरोधी उपकरणों का उपयोग करना
• यदि आपकी खिड़कियों पर फ्लाईवायर स्क्रीन नहीं है या आप किसी उपचारित तंबू में/बाहर खुले में सो रहे हैं, तो कीटनाशकों से उपचारित मच्छरदानी के नीचे सोएं।

टीके

Vaccines are also available to prevent the development of बीमारी। There are currently two JE vaccines available in Australia: इमोजेव और जेस्पेक्ट.  Vaccination is recommended for:

• all research laboratory workers at risk of exposure to JEV
• travellers spending 1 month or more in areas outside of Australia with endemic JEV transmission
• people who live or work in the outer islands in the Torres Strait (for a cumulative total of 30 days or more) during the wet season (December to May).

Other individuals with specific risk factors are prioritised and funded to receive vaccines through state-led programs:

• Victoria
• News South Wales
• Queensland

Table 1: Vaccine brands and dose recommendations

shaded boxes indicate live-attenuated vaccines, which are contraindicated for प्रेग्नेंट औरत and people who are immunocompromised.
* Intradermal (ID) administration of Imojev (single dose of 0.1 mL) may be used as a dose-sparing strategy for heatlhy adults (non-pregnant, non-breastfeeding, no immunocompromise) aged ≥ 18 years in circumstances where public health benefits outweigh potential risk as determined by State/Territory health authorities.
^JEspect is an inactivated vaccine and is therefore suitable for administration in pregnant women or immunocompromised individuals.
# The interval between doses of JEspect can be shortened to 7 days for those aged ≥ 18 years, if the individual is at imminent risk of JEV exposure.
Ω Where possible the same brand of vaccine should be used for the booster dose as the primary course. Based on first prinicples, use of the alternate brand should provide a satisfactory immune response however there are no studies confirming this.

दुष्प्रभाव

Expected side effects following either vaccine are usually mild and short lived. They can include injection site pain, redness and swelling, as well fever, headaches and muscle aches.

संसाधन

• विक्टोरियन स्वास्थ्य विभाग: विक्टोरिया में जापानी एन्सेफलाइटिस
• ऑस्ट्रेलियाई टीकाकरण पुस्तिका: जापानी एन्सेफलाइटिस
• ATAGI statement on the intradermal use of Imojev Japanese encephalitis vaccine
• ऑस्ट्रेलियाई सरकार के स्वास्थ्य और वृद्ध देखभाल विभाग: जापानी एन्सेफलाइटिस वायरस की स्थिति को राष्ट्रीय महत्व की संचारी रोग घटना घोषित किया गया
• जापानी एन्सेफलाइटिस वायरस के खिलाफ टीकाकरण के संबंध में सीडीएनए सलाह