Japanese encephalitis virus: epidemiology and risk-based surveillance approaches for New Zealand

The introduction and subsequent rapid spread of Japanese encephalitis virus genotype IV across all Australian mainland states and the Northern Territory since late 2021 has increased the risk of an incursion of this mosquito-transmitted zoonotic virus disease into New Zealand, with serious implications for both animal and human health. The potential modes of entry are through introduction of infected mosquitoes as hitchhikers on ships or aircraft, windborne transfer of mosquitoes, or arrival of infected reservoir bird species. A competent vector mosquito, Culex quinquefasciatus, is endemic in New Zealand and other mosquito species may also become involved. If infection becomes established in New Zealand, the scale of transmission may be considerably less than has occurred in Australia because climatic and epidemiological factors are not so favourable. Early evidence of an incursion could come from detection of clinical disease in horses or pigs, or from human cases. Targeted surveillance to confirm or refute indications of an incursion could be undertaken by antibody detection in a number of species. Dogs have been shown to be a particularly valuable sentinel species due to their cohabitation with people and high seroconversion rate. Other novel methods of surveillance could include reverse transcriptase PCR (RT-PCR) on oronasal secretions of pigs. Should evidence of the disease be detected, prompt action would be required to vaccinate at-risk human populations and clarify the epidemiological situation with respect to mammalian hosts and mosquito vector species, including whether a new mosquito species had arrived in the country.Abbreviations: AHL: Animal Health Laboratory; JE: Japanese encephalitis disease; JEV: Japanese encephalitis virus; RT-PCR: Reverse transcriptase PCR.

A review on Japanese Encephalitis virus emergence, pathogenesis and detection: From conventional diagnostics to emerging rapid detection techniques

The virus known as Japanese Encephalitis (JEV) is among the common viral persisting Encephalitis caused by Flavivirus around the Globe, especially in Southeast Asian nations. JEV may be a leading reason for neurological illness in humans, with an estimated 70,000 human cases and 10,000 fatalities per annum. The conventional methods like PRNT (Plaque Reduction Neutralization Test), ELISA (Enzyme-linked immunosorbent assay) RT-PCR (reverse transcription-polymerase chain reaction), and virus isolation are few commercial tests being availed these days, but they have a variety of drawbacks, including being extremely expensive, time-consuming, and requiring expertise. Therefore, researches are being made in the development of improved inexpensive, shorter, sensitive, and time-saving strategies to diagnose the Japanese Encephalitis Virus. A number of these researches encompass the employment of immunosensors, electrochemical sensors and along with the applications of nanotechnology to create highly sensitive detecting device. This review article is based on contemporary breakthroughs in diagnosing Japanese Encephalitis Virus, which are crucial in severing the connection between the propagation of zoonotic disease into the current race, where humans function as dead-end hosts.

Japanese Encephalitis: A Brief Review on Indian Perspectives

Introduction:

Japanese encephalitis (JE) is recently declared as a notifiable disease in India due to its expanding geographical distribution. The disease notification facilitates effective implementation of preventive measures and case management.

Expalantion:

JE is a vector-borne disease that can be prevented by vaccine administration. It is caused by Japanese encephalitis virus (JEV), belonging to family Flaviviridae. Amongst the known etiological viral encephalitis agents, it is one of the leading viral agents of acute encephalitis syndrome in many Asian countries where it is identified to cause substantial morbidity and mortality as well as disability. Globally, it is responsible for approximately 68,000 clinical cases every year.

Conclusion:

In the absence of antivirals, patients are given supportive treatment to relieve and stabilize. Amongst available control strategies; vector control is resource intensive while animal and human vaccination are the most effective tool against the disease. This review highlights recent progress focusing challenges with diagnosis and prophylactic interventions.