Urban Japanese Encephalitis: Time for a Reality Check

  • Sajal Bhattacharya Department of Zoology, Asutosh College (University of Calcutta), Kolkata, West Bengal, India.
  • Shakya Sinha Department of Zoology, Asutosh College (University of Calcutta), Kolkata, West Bengal, India.
  • Chandrima Bose Department of Zoology, Asutosh College (University of Calcutta), Kolkata, West Bengal, India.
  • Pallab Chatterjee Department of Zoology, Asutosh College (University of Calcutta), Kolkata, West Bengal, India.
  • Rina Tilak Department of Community Medicine, Armed Forces Medical College, Pune, Maharashtra, India. https://orcid.org/0000-0003-3781-0210
Keywords: Japanese Encephalitis, Virus, Vector, Reservoir, Urban Areas


Expansion of JEV from its historical rural origin in the Oriental Realm has been evident. Apprehensions were raised by several investigators that the occurrence of Japanese Encephalitis (JE) in the urban areas is a possibility. Creating wetlands, rice farms, and piggeries close to the rural-urban periphery to support the increasing urban population facilitates the migration of mosquitoes, ardeid birds, and pigs in these areas. The presence of vectors (Culex vishnui complex), reservoirs (the ardeid birds), and the amplifying hosts (pigs) together in these urban and peri-urban areas creates highly conducive situations for the JE transmission thus, creating an urban ecotype for JE. Apart from the primary vectors, JEV has been isolated from several species of mosquitoes belonging to different genera. JE antibodies have also been detected in several birds and mammals other than the known reservoirs and amplifying hosts. Such mosquitoes, birds, and mammals might be acting as complementary or maintenance vectors and reservoirs, respectively, which likely can keep the virus circulating perennially in nature. The reported occurrence of JE in urban areas from different geographical locations is decidedly indicative of the reality of the urban JE. It is thus pertinent that an inclusive approach encompassing sustained epidemiological surveillance and monitoring be adopted to formulate season-wise and area-wise strategies to contain JE both in rural and urban areas.

How to cite this article:
Bhattacharya S, Sinha S, Bose C, Chatterjee P, Tilak R. Urban Japanese Encephalitis: Time for a Reality Check. J Commun Dis 2021; 53(1): 72-77.

DOI: https://doi.org/10.24321/0019.5138.202112


Bhattacharya S, Basu P. Japanese Encephalitis Virus (JEV) infection in different vertebrates and its epidemiological significance: A review. Int J of Fauna and Biol Studies 2014; 1(6): 32-37.

WHO. Japanese Encephalitis Reported Cases, World Health Organization. 2019 Available from: https://


Weaver SC, Barrett AD. Transmission cycles, host range, evolution and emergence of arboviral disease. Nat Rev

Microbiol 2004; 2(10): 789-801.

Kumari R, Kumar K, Rawat A et al. First indigenous transmission of Japanese Encephalitis in urban areas

of National Capital Territory of Delhi, India. Trop MedInt Health 2013; 18(6): 743-9.

Rosen L. The natural history of Japanese encephalitis virus. Annu Rev Microbiol 1986; 40: 395-414.

Lindahl J. Urbanization and vector-borne disease emergence - a possibility for Japanese Encephalitis

virus? British J of Virology 2014; 1(1): 10-20.

Vajpayee A, Mukherjee MK, Chakraborty AK et al. Investigation of an outbreak of Japanese encephalitis

in Rourkela City (Orissa) during 1989. J Commun Dis 1991; 23(1): 18-21.

Dash AP, Chhotray GP, Mahapatra N et al. Retrospective analysis of epidemiological investigation of Japanese

encephalitis outbreak occurred in Rourkela, Orissa, India. Southeast Asian J Trop Med Public Health 2001;

(1): 137-139.

Taraphdar D, Sarkar A, Mukhopadhyay BB et al. Increasing trend of Japanese encephalitis cases in

West Bengal, India - a threat to paediatric population. Asia Pacific J of Tropical Med 2012; 2(5): 358-361.

Chakraborty D, Banerjee S, Maji D et al. A descriptive study of Japanese encephalitis in West Bengal, India,

based on surveillance data: changing pattern observed in recent years. Sch J App Med Sci 2015; 3(1E): 320-328.

Bhattacharya S, Santra SC. Mosquito-borne diseases and vector diversity in Kolkata with special to Malaria.

In.: Perspectives in Environmental Health: vector and water borne diseases (Eds.: Mukhopadhyay A, Dey AK.)

Published by Originals, Delhi, India. 2005, pp.53-70.

Chakraborty DC, Majumdar S. Urban Heronries of Kolkata Metropolitan: an insight to nest stratification,

resource based guilds and conservation priorities. Asian J of Conservation Biol 2018; 7(2): 106-12.

Khan RH, Islam M, Akter T et al. Diversity of mosquitoes and their seasonal fluctuation in two wards of Dhaka

city. Dhaka Univ J of Biol Sci 2014; 23(1): 17‐26.

Hossain MJ, Gurley ES, Montgomery S et al. Hospitalbased surveillance for Japanese encephalitis at four

sites in Bangladesh, 2003-2005. Am J Trop Med Hyg 2010; 82(2): 344-349.

Fang Y, Zhang Y, Zhou ZB et al. New strains of Japanese encephalitis virus circulating in Shanghai, China after a ten-year hiatus in local mosquito surveillance. Parasites and Vectors 2019; 12(22): 1-14.

Lindahl J, Chirico J, Boqvist S et al. Occurrence of Japanese encephalitis virus mosquito vectors in relation

to urban pig holdings. Am J Trop Med Hyg 2012; 87(6): 1076-1082.

Di Francesco J, Choeung R, Peng B et al. Comparison of the dynamics of Japanese encephalitis virus circulation in sentinel pigs between a rural and a peri-urban setting in Cambodia. PLoS Negl Trop Dis 2018; 12(8): e0006644.

Chu H, Wu Z, Chen H et al. Japanese encephalitis virus infection rate and detection of genotype i from culex

tritaeniorhynchus collected from Jiangsu, China. Vector Borne Zoonotic Dis 2017; 17(7): 503-509.

Pearce JC, Learoyd TP, Langendorf BJ et al. Japanese encephalitis: the vectors, ecology and potential for

expansion. J Travel Med 2018; 25(suppl_1): S16-26.

Reuben R, Tewari SC, Hiriyan J et al. Illustrated keys to species of Culex (Culex) associated with Japanese

encephalitis in Southeast Asia (Diptera: Culicidae). Mosquito Systematics 1994; 26: 75-96.

Le Flohic G, Porphyre V, Barbazan P et al. Review of climate, landscape, and viral genetics as drivers of the

Japanese encephalitis virus ecology. PLoS Negl Trop Dis 2013; 7(9): e2208.

Dhanda V, Banerjee K, Deshmukh PK et al. Experimental viraemia and transmission of Japanese encephalitis

virus by mosquitoes in domestic ducks. Indian J Med Res 1977; 66(6): 881-888.

Thenmozhi V, Balaji T, Venkatasubramani K et al. Role of Anopheles subpictus Grassi in Japanese encephalitis

virus transmission in Tirunelveli, South India. Indian J Med Res 2016; 144(3): 477-481.

Mourya DT, Ilkal MA, Mishra AC et al. Isolation of Japanese encephalitis virus from mosquitoes collected

in Karnataka state, India from 1985 to 1987. Trans R Soc Trop Med Hyg 1989; 83(4): 550-552.

de Wispelaere M, Desprès P, Choumet V. European Aedes albopictus and Culex pipiens Are Competent

Vectors for Japanese Encephalitis Virus. PLoS Negl Trop Dis 2017; 11(1): e0005294.

Huber K, Jansen S, Leggewie M et al. Aedes japonicus japonicus (Diptera: Culicidae) from Germany have

vector competence for Japan encephalitis virus but are refractory to infection with West Nile virus. Parasitol

Res 2014; 113(9): 3195-3199.

Mackenzie-Impoinvil L, Impoinvil DE, Galbraith SE et al. Evaluation of a temperate climate mosquito,

Ochlerotatus detritus (=Aedes detritus), as a potential vector of Japanese encephalitis virus. Med Vet Entomol

; 29(1): 1-9.

Tyagi BK, Thenmozhi V, Karthigai SS. Transmission dynamics of Japanese encephalitis with emphasis on

gaps in understanding and priority areas for research on Japanese encephalitis and other acute encephalitis

syndrome in India. J Commun Dis 2014; 46: 24-34.

Filgueira L, Lannes N. Review of emerging Japanese encephalitis virus: new aspects and concepts about entry

into the brain and inter-cellular spreading. Pathogens 2019; 8(3): 111.

Mackenzie JS, Williams DT, Smith DW. Japanese encephalitis virus: the geographic distribution,

incidence and spread of a virus with a propensity to emerge in new areas. Perspectives in Med Virol 2006;

: 201-268.31. Ricklin ME, García-Nicolás O, Brechbühl D et al. Vector-free transmission and persistence of Japanese encephalitis virus in pigs. Nat Commun 2016; 7: 10832.

Wang JL, Pan XL, Zhang HL et al. Japanese encephalitis viruses from bats in Yunnan, China. Emerg Infect Dis

; 15(6): 939-942.

Lee H, Min B, Lim Y. Isolation and serologic studies of Japanese encephalitis virus from snakes in Korea. J

Korean Am Med Assoc 1972; 15: 69-74.

Shortridge KF, Oya A, Kobayashi M et al. Arbovirus infections in reptiles: studies on the presence of

Japanese encephalitis virus antibody in the plasma of the turtle, Trionyx sinensis. Southeast Asian J Trop

Med Public Health 1975; 6(2): 161-169.

Sehgal RN. Deforestation and avian infectious diseases. J Exp Biol 2010; 213(6): 955-960.

Erlanger TE, Weiss S, Keiser J et al. Past, present, and future of Japanese encephalitis. Emerg Infect Dis 2009;

(1): 1-7.

Solomon T. Control of Japanese encephalitis--within our grasp? N Engl J Med 2006; 355(9): 869-871.

Hanna JN, Ritchie SA, Phillips DA et al. An outbreak of Japanese encephalitis in the Torres Strait, Australia,

Med J Aust 1996; 165(5): 256-260.

Hsu SM, Yen AM, Chen TH. The impact of climate on Japanese encephalitis. Epidemiol Infect 2008; 136(7):


Sakamoto R, Tanimoto T, Takahashi K et al. Flourishing Japanese encephalitis, associated with global warming

and urbanisation in Asia, demands widespread integrated vaccination programmes. Ann Glob Health

; 85(1): 111.

Caminade C, McIntyre KM, Jones AE. Impact of recent and future climate change on vector-borne

diseases. Ann N Y Acad Sci 2019; 1436(1): 157-173.

Traut, AH, Hostetler ME. Urban lakes and water birds: effects of development on avian behavior. Water birds:

The Int J of Waterbird Biol 2003; 26(3): 290-302.

Hati AK, Bhattacharya S. Biosystematics of Culex Vishnui and Culex pseudovishnui based on eco-behavioral

pattern. Proc Ind Acad SCI (Anim. Sci.) 1987; 96: 629-636.

Bhattacharya S, Chakraborty SK, Chakraborty S et al. Density of Culex vishnui and appearance of JE antibody

in Sentinel chicks and wild birds in relation to Japanese encephalitis cases. Trop Geogr Med 1986; 38: 46-50.

Bhattacharya S. Mosquito Borne diseases in India with special reference to Malaria Vectors and their Control.

J of the Asiatic Society 2009; L1(2): 15-34.

Bhattacharya S, Chakraborty S, Mitra AK, et al. Blood meal analysis of certain species of mosquitoes of rural

West Bengal. Bull Cal Sch Trop Med 1982; 30: 43-45.

Bhattacharya S, Basu P. The Southern House Mosquito, Culex quinquefasciatus: profile of a smart vector. J Ent and Zoo Studies 2016; 4(2): 73-81.

Nitatpattana N, Apiwathnasorn C, Barbazan P et al. First isolation of Japanese encephalitis from Culex

quinquefasciatus in Thailand. Southeast Asian J Trop Med Public Health 2005; 36(4): 875-878.

Partridge J, Ghimire P, Sedai T, et al. Endemic Japanese encephalitis in the Kathmandu valley, Nepal. Am J Trop

Med Hyg 2007; 77(6): 1146-9.

Bhattacharya S, Hati AK. Transmission Dynamics of Japanese encephalitis in an endemic area of India.

Acta Parasitologica Portuguesa 1998; 5(1): 6.