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Japanese type B encephalitis in Malaya

HALE JH, LIM KA, CHEE PH

Ann Trop Med Parasitol, 1952 Nov;46(3):220-6.

PMID: 13008352

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Short report: a major genotype of Japanese encephalitis virus currently circulating in Japan

Ma SP, Yoshida Y, Makino Y, Tadano M, Ono T, Ogawa M

Am J Trop Med Hyg, 2003 Aug;69(2):151-4.

PMID: 13677370

A 240-nucleotide sequence of the capsid/premembrane gene region of 23 Japanese encephalitis virus (JEV) strains isolated in Tokyo and Oita, Japan was determined and phylogenetic analyses were performed. All the strains clustered into two distinct genotypes (III and I). All strains isolated before 1991 belonged to genotype III, while those isolated after 1994 belonged to genotype I. In addition, the strains of the genotype I isolated in Japan showed a close genetic relationship with those from Korea and Malaysia.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*; Encephalitis, Japanese/virology*

Outbreak of Japanese encephalitis hits Malaysia

Easton A

BMJ, 1999 Apr 03;318(7188):893.

PMID: 10102839 DOI: 10.1136/bmj.318.7188.893a

Matched MeSH terms: Encephalitis, Japanese/epidemiology*; Encephalitis, Japanese/prevention & control

Studies on arbovirus epidemiology associated with established and developing rice culture. Introduction

Smith CE

Trans R Soc Trop Med Hyg, 1970;64(4):481-2.

PMID: 4320902

Matched MeSH terms: Encephalitis, Japanese/epidemiology*; Encephalitis, Japanese/veterinary

Methods of sampling population of the Japanese encephalitis vector mosquitoes. A preliminary report

Ree HI, Chen YK, Chow CY

Med J Malaya, 1969 Jun;23(4):293-5.

PMID: 4310350

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Further observations on geographic variation in the antigenic character of West Nile and Japanese B viruses

Hammam HM, Price WH

Am J Epidemiol, 1966 Jan;83(1):113-22.

PMID: 4286367

Matched MeSH terms: Encephalitis, Japanese*

Serological evidence of the incidence of Japanese B encephalitis virus infection in Malaysia

HALE JH, LEE LH

Ann Trop Med Parasitol, 1955 Oct;49(3):293-8.

PMID: 13259442

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Japanese encephalitis in Malaya. II. Distribution of neutralizing antibodies in man and animals

POND WL, RUSS SB, LANCASTER WE, AUDY JR, SMADEL JE

Am J Hyg, 1954 Jan;59(1):17-25.

PMID: 13124320

Matched MeSH terms: Encephalitis, Japanese/immunology*

Japanese encephalitis in Malaya. I. Isolation of virus and serologic evidence of human and equine infections

PATERSON PY, LEY HL, WISSEMAN CL, POND WL, SMADEL JE, DIERCKS FH, et al.

Am J Hyg, 1952 Nov;56(3):320-33.

PMID: 12996500

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

A hospital-based surveillance for Japanese encephalitis in Bali, Indonesia

Kari K, Liu W, Gautama K, Mammen MP, Clemens JD, Nisalak A, et al.

BMC Med, 2006;4:8.

PMID: 16603053

Japanese encephalitis (JE) is presumed to be endemic throughout Asia, yet only a few cases have been reported in tropical Asian countries such as Indonesia, Malaysia and the Philippines. To estimate the true disease burden due to JE in this region, we conducted a prospective, hospital-based surveillance with a catchment population of 599,120 children less than 12 years of age in Bali, Indonesia, from July 2001 through December 2003.

Matched MeSH terms: Encephalitis, Japanese/diagnosis; Encephalitis, Japanese/epidemiology*; Encephalitis, Japanese/prevention & control

Fulltext Investigation of a suspected outbreak of Japanese encephalitis in Pulau Langkawi

Fang R, Hsu DR, Lim TW

Malays J Pathol, 1980 Aug;3:23-30.

PMID: 6312203

Matched MeSH terms: Encephalitis, Japanese/diagnosis; Encephalitis, Japanese/epidemiology*; Encephalitis, Japanese/transmission

Fulltext Japanese encephalitis in Malaysia: An overview and timeline

Kumar K, Arshad SS, Selvarajah GT, Abu J, Toung OP, Abba Y, et al.

Acta Trop, 2018 Sep;185:219-229.

PMID: 29856986 DOI: 10.1016/j.actatropica.2018.05.017

Japanese encephalitis (JE) is a vector-borne zoonotic disease caused by the Japanese encephalitis virus (JEV). It causes encephalitis in human and horses, and may lead to reproductive failure in sows. The first human encephalitis case in Malaya (now Malaysia) was reported during World War II in a British prison in 1942. Later, encephalitis was observed among race horses in Singapore. In 1951, the first JEV was isolated from the brain of an encephalitis patient. The true storyline of JE exposure among humans and animals has not been documented in Malaysia. In some places such as Sarawak, JEV has been isolated from mosquitoes before an outbreak in 1992. JE is an epidemic in Malaysia except Sarawak. There are four major outbreaks reported in Pulau Langkawi (1974), Penang (1988), Perak and Negeri Sembilan (1998-1999), and Sarawak (1992). JE is considered endemic only in Sarawak. Initially, both adults and children were victims of JE in Malaysia, however, according to the current reports; JE infection is only lethal to children in Malaysia. This paper describes a timeline of JE cases (background of each case) from first detection to current status, vaccination programs against JE, diagnostic methods used in hospitals and factors which may contribute to the transmission of JE among humans and animals in Malaysia.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*; Encephalitis, Japanese/prevention & control; Encephalitis, Japanese/transmission

Fulltext The current burden of Japanese encephalitis and the estimated impacts of vaccination: Combining estimates of the spatial distribution and transmission intensity of a zoonotic pathogen

Moore SM

PLoS Negl Trop Dis, 2021 10;15(10):e0009385.

PMID: 34644296 DOI: 10.1371/journal.pntd.0009385

Japanese encephalitis virus (JEV) is a major cause of neurological disability in Asia and causes thousands of severe encephalitis cases and deaths each year. Although Japanese encephalitis (JE) is a WHO reportable disease, cases and deaths are significantly underreported and the true burden of the disease is not well understood in most endemic countries. Here, we first conducted a spatial analysis of the risk factors associated with JE to identify the areas suitable for sustained JEV transmission and the size of the population living in at-risk areas. We then estimated the force of infection (FOI) for JE-endemic countries from age-specific incidence data. Estimates of the susceptible population size and the current FOI were then used to estimate the JE burden from 2010 to 2019, as well as the impact of vaccination. Overall, 1,543.1 million (range: 1,292.6-2,019.9 million) people were estimated to live in areas suitable for endemic JEV transmission, which represents only 37.7% (range: 31.6-53.5%) of the over four billion people living in countries with endemic JEV transmission. Based on the baseline number of people at risk of infection, there were an estimated 56,847 (95% CI: 18,003-184,525) JE cases and 20,642 (95% CI: 2,252-77,204) deaths in 2019. Estimated incidence declined from 81,258 (95% CI: 25,437-273,640) cases and 29,520 (95% CI: 3,334-112,498) deaths in 2010, largely due to increases in vaccination coverage which have prevented an estimated 314,793 (95% CI: 94,566-1,049,645) cases and 114,946 (95% CI: 11,421-431,224) deaths over the past decade. India had the largest estimated JE burden in 2019, followed by Bangladesh and China. From 2010-2019, we estimate that vaccination had the largest absolute impact in China, with 204,734 (95% CI: 74,419-664,871) cases and 74,893 (95% CI: 8,989-286,239) deaths prevented, while Taiwan (91.2%) and Malaysia (80.1%) had the largest percent reductions in JE burden due to vaccination. Our estimates of the size of at-risk populations and current JE incidence highlight countries where increasing vaccination coverage could have the largest impact on reducing their JE burden.

Matched MeSH terms: Encephalitis, Japanese/epidemiology; Encephalitis, Japanese/prevention & control*; Encephalitis, Japanese/transmission; Encephalitis, Japanese/virology

Fulltext Japanese Encephalitis in Assam, India: Need to Increase Healthcare Workers' Understanding to Improve Health Care

Ahmad A, Khan MU, Gogoi LJ, Kalita M, Sikdar AP, Pandey S, et al.

PLoS One, 2015;10(8):e0135767.

PMID: 26296212 DOI: 10.1371/journal.pone.0135767

INTRODUCTION: Japanese encephalitis (JE) is a major cause of high morbidity and mortality in several states across India. However, in 2014, a sharp rise was observed in the number of cases of JE in north-eastern Assam state, and 51% of the total cases of JE in India were reported from the Assam in the same year. In this regard, a study was conducted to evaluate the knowledge and attitudes of healthcare workers in Darrang, a district of Assam highly affected by JE.

METHODS: A cross sectional study was conducted for 2 months among HCWs in the major district hospital of Darrang, Assam. A pre-tested, self-administered questionnaire was used to collect data from the participants. Convenience sampling approach was used to collect data from different departments of the hospitals. Descriptive and logistic regression analyses were used to express the results.

RESULTS: The knowledge of HCWs regarding JE was poor with a mean knowledge score of 11.02±2.39 (out of 17), while their attitudes were positive with a mean attitudes score of 43.16± 2.47 (ranging from 13 to 52). Overall, 40.4% and 74.3% of participants demonstrated good knowledge and positive attitudes respectively. Cut-off score for good knowledge and positive attitudes toward JE was set as ≥12 and >40 respectively. Older participants (40-49 years) and experienced workers (>10 years) were significantly associated with good knowledge as compared to their referent group (p<0.05), while knowledge of nurses and other orderlies were significantly lower than physicians (p<0.01). Similar factors were associated with the positive attitudes of the participants with the exception of experience. Television was the major source of information regarding JE reported by HCWs (79%).

CONCLUSION: Although the knowledge was not optimized, HCWs exhibited positive attitudes towards JE. Future research is required to design, implement and evaluate interventions to improve the knowledge of JE among HCWs.

Matched MeSH terms: Encephalitis, Japanese/diagnosis; Encephalitis, Japanese/epidemiology; Encephalitis, Japanese/psychology*; Encephalitis, Japanese/therapy

A review of Japanese-B virus encephalitis in Malaysia

Sinniah M

Southeast Asian J. Trop. Med. Public Health, 1989 Dec;20(4):581-5.

PMID: 2561714

JE is neither classified as an entity in the Malaysian Medical records system nor is it a notifiable disease but is grouped under the broad umbrella of viral encephalitis. There is no centralised program by the Ministry of Health specially for JE surveillance and control. JE is endemic, occurs sporadically throughout the country all year round. Asymptomatic inapparent infections have been found to be more frequent than acute clinical encephalitis cases, judging from results of previous serosurveys (Pond et al., 1954). JE vaccination has never been tried in Malaysia. In a relative sense, JEV infection unlike dengue virus infection, does not appear to be much of a problem in Malaysia. Perhaps, the laboratory confirmed cases represent only a small proportion of the total hospitalised cases that actually occurred. The reasons may be that these cases could not be confirmed by laboratory tests due to improper timing or failure to obtain the second serum specimen, or failure to perform lumbar puncture on patient's refusal. Attempts to improve the case detection rate of JE in Malaysia should be made namely, by increasing clinical index of suspicion, instituting better specimen collection procedures and by adopting rapid diagnostic tests.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Japanese encephalitis in Sarawak: studies on juvenile mosquito populations

Heathcote OH

Trans R Soc Trop Med Hyg, 1970;64(4):483-8.

PMID: 4394983

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

A serological survey of antibodies to Japanese B encephalitis virus among horses in Malaya

HALE JH, WITHERINGTON DH

Ann Trop Med Parasitol, 1954 Mar;48(1):15-20.

PMID: 13149114

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

A serological investigation of six encephalitis viruses isolated in Malaya