MyMedR

Serological evidence of DENV, JEV, and ZIKV among the indigenous people (Orang Asli) of Peninsular Malaysia

Khor CS, Mohd-Rahim NF, Hassan H, Tan KK, Zainal N, Teoh BT, et al.

J Med Virol, 2020 08;92(8):956-962.

Dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV) are mosquito-borne flavivirus of medical importance in tropical countries such as Malaysia. However, much remains unknown regarding their prevalence among the underserved indigenous people (Orang Asli) living in communities in the forest fringe areas of Peninsular Malaysia. Information on the prevalence of diseases is necessary to elevate the effectiveness of disease control and preventive measures. This study aimed to determine the seroprevalence of the three major flaviviruses among the Orang Asli and investigate the association between demographic factors and seropositivities. Sampling activities were conducted in the Orang Asli villages to obtain serum samples and demographic data from consenting volunteers. The presence of DENV, JEV, and ZIKV immunoglobulin G (IgG) antibodies in the sera were examined using commercial enzyme-linked immunosorbent assay kits. A focus reduction neutralization assay was performed to measure virus-specific neutralizing antibodies. A total of 872 serum samples were obtained from the Orang Asli volunteers. Serological assay results revealed that DENV IgG, JEV IgG, and ZIKV IgG seropositivities among the Orang Asli were at 4.9%, 48.4%, and 13.2%, respectively. Neutralizing antibodies (FRNT50 ≥ 1:40) against JEV and ZIKV were found in 86.7% and 100.0%, respectively, out of the samples tested. Positive serology to all three viruses corresponded significantly to the age of the volunteers with increasing seropositivity in older volunteers. Findings from the study suggest that Orang Asli are at significant risk of contracting JEV and ZIKV infections despite the lack of active transmission of the viruses in the country.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Fulltext Nineteen Years of Japanese Encephalitis Surveillance in Sabah, Malaysian Borneo

Montini Maluda MC, Jelip J, Ibrahim MY, Suleiman M, Jeffree MS, Binti Aziz AF, et al.

Am J Trop Med Hyg, 2020 08;103(2):864-868.

PMID: 32524958 DOI: 10.4269/ajtmh.19-0928

Japanese encephalitis (JE) is endemic in Malaysia. Although JE vaccination is practiced in the neighboring state of Sarawak for a long time, little is known about JE in Sabah state in Borneo. As a result, informed policy formulation for JE in Sabah has not been accomplished. In the present study, we have analyzed JE cases that have been reported to the Sabah State Health Department from 2000 to 2018. A total of 92 JE cases were reported during 19 years, and three-fourths of the cases were attributed to children. The estimated mean incidence for JE cases is 0.161/100,000 population. Japanese encephalitis was predominant in Sabah during June, July, and August, peaking in July. In most cases, pigs were absent within a 400-m radius of the place of residence. We could not establish any relationship between the mapping of JE cases and the number of piggeries in each district. We could not establish a relationship between average rainfall and JE cases, either. We propose the cases reported are possibly showing the tip of an iceberg and continuous surveillance is needed, as JE is a public health challenge in Sabah.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Fulltext Genetic diversity of Japanese encephalitis virus isolates obtained from the Indonesian archipelago between 1974 and 1987

Schuh AJ, Guzman H, Tesh RB, Barrett AD

Vector Borne Zoonotic Dis, 2013 Jul;13(7):479-88.

PMID: 23590316 DOI: 10.1089/vbz.2011.0870

Five genotypes (GI-V) of Japanese encephalitis virus (JEV) have been identified, all of which have distinct geographical distributions and epidemiologies. It is thought that JEV originated in the Indonesia-Malaysia region from an ancestral virus. From that ancestral virus GV diverged, followed by GIV, GIII, GII, and GI. Genotype IV appears to be confined to the Indonesia-Malaysia region, as GIV has been isolated in Indonesia from mosquitoes only, while GV has been isolated on three occasions only from a human in Malaysia and mosquitoes in China and South Korea. In contrast, GI-III viruses have been isolated throughout Asia and Australasia from a variety of hosts. Prior to this study only 13 JEV isolates collected from the Indonesian archipelago had been studied genetically. Therefore the sequences of the envelope (E) gene of 24 additional Indonesian JEV isolates, collected throughout the archipelago between 1974 and 1987, were determined and a series of molecular adaptation analyses were performed. Phylogenetic analysis indicated that over a 14-year time span three genotypes of JEV circulated throughout Indonesia, and a statistically significant association between the year of virus collection and genotype was revealed: isolates collected between 1974 and 1980 belonged to GII, isolates collected between 1980 and 1981 belonged to GIV, and isolates collected in 1987 belonged to GIII. Interestingly, three of the GII Indonesian isolates grouped with an isolate that was collected during the JE outbreak that occurred in Australia in 1995, two of the GIII Indonesian isolates were closely related to a Japanese isolate collected 40 years previously, and two Javanese GIV isolates possessed six amino acid substitutions within the E protein when compared to a previously sequenced GIV isolate collected in Flores. Several amino acids within the E protein of the Indonesian isolates were found to be under directional evolution and/or co-evolution. Conceivably, the tropical climate of the Indonesia/Malaysia region, together with its plethora of distinct fauna and flora, may have driven the emergence and evolution of JEV. This is consistent with the extensive genetic diversity seen among the JEV isolates observed in this study, and further substantiates the hypothesis that JEV originated in the Indonesia-Malaysia region.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Japanese encephalitis in Sarawak: studies on mosquito behaviour in a Land Dayak village

Bendell PJ

Trans R Soc Trop Med Hyg, 1970;64(4):497-502.

PMID: 4394985

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

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*

Fulltext A decade of Japanese encephalitis surveillance in Sarawak, Malaysia: 1997-2006

Wong SC, Ooi MH, Abdullah AR, Wong SY, Krishnan S, Tio PH, et al.

Trop Med Int Health, 2008 Jan;13(1):52-5.

PMID: 18291002 DOI: 10.1111/j.1365-3156.2007.01967.x

Japanese encephalitis virus (JEV) is an important encephalitis virus in Asia, but there are few data on Malaysia. A hospital-based surveillance system for Japanese encephalitis (JE) has been in operation in Sarawak, Malaysia, for the last 10 years. JEV is endemic in Sarawak, with cases occurring throughout the year and a seasonal peak in the last quarter (one-way anova, P < 0.0001). Ninety-two per cent of 133 cases were children aged 12 years or younger; the introduction of JE vaccination in July 2001 reduced the number of JE cases (84 in the four seasons prior to vs. 49 in the six seasons after, McNemar's test, P = 0.0001). After implementation of the programme, the mean age of infected children increased from 6.3 to 8.0 years (Student's t-test, P = 0.0037), suggesting the need for a catch-up programme.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

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*

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/epidemiology

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*

New virus fingered in Malaysian epidemic

Enserink M

Science, 1999 Apr 16;284(5413):407, 409-10.

PMID: 10232977 DOI: 10.1126/science.284.5413.407

Matched MeSH terms: Encephalitis, Japanese/epidemiology

Fulltext Emergence of Japanese encephalitis virus genotype V in the Republic of Korea

Takhampunya R, Kim HC, Tippayachai B, Kengluecha A, Klein TA, Lee WJ, et al.

Virol J, 2011;8:449.

PMID: 21943222 DOI: 10.1186/1743-422X-8-449

Japanese encephalitis virus (JEV) genotype V reemerged in Asia (China) in 2009 after a 57-year hiatus from the continent, thereby emphasizing a need to increase regional surveillance efforts. Genotypic characterization was performed on 19 JEV-positive mosquito pools (18 pools of Culex tritaeniorhynchus and 1 pool of Cx. bitaeniorhynchus) from a total of 64 positive pools collected from geographically different locations throughout the Republic of Korea (ROK) during 2008 and 2010.

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*

Japanese encephalitis in Sarawak: studies on adult mosquito populations

Hill MN

Trans R Soc Trop Med Hyg, 1970;64(4):489-96.

PMID: 4394984

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

Fulltext Japanese encephalitis virus is an important cause of encephalitis among children in Penang

Cardosa MJ, Hooi TP, Kaur P

Southeast Asian J. Trop. Med. Public Health, 1995 Jun;26(2):272-5.

PMID: 8629059

This study was carried out to determine if Japanese encephalitis virus is an important causative agent of viral encephalitis among pediatric admissions in Penang, Malaysia. 195 children with CNS symptoms and 482 children with non-specific febrile illness admitted into the Pediatric Ward of Penang Hospital during a 16 month period were entered into the study. The presence in serum of cerebrospinal fluid (csf) of Japanese encephalitis virus (JEV) specific IgM was determined by an IgM capture ELISA and cytomegalovirus (CMV) specific IgM was determined using a commercially available kit (Behringwerke AG). It was determined that 5 of 13 children with a discharge diagnosis of viral encephalitis had JEV specific IgM in csf, indicating that 38.5% of the viral encephalitis cases was due to JEV. One of the non-JEV cases was found to have mumps virus specific IgM in csf, while no etiology was determined for the other cases. It was also determined that 4 of the 195 (2.1%) cases with CNS symptoms had IgM to CMV, suggesting CMV may be an agent of encephalopathy in children in Penang. Other viruses found to be associated with CNS symptoms in children admitted into our study were measles and herpes simplex virus. A viral etiology was confirmed for 13 or the 195 cases (6.7%). We also screened 482 non-specific febrile cases for IgM to JEV and to dengue viruses and found that 2 (0.4%) had IgM specific for JEV and 9 (1.9%) had IgM specific for dengue virus.

Matched MeSH terms: Encephalitis, Japanese/epidemiology

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*

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*

Fulltext Southernmost Asia is the source of Japanese encephalitis virus (genotype 1) diversity from which the viruses disperse and evolve throughout Asia

Gao X, Liu H, Wang H, Fu S, Guo Z, Liang G

PLoS Negl Trop Dis, 2013;7(9):e2459.

PMID: 24069502 DOI: 10.1371/journal.pntd.0002459

Although a previous study predicted that Japanese encephalitis virus (JEV) originated in the Malaysia/Indonesia region, the virus is known to circulate mainly on the Asian continent. However, there are no reported systematic studies that adequately define how JEV then dispersed throughout Asia.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

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/epidemiology*

Japanese encephalitis in Sarawak: virus isolation and serology in a Land Dyak village

Simpson DI, Bowen ET, Platt GS, Way H, Smith CE, Peto S, et al.

Trans R Soc Trop Med Hyg, 1970;64(4):503-10.

PMID: 4394986

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

The appearance of a second genotype of Japanese encephalitis virus in the Australasian region

Pyke AT, Williams DT, Nisbet DJ, van den Hurk AF, Taylor CT, Johansen CA, et al.

Am J Trop Med Hyg, 2001 Dec;65(6):747-53.

PMID: 11791969

In mid-January 2000, the reappearance of Japanese encephalitis (JE) virus activity in the Australasian region was first demonstrated by the isolation of JE virus from 3 sentinel pigs on Badu Island in the Torres Strait. Further evidence of JE virus activity was revealed through the isolation of JE virus from Culex gelidus mosquitoes collected on Badu Island and the detection of specific JE virus neutralizing antibodies in 3 pigs from Saint Pauls community on Moa Island. Nucleotide sequencing and phylogenetic analyses of the premembrane and envelope genes were performed which showed that both the pig and mosquito JE virus isolates (TS00 and TS4152, respectively) clustered in genotype I, along with northern Thai, Cambodian, and Korean isolates. All previous Australasian JE virus isolates belong to genotype II, along with Malaysian and Indonesian isolates. Therefore, for the first time, the appearance and transmission of a second genotype of JE virus in the Australasian region has been demonstrated.

Matched MeSH terms: Encephalitis, Japanese/epidemiology*

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