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  1. Fulltext Entomological Surveillance Associated with Human Zika Cases in Miri Sarawak, Malaysia
    Ali R, Azmi RA, Wasi Ahmad N, Abd Hadi A, Muhamed KA, Rasli R, et al.
    Am J Trop Med Hyg, 2020 May;102(5):964-970.
    PMID: 32228777 DOI: 10.4269/ajtmh.19-0339
    Two confirmed human cases of Zika virus (ZIKV) were reported in the district of Miri, Sarawak, in 2016. Following that, a mosquito-based ZIKV surveillance study was conducted within 200-m radius from the case houses. Mosquito surveillance was conducted using five different methods, that is, biogents sentinel mosquito (BG) sentinel trap, modified sticky ovitrap, resting catch, larval surveillance, and conventional ovitrap. A total of 527 and 390 mosquito samples were obtained from the case houses in two localities, namely, Kampung Lopeng and Taman Shang Ri La, Miri, Sarawak, respectively. All mosquitoes collected were identified, which consisted of 11 species. Aedes albopictus, both the adult and larval stages, was the dominant species. Resting catch method obtained the highest number of adult mosquitoes (67%), whereas ovitrap showed the highest catch for larval mosquitoes (84%). Zika virus was detected in both adults and larvae of Ae. albopictus together with adults of Culex gelidus, and Culex quinquefasciatus using the real-time reverse transcriptase polymerase chain reaction (PCR) technique. It was noteworthy that Ae. albopictus positive with ZIKV were caught and obtained from four types of collection method. By contrast, Cx. gelidus and Culex quinquefasciatus adults collected from sticky ovitraps were also found positive with ZIKV. This study reveals vital information regarding the potential vectors of ZIKV and the possibility of transovarian transmission of the virus in Malaysia. These findings will be essentials for vector control program managers to devise preparedness and contingency plans of prevention and control of the arboviral disease.
    Matched MeSH terms: Culicidae/virology*
  2. Fulltext Determining the spatial autocorrelation of dengue vector populations: influences of mosquito sampling method, covariables, and vector control
    Azil AH, Bruce D, Williams CR
    J Vector Ecol, 2014 Jun;39(1):153-63.
    PMID: 24820568 DOI: 10.1111/j.1948-7134.2014.12082.x
    We investigated spatial autocorrelation of female Aedes aegypti L. mosquito abundance from BG-Sentinel trap and sticky ovitrap collections in Cairns, north Queensland, Australia. BG-Sentinel trap collections in 2010 show a significant spatial autocorrelation across the study site and over a smaller spatial extent, while sticky ovitrap collections only indicate a non-significant, weak spatial autocorrelation. The BG-Sentinel trap collections were suitable for spatial interpolation using ordinary kriging and cokriging techniques. The uses of Premise Condition Index and potential breeding container data have helped improve our prediction of vector abundance. Semiovariograms and prediction maps indicate that the spatial autocorrelation of mosquito abundance determined by BG-Sentinel traps extends farther compared to sticky ovitrap collections. Based on our data, fewer BG-Sentinel traps are required to represent vector abundance at a series of houses compared to sticky ovitraps. A lack of spatial structure was observed following vector control treatment in the area. This finding has implications for the design and costs of dengue vector surveillance programs.
    Matched MeSH terms: Culicidae/virology
  3. Fulltext An update on the mosquito fauna and mosquito-borne diseases distribution in Cameroon
    Bamou R, Mayi MPA, Djiappi-Tchamen B, Nana-Ndjangwo SM, Nchoutpouen E, Cornel AJ, et al.
    Parasit Vectors, 2021 Oct 11;14(1):527.
    PMID: 34635176 DOI: 10.1186/s13071-021-04950-9
    The expansion of mosquito-borne diseases such as dengue, yellow fever, and chikungunya in the past 15 years has ignited the need for active surveillance of common and neglected mosquito-borne infectious diseases. The surveillance should be designed to detect diseases and to provide relevant field-based data for developing and implementing effective control measures to prevent outbreaks before significant public health consequences can occur. Mosquitoes are important vectors of human and animal pathogens, and knowledge on their biodiversity and distribution in the Afrotropical region is needed for the development of evidence-based vector control strategies. Following a comprehensive literature search, an inventory of the diversity and distribution of mosquitoes as well as the different mosquito-borne diseases found in Cameroon was made. A total of 290 publications/reports and the mosquito catalogue website were consulted for the review. To date, about 307 species, four subspecies and one putative new species of Culicidae, comprising 60 species and one putative new species of Anopheles, 67 species and two subspecies of Culex, 77 species and one subspecies of Aedes, 31 species and one subspecies of Eretmapodites, two Mansonia, eight Coquillettidia, and 62 species with unknown medical and veterinary importance (Toxorhynchites, Uranotaenia, Mimomyia, Malaya, Hodgesia, Ficalbia, Orthopodomyia, Aedeomyia, and Culiseta and Lutzia) have been collected in Cameroon. Multiple mosquito species implicated in the transmission of pathogens within Anopheles, Culex, Aedes, Eretmapodites, Mansonia, and Coquillettidia have been reported in Cameroon. Furthermore, the presence of 26 human and zoonotic arboviral diseases, one helminthic disease, and two protozoal diseases has been reported. Information on the bionomics, taxonomy, and distribution of mosquito species will be useful for the development of integrated vector management programmes for the surveillance and elimination of mosquito-borne diseases in Cameroon.
    Matched MeSH terms: Culicidae/virology
  4. Feeding behavior of Mimomyia (Etorleptiomyia) luzonensis (Ludlow, 1905) (Diptera, Culicidae) in Peninsular Malaysia
    Braima KA, Muslimin M, M Ghazali AR, Wan-Nor F, Wilson JJ, Jeffery J, et al.
    Acta Trop, 2017 Jul;171:138-140.
    PMID: 28359829 DOI: 10.1016/j.actatropica.2017.03.025
    Mosquitoes are vectors of various human diseases in the tropics including yellow fever, dengue, malaria and West Nile virus. Mosquitoes can act as vectors between wildlife and humans, which is particularly important for diseases where wild animals serve as reservoirs of parasites in the absence of human infections. Research has mainly focused on the medical impacts of Anopheles, Aedes, Mansonia and Culex, however, very little attention has been directed towards other mosquito genera, especially those which act as vectors of diseases of wildlife. We have observed adults of Mimomyia (Etorleptiomyia) luzonensis (Ludlow, 1905) feeding on a toad, Ingerophrynus parvus, near an oil palm plantation settlement in Setia Alam, Selangor state, Peninsular Malaysia. Mimomyia is known to feed on reptiles and amphibians, and is a documented vector of several arboviruses, including West Nile virus. The observation of Mimomyia feeding on a common toad near a human settlement highlights a need to understand the relationships between mosquitoes, toads and humans from an ecological perspective. We report on-site observations of the feeding habit of Mimomyia; the first records from Malaysia.
    Matched MeSH terms: Culicidae/virology
  5. Fulltext Detection and serotyping of dengue viruses by PCR: a simple, rapid method for the isolation of viral RNA from infected mosquito larvae
    Chan SY, Kautner I, Lam SK
    Southeast Asian J. Trop. Med. Public Health, 1994 Jun;25(2):258-61.
    PMID: 7855637
    Dengue viruses pose a considerable global public health problem with an estimated 100 million cases of illness every year. This illustrates the need for rapid and reliable diagnostic methods for proper patient management and disease control. Currently, laboratory diagnosis depends on serology or virus isolation, with both methods having certain drawbacks. Alternatively, reverse transcription and polymerase chain reaction (RT-PCR) offers the potential for the rapid, highly sensitive and specific detection of dengue viruses. Since we occasionally encounter the problem of insufficient amounts of patient serum for the direct detection of dengue viruses, a method was developed for the extraction of viral RNA after biological amplification in mosquito larvae. Using this method, 15 of 19 clinical samples tested were correctly identified using RT-PCR.
    Matched MeSH terms: Culicidae/virology*
  6. Identification of a 48kDa tubulin or tubulin-like C6/36 mosquito cells protein that binds dengue virus 2 using mass spectrometry
    Chee HY, AbuBakar S
    Biochem Biophys Res Commun, 2004 Jul 16;320(1):11-7.
    PMID: 15207695
    Binding of dengue virus 2 (DENV-2) to C6/36 mosquito cells protein was investigated. A 48 kDa DENV-2-binding C6/36 cells protein (D2BP) was detected in a virus overlay protein-binding assay. The binding occurred only to the C6/36 cells cytosolic protein fraction and it was inhibited by free D2BP. D2BP was shown to bind to DENV-2 E in the far-Western-binding studies and using mass spectrometry (MS) and MS/MS, peptide masses of the D2BP that matched to beta-tubulin and alpha-tubulin chains were identified. These findings suggest that DENV-2 through DENV-2 E binds directly to a 48 kDa tubulin or tubulin-like protein of C6/36 mosquito cells.
    Matched MeSH terms: Culicidae/virology*
  7. Fulltext The interplay of climate, intervention and imported cases as determinants of the 2014 dengue outbreak in Guangzhou
    Cheng Q, Jing Q, Spear RC, Marshall JM, Yang Z, Gong P
    PLoS Negl Trop Dis, 2017 Jun;11(6):e0005701.
    PMID: 28640895 DOI: 10.1371/journal.pntd.0005701
    Dengue is a fast spreading mosquito-borne disease that affects more than half of the population worldwide. An unprecedented outbreak happened in Guangzhou, China in 2014, which contributed 52 percent of all dengue cases that occurred in mainland China between 1990 and 2015. Our previous analysis, based on a deterministic model, concluded that the early timing of the first imported case that triggered local transmission and the excessive rainfall thereafter were the most important determinants of the large final epidemic size in 2014. However, the deterministic model did not allow us to explore the driving force of the early local transmission. Here, we expand the model to include stochastic elements and calculate the successful invasion rate of cases that entered Guangzhou at different times under different climate and intervention scenarios. The conclusion is that the higher number of imported cases in May and June was responsible for the early outbreak instead of climate. Although the excessive rainfall in 2014 did increase the success rate, this effect was offset by the low initial water level caused by interventions in late 2013. The success rate is strongly dependent on mosquito abundance during the recovery period of the imported case, since the first step of a successful invasion is infecting at least one local mosquito. The average final epidemic size of successful invasion decreases exponentially with introduction time, which means if an imported case in early summer initiates the infection process, the final number infected can be extremely large. Therefore, dengue outbreaks occurring in Thailand, Singapore, Malaysia and Vietnam in early summer merit greater attention, since the travel volumes between Guangzhou and these countries are large. As the climate changes, destroying mosquito breeding sites in Guangzhou can mitigate the detrimental effects of the probable increase in rainfall in spring and summer.
    Matched MeSH terms: Culicidae/virology
  8. Fulltext Characterization of Three New Insect-Specific Flaviviruses: Their Relationship to the Mosquito-Borne Flavivirus Pathogens
    Guzman H, Contreras-Gutierrez MA, Travassos da Rosa APA, Nunes MRT, Cardoso JF, Popov VL, et al.
    Am J Trop Med Hyg, 2018 02;98(2):410-419.
    PMID: 29016330 DOI: 10.4269/ajtmh.17-0350
    Three novel insect-specific flaviviruses, isolated from mosquitoes collected in Peru, Malaysia (Sarawak), and the United States, are characterized. The new viruses, designated La Tina, Kampung Karu, and Long Pine Key, respectively, are antigenically and phylogenetically more similar to the mosquito-borne flavivirus pathogens, than to the classical insect-specific viruses like cell fusing agent and Culex flavivirus. The potential implications of this relationship and the possible uses of these and other arbovirus-related insect-specific flaviviruses are reviewed.
    Matched MeSH terms: Culicidae/virology*
  9. The genetic characteristics and evolution of Tembusu virus
    Lei W, Guo X, Fu S, Feng Y, Tao X, Gao X, et al.
    Vet Microbiol, 2017 Mar;201:32-41.
    PMID: 28284620 DOI: 10.1016/j.vetmic.2017.01.003
    BACKGROUND: Since the turn of the 21st century, there have been several epidemic outbreaks of poultry diseases caused by Tembusu virus (TMUV). Although multiple mosquito and poultry-derived strains of TMUV have been isolated, no data exist about their comparative study, origin, evolution, and dissemination.

    METHODOLOGY: Parallel virology was used to investigate the phenotypes of duck and mosquito-derived isolates of TMUV. Molecular biology and bioinformatics methods were employed to investigate the genetic characteristics and evolution of TMUV.

    PRINCIPAL FINDINGS: The plaque diameter of duck-derived isolates of TMUV was larger than that of mosquito-derived isolates. The cytopathic effect (CPE) in mammalian cells occurred more rapidly induced by duck-derived isolates than by mosquito-derived isolates. Furthermore, duck-derived isolates required less time to reach maximum titer, and exhibited higher viral titer. These findings suggested that poultry-derived TMUV isolates were more invasive and had greater expansion capability than the mosquito-derived isolates in mammalian cells. Variations in amino acid loci in TMUV E gene sequence revealed two mutated amino acid loci in strains isolated from Malaysia, Thailand, and Chinese mainland compared with the prototypical strain of the virus (MM1775). Furthermore, TMUV isolates from the Chinese mainland had six common variations in the E gene loci that differed from the Southeast Asian strains. Phylogenetic analysis indicated that TMUV did not exhibit a species barrier in avian species and consisted of two lineages: the Southeast Asian and the Chinese mainland lineages. Molecular traceability studies revealed that the recent common evolutionary ancestor of TMUV might have appeared before 1934 and that Malaysia, Thailand and Shandong Province of China represent the three main sources related to TMUV spread.

    CONCLUSIONS: The current broad distribution of TMUV strains in Southeast Asia and Chinese mainland exhibited longer-range diffusion and larger-scale propagation. Therefore, in addition to China, other Asian and European countries linked to Asia have used improved measures to detect and monitor TMUV related diseases to prevent epidemics in poultry.

    Matched MeSH terms: Culicidae/virology*
  10. Fulltext Identification of a Newly Isolated Getah Virus in the China-Laos Border, China
    Li YY, Fu SH, Guo XF, Lei WW, Li XL, Song JD, et al.
    Biomed Environ Sci, 2017 Mar;30(3):210-214.
    PMID: 28427491 DOI: 10.3967/bes2017.028
    In this study, we isolated a virus strain (YN12031) from specimens of Armigeres subalbatus collected in the China-Laos border. BHK-21 cells infected with YN12031 exhibited an evident cytopathic effect (CPE) 32 h post-infection. The virus particles were spherical, 70 nm in diameter, and enveloped; they also featured surface fibers. Molecular genetic analysis revealed that YN12031 was closely related to alpha viruses such as Chikungunya virus and Sindbis virus, and located in the same clade as MM2021, the prototype of Getahvirus (GETV) isolated in Malaysia in 1955. Phylogenetic analysis of the E2 and capsid genes further revealed that YN12031 was located in the same clade as the Russian isolate LEIV/16275/Mag. Analysis of the homology of nucleotides and amino acids in the coding area and E2 gene demonstrated that the YN12031 isolated from the China-Laos border (tropical region) was related closest to the LEIV/16275/Mag isolate obtained in Russia (North frigid zone area) among other isolates studied. These results suggest that GETV can adapt to different geographical environments to propagate and evolve. Thus, strengthening the detection and monitoring of GETV and its related diseases is very crucial.
    Matched MeSH terms: Culicidae/virology*
  11. Aptamers isolated against mosquito-borne pathogens
    Navien TN, Yeoh TS, Anna A, Tang TH, Citartan M
    World J Microbiol Biotechnol, 2021 Jul 09;37(8):131.
    PMID: 34240263 DOI: 10.1007/s11274-021-03097-0
    Mosquito-borne diseases are a major threat to public health. The shortcomings of diagnostic tools, especially those that are antibody-based, have been blamed in part for the rising annual morbidity and mortality caused by these diseases. Antibodies harbor a number of disadvantages that can be clearly addressed by aptamers as the more promising molecular recognition elements. Aptamers are defined as single-stranded DNA or RNA oligonucleotides generated by SELEX that exhibit high binding affinity and specificity against a wide variety of target molecules based on their unique structural conformations. A number of aptamers were developed against mosquito-borne pathogens such as Dengue virus, Zika virus, Chikungunya virus, Plasmodium parasite, Francisella tularensis, Japanese encephalitis virus, Venezuelan equine encephalitis virus, Rift Valley fever virus and Yellow fever virus. Intrigued by these achievements, we carry out a comprehensive overview of the aptamers developed against these mosquito-borne infectious agents. Characteristics of the aptamers and their roles in diagnostic, therapeutic as well as other applications are emphasized.
    Matched MeSH terms: Culicidae/virology
  12. Fulltext Cross-sectional serosurvey for Japanese encephalitis specific antibody from animal sera in Malaysia 1993
    Oda K, Igarashi A, Kheong CT, Hong CC, Vijayamalar B, Sinniah M, et al.
    Southeast Asian J. Trop. Med. Public Health, 1996 Sep;27(3):463-70.
    PMID: 9185254
    Serum specimens were collected from 6 species of animals living in 9 states of Malaysia including Sabah, North Borneo in 1993. Antibodies against Japanese encephalitis (JE) virus in these sera were detected by means of hemagglutination-inhibition (HI) and neutralization (NT) tests. By HI test, 702 of 2,152 (32.6%) sera showed positive results. Higher positive rates were obtained by the NT test, in which 1,787 of 1,927 (92.7%) sera had antibodies against JE virus. All serum specimens with positive HI were confirmed as positive by the NT. Swine sera showed especially higher rates of antibody positive and higher antibody titers compared with other animals. These results suggest that JE infections are widely distributed among many animals of Malaysia, and pig is the most susceptible amplifier host for JE virus.
    Matched MeSH terms: Culicidae/virology
  13. Fulltext Temperature related storage evaluation of an RT-PCR test kit for the detection of dengue infection in mosquitoes
    Ooi CP, Rohani A, Zamree I, Lee HL
    Trop Biomed, 2005 Jun;22(1):73-6.
    PMID: 16880757
    The rapid detection of dengue infection in mosquito vectors is important for early warning to forestall an outbreak. Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) provides a rapid method for dengue detection in man and mosquitoes. An RT-PCR kit developed by the Medical Entomology Unit, Institute for Medical Research to detect dengue infection in mosquitoes, was tested for its shelf life at 3 storage temperatures: room temperature, refrigerator and freezer. Test kits were tested once every 3 days for kits stored at room temperature, and once every week for those stored at refrigerator and freezer temperatures. The results showed that the test kit could only be stored above its recommended storage temperature of -20 degrees C for not more than 3 days. DNA 100 bp markers in the kits appeared to be stable at the tested temperatures and were usable up to the 20th day when stored at 2 degrees C and below.
    Matched MeSH terms: Culicidae/virology*
  14. Fulltext Entomological study of chikungunya infections in the State of Kelantan, Malaysia
    Rozilawati H, Faudzi AY, Rahidah AA, Azlina AH, Abdullah AG, Amal NM, et al.
    Indian J Med Res, 2011 Jun;133:670-3.
    PMID: 21727669
    Chikungunya infection has become a public health threat in Malaysia since the 2008 nationwide outbreaks. Aedes albopictus Skuse has been identified as the chikungunya vector in Johor State during the outbreaks. In 2009, several outbreaks had been reported in the State of Kelantan. Entomological studies were conducted in Kelantan in four districts, namely Jeli, Tumpat, Pasir Mas and Tanah Merah to identify the vector responsible for the virus transmission.
    Matched MeSH terms: Culicidae/virology*
  15. Fulltext Genomes of viral isolates derived from different mosquitos species
    Sadeghi M, Popov V, Guzman H, Phan TG, Vasilakis N, Tesh R, et al.
    Virus Res, 2017 10 15;242:49-57.
    PMID: 28855097 DOI: 10.1016/j.virusres.2017.08.012
    Eleven viral isolates derived mostly in albopictus C6/36 cells from mosquito pools collected in Southeast Asia and the Americas between 1966 and 2014 contained particles with electron microscopy morphology typical of reoviruses. Metagenomics analysis yielded the near complete genomes of three novel reoviruses, Big Cypress orbivirus, Ninarumi virus, and High Island virus and a new tetravirus, Sarawak virus. Strains of previously characterized Sathuvarachi, Yunnan, Banna and Parry's Lagoon viruses (Reoviridae), Bontang virus (Mesoniviridae), and Culex theileri flavivirus (Flaviviridae) were also characterized. The availability of these mosquito virus genomes will facilitate their detection by metagenomics or PCR to better determine their geographic range, extent of host tropism, and possible association with arthropod or vertebrate disease.
    Matched MeSH terms: Culicidae/virology*
  16. Fulltext Genotypic and phenotypic characterization of Chikungunya virus of different genotypes from Malaysia
    Sam IC, Loong SK, Michael JC, Chua CL, Wan Sulaiman WY, Vythilingam I, et al.
    PLoS One, 2012;7(11):e50476.
    PMID: 23209750 DOI: 10.1371/journal.pone.0050476
    Mosquito-borne Chikungunya virus (CHIKV) has recently re-emerged globally. The epidemic East/Central/South African (ECSA) strains have spread for the first time to Asia, which previously only had endemic Asian strains. In Malaysia, the ECSA strain caused an extensive nationwide outbreak in 2008, while the Asian strains only caused limited outbreaks prior to this. To gain insight into these observed epidemiological differences, we compared genotypic and phenotypic characteristics of CHIKV of Asian and ECSA genotypes isolated in Malaysia.
    Matched MeSH terms: Culicidae/virology
  17. 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: Culicidae/virology*
  18. Neurovirulence and host factors in flavivirus encephalitis--evidence from clinical epidemiology
    Solomon T, Winter PM
    Arch. Virol. Suppl., 2004.
    PMID: 15119771
    Japanese encephalitis virus (JEV) and West Nile virus (WNV) provide some of the most important examples of emerging zoonotic viral encephalitides. For these flaviviruses, only a small proportion of those infected develop clinical features, and these may range from a non-specific flu-like illness to a severe fatal meningoencephalitis, often with Parkinsonian features, or a poliomyelitis-like flaccid paralysis. The factors governing the clinical presentations, and outcome of flavivirus infections are poorly understood, but studies have looked at viral virulence determinants and the host immune response. Previous studies on JEV have suggested that the distribution of the four genotypes across Asia may relate to the differing clinical epidemiology (epidemic disease in the north, endemic disease in the south). However, new data based on the complete nucleotide sequence of a virus representing one of the oldest lineages, and phylogenetic analyses of all JEV strains for which genetic data are available, suggest that the distribution is best explained in terms of the virus' origin in the Indonesia-Malaysia region (where all genotypes have been found), and the spread of the more recent genotypes to new geographical areas. Clinical studies have shown that innate immunity, as manifested by interferon alpha levels, is important in JEV and other flaviviruses, but treatment with interferon alpha did not improve the outcome. A failure of the humoral immune response, is associated with death from encephalitis caused by JEV and WNV. Cellular immunity has been less well characterized, but CD8+ and CD4+ T cells are thought to be important.
    Matched MeSH terms: Culicidae/virology*
  19. Molecular Epidemiology of Chikungunya Virus by Sequencing
    Thayan R, Yusof MA, Saat Z, Sekaran SD, Wang SM
    Methods Mol Biol, 2016;1426:11-9.
    PMID: 27233257 DOI: 10.1007/978-1-4939-3618-2_2
    Molecular surveillance of Chikungunya virus (CHIKV) is important as it provides data on the circulating CHIKV genotypes in endemic countries and enabling activation of measures to be taken in the event of a pending outbreak. Molecular surveillance is carried out by first detecting CHIKV in susceptible humans or among field-caught mosquitoes. This is followed by sequencing a selected region of the virus which will provide evidence on the source of the virus and possible association of the virus to increased cases of Chikungunya infections.
    Matched MeSH terms: Culicidae/virology*
  20. Genotypes of Japanese encephalitis virus isolated in three states in Malaysia
    Tsuchie H, Oda K, Vythilingam I, Thayan R, Vijayamalar B, Sinniah M, et al.
    Am J Trop Med Hyg, 1997 Feb;56(2):153-8.
    PMID: 9080873
    Two hundred forty nucleotides from the pre-membrane gene region of 12 Japanese encephalitis virus (JEV) strains isolated from three different regions of Malaysia from 1993 to 1994 were sequenced and compared with each other and with the JEV strains from different geographic areas in Asia. These 12 Malaysian isolates were classified into two genotypes. The four JEV strains isolated from Sarawak in 1994 and the four JEV strains isolated from Sepang, Selangor in 1993 were classified into one genotype that included earlier isolated strains from Malaysia (JE-827 from Sarawak in 1968 and WTP/70/22 from Kuala Lumpur in 1970). The four JEV strains from Ipoh, Perak in 1994 were classified into another genotype that included JEV strains isolated from northern Thailand and Cambodia. In an earlier report, 10 JEV strains from Sabak Bernam, Selangor in 1992 were classified into the largest genotype that included strains isolated in temperate regions such as Japan, China, and Taiwan. The data indicate that at least three genotypes of JEV have been circulating in Malaysia.
    Matched MeSH terms: Culicidae/virology
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