Displaying publications 1 - 20 of 193 in total

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  1. Teoh BT, Sam SS, Tan KK, Johari J, Shu MH, Danlami MB, et al.
    BMC Evol. Biol., 2013;13:213.
    PMID: 24073945 DOI: 10.1186/1471-2148-13-213
    Recurring dengue outbreaks occur in cyclical pattern in most endemic countries. The recurrences of dengue virus (DENV) infection predispose the population to increased risk of contracting the severe forms of dengue. Understanding the DENV evolutionary mechanism underlying the recurring dengue outbreaks has important implications for epidemic prediction and disease control.
    Matched MeSH terms: Dengue/epidemiology*
  2. Sam SS, Omar SF, Teoh BT, Abd-Jamil J, AbuBakar S
    PLoS Negl Trop Dis, 2013;7(5):e2194.
    PMID: 23658849 DOI: 10.1371/journal.pntd.0002194
    Dengue is a mosquito-borne viral disease endemic in many countries in the tropics and sub-tropics. The disease affects mainly children, but in recent years it is becoming more of an adult disease. Malaysia experienced a large dengue outbreak in 2006 to 2007, involving mostly adults, with a high number of deaths.
    Matched MeSH terms: Severe Dengue/epidemiology*
  3. Dieng H, Saifur RG, Hassan AA, Salmah MR, Boots M, Satho T, et al.
    PLoS One, 2010;5(7):e11790.
    PMID: 20668543 DOI: 10.1371/journal.pone.0011790
    The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities.
    Matched MeSH terms: Dengue/epidemiology*
  4. Chandren JR, Wong LP, AbuBakar S
    PLoS Negl Trop Dis, 2015;9(8):e0003954.
    PMID: 26267905 DOI: 10.1371/journal.pntd.0003954
    BACKGROUND: Dengue is prevalent among Malaysia's indigenous peoples, known as the Orang Asli, and it poses a serious health threat to them. The study aims to look at the socio-demographic factors, health beliefs, and knowledge about dengue and its association to dengue prevention practices among Orang Asli communities in Peninsular Malaysia.

    METHODS: A cross-sectional survey was conducted in 16 randomly selected Orang Asli villages from eight states in Peninsular Malaysia from April 2012 until February 2013.

    RESULTS: A total of 560 Orang Asli were interviewed and 505 completed the survey. Slightly above half of the participants (n = 280, 55.4%) had a total dengue prevention score of 51-100 (of a possible score of 0-100). Multivariate analysis findings showed dengue knowledge, perceived barriers to perform dengue prevention, fogging frequency, and perceived susceptibility to dengue fever as significant factors associated to dengue prevention practices. Participants with a lower dengue knowledge score (score 0-18) were less likely (OR = 0.63, 95%CI = 0.44-0.92 vs. score 19-36, P = 0.015) to practice dengue prevention. Participants with low perceived barriers to prevent dengue (score of 1-5) were more likely (OR = 2.06, 95%CI = 1.21-3.53, vs. score of 6-10, P = 0.008) to practice dengue prevention. Villages that were not fogged (OR = 0.49, 95%CI = 0.24-0.99, P = 0.045) or rarely fogged (OR = 0.40, 95%CI = 0.22-0.75, P = 0.004) had lower dengue prevention practices than villages that were fogged often. Participants with low perceived susceptibility of acquiring dengue (score of 1-5) were less likely (OR = 0.54, 95%CI = 0.33-0.89 vs. score of 6-10, P = 0.018) to practice dengue prevention measures.

    CONCLUSION: Findings imply that educational and health programmes should focus on enhancing dengue knowledge and perceived susceptibility of acquiring dengue and reducing perceived barriers to performing dengue prevention practices among the Orang Asli. More outreach on mosquito control campaigns should be carried out especially in villages where mosquito fogging is frequent.

    Matched MeSH terms: Dengue/epidemiology
  5. Joanne S, Vythilingam I, Yugavathy N, Leong CS, Wong ML, AbuBakar S
    Acta Trop, 2015 Aug;148:38-45.
    PMID: 25899523 DOI: 10.1016/j.actatropica.2015.04.003
    Wolbachia are maternally transmitted bacteria found in most arthropods and nematodes, but little is known about their distribution and reproductive dynamics in the Malaysian dengue vector Aedes albopictus. In this study, polymerase chain reaction (PCR) was used to determine the presence of Wolbachia from field collected Ae. albopictus from various parts of the country using wsp specific primers. Ae. albopictus had Wolbachia infection ranging from 60 to 100%. No sequence diversity of wsp gene was found within all wAlbA and wAlbB sequences. Our findings suggest that Wolbachia infection amongst the Malaysian Ae. albopictus were not homogenously distributed in all districts in Malaysia. The presence of Wolbachia in different organs of Ae. albopictus was also determined. Wolbachia were only found in the ovaries and midguts of the mosquitoes, while absent in the salivary glands. The effects of Wolbachia on Ae. albopictus fecundity, longevity and egg viability were studied using infected and uninfected colonies. The removal of Wolbachia from Ae. albopictus resulted in reduced fecundity, longevity and egg viability, thus. Wolbachia seem to play a vital role in Ae. albopictus reproductive system.
    Matched MeSH terms: Dengue/epidemiology*
  6. Wong LP, Shakir SM, Atefi N, AbuBakar S
    PLoS One, 2015;10(4):e0122890.
    PMID: 25836366 DOI: 10.1371/journal.pone.0122890
    Efforts to stamp dengue in many dengue endemic countries has met little success. There is a need to re-examine and understand how the public at large view the dengue prevention efforts. This study aimed to examine the demographic factors, theoretical constructs of the Health Belief Model and knowledge about dengue and how these influence the practice of dengue prevention.
    Matched MeSH terms: Dengue/epidemiology*
  7. Tan KK, Zulkifle NI, Sulaiman S, Pang SP, NorAmdan N, MatRahim N, et al.
    BMC Evol. Biol., 2018 04 24;18(1):58.
    PMID: 29699483 DOI: 10.1186/s12862-018-1175-4
    BACKGROUND: Dengue virus type 3 genotype III (DENV3/III) is associated with increased number of severe infections when it emerged in the Americas and Asia. We had previously demonstrated that the DENV3/III was introduced into Malaysia in the late 2000s. We investigated the genetic diversity of DENV3/III strains recovered from Malaysia and examined their phylogenetic relationships against other DENV3/III strains isolated globally.

    RESULTS: Phylogenetic analysis revealed at least four distinct DENV3/III lineages. Two of the lineages (DENV3/III-B and DENV3/III-C) are current actively circulating whereas the DENV3/III-A and DENV3/III-D were no longer recovered since the 1980s. Selection pressure analysis revealed strong evidence of positive selection on a number of amino acid sites in PrM, E, NS1, NS2a, NS2b, NS3, NS4a, and NS5. The Malaysian DENV3/III isolates recovered in the 1980s (MY.59538/1987) clustered into DENV3/III-B, which was the lineage with cosmopolitan distribution consisting of strains actively circulating in the Americas, Africa, and Asia. The Malaysian isolates recovered after the 2000s clustered within DENV3/III-C. This DENV3/III-C lineage displayed a more restricted geographical distribution and consisted of isolates recovered from Asia, denoted as the Asian lineage. Amino acid variation sites in NS5 (NS5-553I/M, NS5-629 T, and NS5-820E) differentiated the DENV3/III-C from other DENV3 viruses. The codon 629 of NS5 was identified as a positively selected site. While the NS5-698R was identified as unique to the genome of DENV3/III-C3. Phylogeographic results suggested that the recent Malaysian DENV3/III-C was likely to have been introduced from Singapore in 2008 and became endemic. From Malaysia, the virus subsequently spread into Taiwan and Thailand in the early part of the 2010s and later reintroduced into Singapore in 2013.

    CONCLUSIONS: Distinct clustering of the Malaysian old and new DENV3/III isolates suggests that the currently circulating DENV3/III in Malaysia did not descend directly from the strains recovered during the 1980s. Phylogenetic analyses and common genetic traits in the genome of the strains and those from the neighboring countries suggest that the Malaysian DENV3/III is likely to have been introduced from the neighboring regions. Malaysia, however, serves as one of the sources of the recent regional spread of DENV3/III-C3 within the Asia region.

    Matched MeSH terms: Dengue/epidemiology
  8. Tan KK, Zulkifle NI, Abd-Jamil J, Sulaiman S, Yaacob CN, Azizan NS, et al.
    Infect Genet Evol, 2017 Oct;54:271-275.
    PMID: 28698156 DOI: 10.1016/j.meegid.2017.07.008
    Dengue is hyperendemic in most of Southeast Asia. In this region, all four dengue virus serotypes are persistently present. Major dengue outbreak cycle occurs in a cyclical pattern involving the different dengue virus serotypes. In Malaysia, since the 1980s, the major outbreak cycles have involved dengue virus type 3 (DENV3), dengue virus type 1 (DENV1) and dengue virus type 2 (DENV2), occurring in that order (DENV3/DENV1/DENV2). Only limited information on the DENV3 cycles, however, have been described. In the current study, we examined the major outbreak cycle involving DENV3 using data from 1985 to 2016. We examined the genetic diversity of DENV3 isolates obtained during the period when DENV3 was the dominant serotype and during the inter-dominant transmission period. Results obtained suggest that the typical DENV3/DENV1/DENV2 cyclical outbreak cycle in Malaysia has recently been disrupted. The last recorded major outbreak cycle involving DENV3 occurred in 2002, and the expected major outbreak cycle involving DENV3 in 2006-2012 did not materialize. DENV genome analyses revealed that DENV3 genotype II (DENV3/II) was the predominant DENV3 genotype (67%-100%) recovered between 1987 and 2002. DENV3 genotype I (DENV3/I) emerged in 2002 followed by the introduction of DENV3 genotype III (DENV3/III) in 2008. These newly emerged DENV3 genotypes replaced DENV3/II, but there was no major upsurge of DENV3 cases that accompanied the emergence of these viruses. DENV3 remained in the background of DENV1 and DENV2 until now. Virus genome sequence analysis suggested that intrinsic differences within the different dengue virus genotypes could have influenced the transmission efficiency of DENV3. Further studies and continuous monitoring of the virus are needed for better understanding of the DENV transmission dynamics in hyperendemic regions.
    Matched MeSH terms: Dengue/epidemiology*
  9. Khor CS, Tsuji R, Lee HY, Nor'e SS, Sahimin N, Azman AS, et al.
    Nutrients, 2021 Dec 16;13(12).
    PMID: 34960061 DOI: 10.3390/nu13124507
    Dengue fever (DF) is a mosquito-borne disease still with no effective treatment or vaccine available. A randomized, placebo-controlled, double-blinded, parallel-group trial was undertaken to evaluate the efficacy of oral intake of Lactococcus lactis strain plasma (LC-Plasma) on the presentation and severity of DF-like symptoms among healthy volunteers. Study participants (320) were assigned into two groups, and consumed either placebo or LC-Plasma tablets (approximately 100 billion cells/day) for 8 weeks. The clinical symptoms of DF were self-recorded through questionnaires, and exposure to DENV was determined by serum antibody and/or DENV antigen tests. No significant differences between groups were observed for exposure to DENV, or the symptomatic ratio. Results obtained showed that participants from the LC-Plasma group reported a significant reduction in the cumulative incidence days of DF-like symptoms, which include fever (p < 0.001), muscle pain (p < 0.005), joint pain (p < 0.001), and pain behind the eyes (p < 0.001), compared to that of the placebo group. Subgroup analysis revealed a significantly (p < 0.05) reduced severity score in the LC-Plasma group when study sites were separately analyzed. Overall, our findings suggest that LC-Plasma supplementation reduces the cumulative days with DF-like symptoms, and the severity of the symptoms. Daily oral intake of LC-Plasma, hence, is shown to mitigate the DF-like symptoms.
    Matched MeSH terms: Dengue/epidemiology
  10. Teoh BT, Sam SS, Abd-Jamil J, AbuBakar S
    Emerg Infect Dis, 2010 Nov;16(11):1783-5.
    PMID: 21029545 DOI: 10.3201/eid1611.100721
    Ancestral sylvatic dengue virus type 1, which was isolated from a monkey in 1972, was isolated from a patient with dengue fever in Malaysia. The virus is neutralized by serum of patients with endemic DENV-1 infection. Rare isolation of this virus suggests a limited spillover infection from an otherwise restricted sylvatic cycle.
    Matched MeSH terms: Dengue/epidemiology*
  11. Wong LP, AbuBakar S
    PLoS Negl Trop Dis, 2013;7(7):e2310.
    PMID: 23875045 DOI: 10.1371/journal.pntd.0002310
    BACKGROUND: This qualitative study aimed to provide an in-depth understanding of the meaning of dengue fever (DF) amongst people living in a dengue endemic region, dengue prevention and treatment-seeking behaviours. The Health Belief Model was used as a framework to explore and understand dengue prevention behaviours.

    METHODS: A total of 14 focus group discussions were conducted with 84 Malaysian citizens of different socio-demographic backgrounds between 16(th) December, 2011 and 12(th) May, 2012.

    RESULTS: The study revealed that awareness about DF and prevention measures were high. The pathophysiology of dengue especially dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) were rarely known; as a result, it was seen as deadly by some but was also perceived as easily curable by others without a basis of understanding. Young adults and elderly participants had a low perception of susceptibility to DF. In general, the low perceived susceptibility emerged as two themes, namely a perceived natural ability to withstand infection and a low risk of being in contact with the dengue virus vector, Aedes spp. mosquitoes. The barriers to sustained self-prevention against dengue prevention that emerged in focus groups were: i) lack of self-efficacy, ii) lack of perceived benefit, iii) low perceived susceptibility, and iv) unsure perceived susceptibility. Low perceived benefit of continued dengue prevention practices was a result of lack of concerted action against dengue in their neighborhood. Traditional medical practices and home remedies were widely perceived and experienced as efficacious in treating DF.

    CONCLUSION: Behavioural change towards attaining sustainability in dengue preventive practices may be enhanced by fostering comprehensive knowledge of dengue and a change in health beliefs. Wide use of unconventional therapy for DF warrants the need to enlighten the public to limit their reliance on unproven alternative treatments.

    Matched MeSH terms: Dengue/epidemiology*
  12. Wong SS, Abd-Jamil J, Abubakar S
    Viral Immunol, 2007 Sep;20(3):359-68.
    PMID: 17931106
    Outbreaks involving dengue viruses (DENV) of the same genotype occur in a cyclical pattern in Malaysia. Two cycles of outbreaks involving dengue virus type 2 (DENV-2) of the same genotype occurred in the 1990s in the Klang Valley, Malaysia. Sera of patients from the first outbreak and sera of mice inoculated with virus from the same outbreak had poorer neutralization activity against virus of the second outbreak. Conversely, patient sera from the second outbreak showed higher neutralization titer against virus of the early outbreak. At subneutralizing concentrations, sera of mice immunized with second outbreak virus did not significantly enhance infection with viruses from the earlier outbreak. Amino acid substitution from valine to isoleucine at position 129 of the envelope protein (E), as well as threonine to alanine at position 117 and lysine to arginine at position 272 of the NS1 protein, differentiated viruses of the two outbreaks. These findings highlight the potential influence of specific intragenotypic variations in eliciting varied host immune responses against the different DENV subgenotypes. This could be an important contributing factor in the recurring homogenotypic dengue virus outbreaks seen in dengue-endemic regions.
    Matched MeSH terms: Dengue/epidemiology*
  13. Khor CS, Mohd-Rahim NF, Hassan H, Tan KK, Zainal N, Teoh BT, et al.
    J Med Virol, 2020 08;92(8):956-962.
    PMID: 31814135 DOI: 10.1002/jmv.25649
    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: Dengue/epidemiology*
  14. Abir T, Ekwudu O, Kalimullah NA, Nur-A Yazdani DM, Al Mamun A, Basak P, et al.
    PLoS One, 2021;16(3):e0249135.
    PMID: 33784366 DOI: 10.1371/journal.pone.0249135
    Dengue, the most important mosquito-borne viral disease of humans is a recurring global health problem. In Bangladesh, dengue outbreaks are on the increase despite the efforts of government and it is not clear what the understanding of the general Dhaka population towards dengue fever is. Knowledge, attitude and practice (KAP) studies are essential guides in public health interventions. Hence, using KAP, this study aims to assess patient-perspectives with regards to factors associated with dengue, as well as investigate the associated factors between the two corporations in Dhaka. A Hospital-based cross-sectional study of 242 fever patients from two city-corporations in Dhaka (Dhaka North City Corporations, DNCC (n = 91, 37.6%) and Dhaka South City Corporation, DSCC (n = 151, 62.4%) was conducted using pre-tested KAP items. Wilcoxon's Rank Sum was used to determine the KAP by DNCC, DSCC and both corporations and multivariate Poisson regression analyses. The two corporations were analysed separately due to the differences in income distribution, concentration of slums, hospitals and clinics. The study found that more than half of the study population were knowledgeable about dengue (mean percentage scores was 52%), possess an appropriate and acceptable attitude towards the disease (69.2%), and about two thirds of the respondents (71.4%) engaged in practices towards its prevention. After adjusting for the potential cofounders, the factors associated with KAP about dengue fever varied between DNCC and DSCC; with duration of residency and use of mosquito nets were associated with knowledge in the north while income class and age were associated with knowledge and attitude in the south. In the pooled analysis (combining both corporations), knowledge of dengue was associated with good practice towards dengue fever among the respondents. The duration of residence in Dhaka (10+ years), not using mosquito nets and length of time spent in the hospital (7+ days) due to dengue, and decreased knowledge (Adjusted coefficient (β) = -0.01, 95%CI: -0.02, -0.01) were associated with attitude towards dengue in DNCC. On the other hand, middle-high income class, age (40+ years) and increased knowledge were associated with practice towards dengue in DSCC (β = 0.02, 95%CI: 0.01, 0.03). Efforts to increase knowledge about dengue fever through education by the administrations of both corporations would benefit from targeting these high-risk groups for a more sustainable outcome.
    Matched MeSH terms: Dengue/epidemiology*
  15. Gan SJ, Leong YQ, Bin Barhanuddin MFH, Wong ST, Wong SF, Mak JW, et al.
    Parasit Vectors, 2021 Jun 10;14(1):315.
    PMID: 34112220 DOI: 10.1186/s13071-021-04785-4
    Dengue fever is the most important mosquito-borne viral disease in Southeast Asia. Insecticides remain the most effective vector control approach for Aedes mosquitoes. Four main classes of insecticides are widely used for mosquito control: organochlorines, organophosphates, pyrethroids and carbamates. Here, we review the distribution of dengue fever from 2000 to 2020 and its associated mortality in Southeast Asian countries, and we gather evidence on the trend of insecticide resistance and its distribution in these countries since 2000, summarising the mechanisms involved. The prevalence of resistance to these insecticides is increasing in Southeast Asia, and the mechanisms of resistance are reported to be associated with target site mutations, metabolic detoxification, reduced penetration of insecticides via the mosquito cuticle and behavioural changes of mosquitoes. Continuous monitoring of the status of resistance and searching for alternative control measures will be critical for minimising any unpredicted outbreaks and improving public health. This review also provides improved insights into the specific use of insecticides for effective control of mosquitoes in these dengue endemic countries.
    Matched MeSH terms: Dengue/epidemiology*
  16. Kaur N, Rahim SSSA, Jaimin JJ, Dony JJF, Khoon KT, Ahmed K
    J Physiol Anthropol, 2020 Aug 14;39(1):19.
    PMID: 32795350 DOI: 10.1186/s40101-020-00230-0
    BACKGROUND: Malaysia recorded the highest number of dengue cases between 2014 and 2017. There are 13 states and three federal territories in Malaysia, and each area varies in their prevalence of dengue. Sabah is one of the states situated in Borneo, Malaysia. Although dengue has been increasing for the last several years, no study was being done to understand the burden and serotype distribution of the dengue virus (DENV) in Sabah. Therefore, the present study was carried out to understand the epidemiology of the dengue infection and the factors responsible for severe dengue in Sabah.

    METHODS: Data on dengue infection were extracted from the dengue database of the state of Sabah from 2013 through 2018. DENV NS-1-positive serum samples from multiple sites throughout Sabah were sent to the state public health laboratory, Kota Kinabalu Public Health Laboratory, for serotype determination. The analysis of factors associated with severe dengue was determined from the data of 2018 only.

    RESULTS: In 2013, there were 724 dengue cases; however, from 2014, dengue cases increased exponentially and resulted in 3423 cases in 2018. Increasing dengue cases also led to increased dengue mortality. The number of dengue deaths in 2013 was only five which then gradually increased, and in 2018, 29 patients died. This is an increase of 580% from 2013 to 2018. Deaths were considerably more in the districts of the east coast of Sabah compared with districts in the west coast. During the study period, all DENV serotypes could be identified as serotypes circulating in Sabah. In 2018, the predominant serotype was DENV-3. The monthly peak of dengue infection varied in different years. In the logistic regression analysis, it was identified that children were 6.5 times, patients infected with mixed serotype of DENV were 13 times, and cases from the districts of the east coast were 5.2 times more likely to develop severe dengue.

    CONCLUSIONS: An increasing trend of dengue infection has been observed in Sabah. The burden of dengue, severe dengue, and mortality was noted especially in the districts of the east coast of Sabah. Severe dengue was most likely developed in children, cases from the east coast, and patients infected with mixed serotype of DENV.

    Matched MeSH terms: Severe Dengue/epidemiology*
  17. Dhanoa A, Hassan SS, Jahan NK, Reidpath DD, Fatt QK, Ahmad MP, et al.
    Infect Dis Poverty, 2018 Jan 16;7(1):1.
    PMID: 29335021 DOI: 10.1186/s40249-017-0384-1
    BACKGROUND: The frequency and magnitude of dengue epidemics continue to increase exponentially in Malaysia, with a shift in the age range predominance toward adults and an expansion to rural areas. Despite this, information pertaining to the extent of transmission of dengue virus (DENV) in the rural community is lacking. This community-based pilot study was conducted to establish DENV seroprevalence amongst healthy adults in a rural district in Southern Malaysia, and to identify influencing factors.

    METHODS: In this study undertaken between April and May 2015, a total of 277 adult participants were recruited from households across three localities in the Sungai Segamat subdistrict in Segamat district. Sera were tested for immunoglobulin G (IgG) (Panbio® Dengue Indirect IgG ELISA/high-titer capture) and immunoglobulin M (IgM) (Panbio®) antibodies. The plaque reduction neutralization test (PRNT) was conducted on random samples of IgG-positive sera for further confirmation. Medical history and a recall of previous history of dengue were collected through interviews, whereas sociodemographic information was obtained from an existing database.

    RESULTS: The overall seroprevalence for DENV infection was 86.6% (240/277) (95% CI: 83-91%). Serological evidence of recent infection (IgM/high-titer capture IgG) was noted in 11.2% (31/277) of participants, whereas there was evidence of past infection in 75.5% (209/277) of participants (indirect IgG minus recent infections). The PRNT assay showed that the detected antibodies were indeed specific to DENV. The multivariate analysis showed that the older age group was significantly associated with past DENV infections. Seropositivity increased with age; 48.5% in the age group of <25 years to more than 85% in age group of >45 years (P 

    Matched MeSH terms: Dengue/epidemiology*
  18. Pang T, Gubler D, Goh DYT, Ismail Z, Asia Dengue Vaccine Advocacy Group
    Lancet, 2018 02 17;391(10121):654.
    PMID: 29617262 DOI: 10.1016/S0140-6736(18)30245-9
    Matched MeSH terms: Dengue/epidemiology
  19. Thiruchelvam L, Dass SC, Zaki R, Yahya A, Asirvadam VS
    Geospat Health, 2018 05 07;13(1):613.
    PMID: 29772882 DOI: 10.4081/gh.2018.613
    This study investigated the potential relationship between dengue cases and air quality - as measured by the Air Pollution Index (API) for five zones in the state of Selangor, Malaysia. Dengue case patterns can be learned using prediction models based on feedback (lagged terms). However, the question whether air quality affects dengue cases is still not thoroughly investigated based on such feedback models. This work developed dengue prediction models using the autoregressive integrated moving average (ARIMA) and ARIMA with an exogeneous variable (ARIMAX) time series methodologies with API as the exogeneous variable. The Box Jenkins approach based on maximum likelihood was used for analysis as it gives effective model estimates and prediction. Three stages of model comparison were carried out for each zone: first with ARIMA models without API, then ARIMAX models with API data from the API station for that zone and finally, ARIMAX models with API data from the zone and spatially neighbouring zones. Bayesian Information Criterion (BIC) gives goodness-of-fit versus parsimony comparisons between all elicited models. Our study found that ARIMA models, with the lowest BIC value, outperformed the rest in all five zones. The BIC values for the zone of Kuala Selangor were -800.66, -796.22, and -790.5229, respectively, for ARIMA only, ARIMAX with single API component and ARIMAX with API components from its zone and spatially neighbouring zones. Therefore, we concluded that API levels, either temporally for each zone or spatio- temporally based on neighbouring zones, do not have a significant effect on dengue cases.
    Matched MeSH terms: Dengue/epidemiology*
  20. Rong LS, Ann AT, Ahmad NW, Lim LH, Azirun MS
    PMID: 23082552
    Biweekly ovitrap surveillance (OS) was conducted for a year (August 2007 - September 2008) at two different dengue endemic sites in Shah Alam, Selangor, Malaysia, 50 km from Kuala Lumpur. Aedes aegypti collected from these 2 locations were raised to the F3 stage and subjected to a WHO standard bioassay method to determine lethal time (LT) against pyrethroids (permethrin 0.75%, cyfluthrin 0.15%), organophosphates (malathion 5.0%, fenitrothion 1.0%), carbamates (propoxur 0.1%, bendiocarb 0.1%) and organochlorine (DDT 4.0%). Insecticide susceptibilities were analyzed for one year. Aedes aegypti were resistant to DDT with a mortality range of 0 - 13.3% throughout the year at both sites. Susceptibilities to pyrethroids and carbamates varied throughout the year. In contrast, susceptibilities to pyrethroids and carbamates varied throughout the year: resistant to propoxur, bendiocarb and permethrin with mortality of < 80% in most months; but, showed incipient resistant to cyfluthrin in most months. Mosquitoes were consistently susceptible to malathion and fenitrothion, with complete mortality during most months. They were especially susceptible to malathion with LT50 values of 21.32 - 36.37 minutes, suggesting effectiveness of malathion for control of dengue.
    Matched MeSH terms: Dengue/epidemiology
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