Displaying publications 241 - 260 of 685 in total

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  1. Influenza B outbreak in female psychiatric ward of Hospital Kuala Lumpur, Malaysia
    Mohamad Isa MF, Tan JM, Abdul Aziz MF, Leong CL
    Med J Malaysia, 2018 12;73(6):405-406.
    PMID: 30647214
    Influenza outbreaks in tropical countries are rarely reported. This article reports four cases of influenza within a psychiatric ward of a tertiary hospital in Malaysia. These were patients with severe mental illness who were involuntarily admitted and did not show the classical triad of influenza-like-illness (ILI) at the beginning. However, severe respiratory complications developed requiring intubation. Referral and cooperation with the infectious disease team was initiated to help manage the outbreak while continuing psychiatric treatment. Incidences of influenza among hospitalised psychiatric patients should be treated seriously with immediate multidisciplinary approach to prevent severe unwanted complications.
    Matched MeSH terms: Disease Outbreaks*
  2. Fulltext Bonuses and pitfalls of a paperless drive-through screening and COVID-19: A field report
    Lee E, Mohd Esa NY, Wee TM, Soo CI
    J Microbiol Immunol Infect, 2021 Feb;54(1):85-88.
    PMID: 32474025 DOI: 10.1016/j.jmii.2020.05.011
    As the world witnessed the rapid spread of SARS-CoV-2, the World Health Organization has called for governing bodies worldwide to intensify case findings, contact tracing, monitoring, and quarantine or isolation of contacts with COVID-19. Drive-through (DT) screening is a form of case detection which has recently gain preference globally. Proper implementation of this system can help remediate the outbreak.
    Matched MeSH terms: Disease Outbreaks/prevention & control
  3. Fulltext Psychological and Livelihood Impacts of COVID-19 on Bangladeshi Lower Income People
    Paul A, Nath TK, Mahanta J, Sultana NN, Kayes ASMI, Noon SJ, et al.
    Asia Pac J Public Health, 2021 01;33(1):100-108.
    PMID: 33289393 DOI: 10.1177/1010539520977304
    The objective of this research is to understand the psychological and livelihood-related impacts of coronavirus disease 2019 (COVID-19) on Bangladeshi lower income group people who depend on daily earnings for their living. Following the convenience sampling method, 576 respondents were interviewed for quantitative data and 30 in-depth interviews for qualitative information in several districts of Bangladesh. To 94.1% respondents, livelihood has been affected by the COVID-19 outbreak with an overall score of 3.20 ± 0.77 on a 4-point Likert-type scale. In comparison to unemployed respondents, daily workers have been hardly affected by the COVID-19 outbreak (odds ratio [OR] = 7.957; P < .01), and so they are going outside more frequently in search of jobs (OR = 9.984, P < .01). Due to fear of COVID-19 infection and lack of livelihood means, respondents (76.6%) have been stressed out (overall score 3.19 ± 0.81 on a 4-point Likert-type scale), and those working in industries (OR = 5.818, P < .01), farmers (OR = 3.029, P < .05), and day laborers (OR = 2.651, P < .05) have been highly stressed.
    Matched MeSH terms: Disease Outbreaks*
  4. Fulltext A 'what-if' scenario: Nipah virus attacks pig trade chains in Thailand
    Wongnak P, Thanapongtharm W, Kusakunniran W, Karnjanapreechakorn S, Sutassananon K, Kalpravidh W, et al.
    BMC Vet Res, 2020 Aug 24;16(1):300.
    PMID: 32838786 DOI: 10.1186/s12917-020-02502-4
    BACKGROUND: Nipah virus (NiV) is a fatal zoonotic agent that was first identified amongst pig farmers in Malaysia in 1998, in an outbreak that resulted in 105 fatal human cases. That epidemic arose from a chain of infection, initiating from bats to pigs, and which then spilled over from pigs to humans. In Thailand, bat-pig-human communities can be observed across the country, particularly in the central plain. The present study therefore aimed to identify high-risk areas for potential NiV outbreaks and to model how the virus is likely to spread. Multi-criteria decision analysis (MCDA) and weighted linear combination (WLC) were employed to produce the NiV risk map. The map was then overlaid with the nationwide pig movement network to identify the index subdistricts in which NiV may emerge. Subsequently, susceptible-exposed-infectious-removed (SEIR) modeling was used to simulate NiV spread within each subdistrict, and network modeling was used to illustrate how the virus disperses across subdistricts.

    RESULTS: Based on the MCDA and pig movement data, 14 index subdistricts with a high-risk of NiV emergence were identified. We found in our infectious network modeling that the infected subdistricts clustered in, or close to the central plain, within a range of 171 km from the source subdistricts. However, the virus may travel as far as 528.5 km (R0 = 5).

    CONCLUSIONS: In conclusion, the risk of NiV dissemination through pig movement networks in Thailand is low but not negligible. The risk areas identified in our study can help the veterinary authority to allocate financial and human resources to where preventive strategies, such as pig farm regionalization, are required and to contain outbreaks in a timely fashion once they occur.

    Matched MeSH terms: Disease Outbreaks/prevention & control
  5. Zika virus in Vietnam, Laos, and Cambodia: are there health risks for travelers?
    Dinh TC, Bac ND, Minh LB, Ngoc VTN, Pham VH, Vo HL, et al.
    Eur J Clin Microbiol Infect Dis, 2019 Sep;38(9):1585-1590.
    PMID: 31044332 DOI: 10.1007/s10096-019-03563-6
    Vietnam, Laos, and Cambodia have reported first cases of Zika virus (ZIKV) infection since 2010 (Cambodia) and 2016 (Vietnam and Laos). One case of ZIKV-related microcephaly was recognized among a hundred infected cases in these areas, raising a great concern about the health risk related to this virus infection. At least 5 cases of ZIKV infection among travelers to Vietnam, Laos, and Cambodia were recorded. It is noticeable that ZIKV in these areas can cause birth defects. This work aims to discuss the current epidemics of ZIKV in Vietnam, Laos, and Cambodia and update the infection risk of ZIKV for travelers to these areas.
    Matched MeSH terms: Disease Outbreaks/statistics & numerical data
  6. Fulltext An outbreak of gastroenteritis by emerging norovirus GII.2[P16] in a kindergarten in Kota Kinabalu, Malaysian Borneo
    Ahmed K, Dony JJF, Mori D, Haw LY, Giloi N, Jeffree MS, et al.
    Sci Rep, 2020 04 28;10(1):7137.
    PMID: 32346119 DOI: 10.1038/s41598-020-64148-4
    Outbreaks of diarrhea in kindergartens are underreported and frequently go unnoticed in developing countries. To better understand the etiology this study was performed during an outbreak of diarrhea in a kindergarten in Sabah, Malaysia. Outbreak investigation was performed according to the standard procedures. In this outbreak a total of 34 (36.5%) children and 4 (30.8%) teachers suffered from gastroenteritis. Stool samples from seven children and 13 teachers were tested for rotavirus and norovirus. During the investigation stool samples were collected and sent in cold chain to the laboratory. The samples were subjected to rotavirus enzyme linked immunosorbent assay, and reverse transcription PCR for norovirus. All samples were negative for rotavirus but positive for norovirus. To determine the genogroup and genotype of norovirus, nucleotide sequencing of the amplicons was performed. All norovirus from the outbreak was of genotype GII.2[16]. To determine the relatedness of the strains phylogenetic analysis was done using neighbor-joining method. Phylogenetically these strains were highly related to GII.2[P16] noroviruses from China and Japan. This study provided evidence that a diarrheal outbreak in a kindergarten was caused by GII.2[P16] norovirus which is an emerging strain in East Asia and Europe.
    Matched MeSH terms: Disease Outbreaks*
  7. Fulltext Implementation of a COVID-19 surveillance programme for healthcare workers in a teaching hospital in an upper-middle-income country
    Wan KS, Tok PSK, Yoga Ratnam KK, Aziz N, Isahak M, Ahmad Zaki R, et al.
    PLoS One, 2021;16(4):e0249394.
    PMID: 33852588 DOI: 10.1371/journal.pone.0249394
    INTRODUCTION: The reporting of Coronavirus Disease 19 (COVID-19) mortality among healthcare workers highlights their vulnerability in managing the COVID-19 pandemic. Some low- and middle-income countries have highlighted the challenges with COVID-19 testing, such as inadequate capacity, untrained laboratory personnel, and inadequate funding. This article describes the components and implementation of a healthcare worker surveillance programme in a designated COVID-19 teaching hospital in Malaysia. In addition, the distribution and characteristics of healthcare workers placed under surveillance are described.

    MATERIAL AND METHODS: A COVID-19 healthcare worker surveillance programme was implemented in University Malaya Medical Centre. The programme involved four teams: contact tracing, risk assessment, surveillance and outbreak investigation. Daily symptom surveillance was conducted over fourteen days for healthcare workers who were assessed to have low-, moderate- and high-risk of contracting COVID-19. A cross-sectional analysis was conducted for data collected over 24 weeks, from the 6th of March 2020 to the 20th of August 2020.

    RESULTS: A total of 1,174 healthcare workers were placed under surveillance. The majority were females (71.6%), aged between 25 and 34 years old (64.7%), were nursing staff (46.9%) and had no comorbidities (88.8%). A total of 70.9% were categorised as low-risk, 25.7% were moderate-risk, and 3.4% were at high risk of contracting COVID-19. One-third (35.2%) were symptomatic, with the sore throat (23.6%), cough (19.8%) and fever (5.0%) being the most commonly reported symptoms. A total of 17 healthcare workers tested positive for COVID-19, with a prevalence of 0.3% among all the healthcare workers. Risk category and presence of symptoms were associated with a positive COVID-19 test (p<0.001). Fever (p<0.001), cough (p = 0.003), shortness of breath (p = 0.015) and sore throat (p = 0.002) were associated with case positivity.

    CONCLUSION: COVID-19 symptom surveillance and risk-based assessment have merits to be included in a healthcare worker surveillance programme to safeguard the health of the workforce.

    Matched MeSH terms: Disease Outbreaks/prevention & control*
  8. Social, behavioural and environmental factors and their impact on infectious disease outbreaks
    Heymann DL
    J Public Health Policy, 2005 Apr;26(1):133-9.
    PMID: 15906882
    The microbes that cause infectious diseases are complex, dynamic, and constantly evolving. They reproduce rapidly, mutate frequently, breach species barriers, adapt with relative ease to new hosts and new environments, and develop resistance to the drugs used to treat them. In their article "Meeting the challenge of epidemic infectious diseases outbreaks: an agenda for research", Kai-Lit Phua and Lai Kah Lee clearly demonstrate how social, behavioural and environmental factors, linked to a host of human activities, have accelerated and amplified these natural phenomena. By reviewing published and non-published information about outbreaks of Nipah virus in Malaysia, severe acute respiratory syndrome (SARS) and avian influenza in Asia, and the HIV pandemic, they provide a series of examples that demonstrate the various social, behavioural and environmental factors of these recent infectious disease outbreaks. They then analyse some of these same determinants in important historical epidemics and pandemics such as plague in medieval Europe, and conclude that it is important to better understand the social conditions that facilitate the appearance of diseases outbreaks in order to determine why and how societies react to outbreaks and their impact on different population groups.
    Matched MeSH terms: Disease Outbreaks/prevention & control*
  9. Fulltext Prediction of dengue outbreak in Selangor Malaysia using machine learning techniques
    Salim NAM, Wah YB, Reeves C, Smith M, Yaacob WFW, Mudin RN, et al.
    Sci Rep, 2021 01 13;11(1):939.
    PMID: 33441678 DOI: 10.1038/s41598-020-79193-2
    Dengue fever is a mosquito-borne disease that affects nearly 3.9 billion people globally. Dengue remains endemic in Malaysia since its outbreak in the 1980's, with its highest concentration of cases in the state of Selangor. Predictors of dengue fever outbreaks could provide timely information for health officials to implement preventative actions. In this study, five districts in Selangor, Malaysia, that demonstrated the highest incidence of dengue fever from 2013 to 2017 were evaluated for the best machine learning model to predict Dengue outbreaks. Climate variables such as temperature, wind speed, humidity and rainfall were used in each model. Based on results, the SVM (linear kernel) exhibited the best prediction performance (Accuracy = 70%, Sensitivity = 14%, Specificity = 95%, Precision = 56%). However, the sensitivity for SVM (linear) for the testing sample increased up to 63.54% compared to 14.4% for imbalanced data (original data). The week-of-the-year was the most important predictor in the SVM model. This study exemplifies that machine learning has respectable potential for the prediction of dengue outbreaks. Future research should consider boosting, or using, nature inspired algorithms to develop a dengue prediction model.
    Matched MeSH terms: Disease Outbreaks/prevention & control*
  10. Fulltext Surveillance of Aedes albopictus Skuse breeding preference in selected dengue outbreak localities, peninsular Malaysia
    Rozilawati H, Tanaselvi K, Nazni WA, Mohd Masri S, Zairi J, Adanan CR, et al.
    Trop Biomed, 2015 Mar;32(1):49-64.
    PMID: 25801254 MyJurnal
    Entomological surveillance was conducted in order to determine the abundance and to evaluate any changes of biological vectors or ecology, especially in the dengue outbreak areas. The abundance and breeding preference of Aedes albopictus and Aedes aegypti were conducted in selected dengue outbreak localities in three states of peninsular Malaysia namely Selangor, Federal Territory of Kuala Lumpur, and Penang Island using ovitraps and larval survey method. It was determined that Ae. albopictus was predominant in most of the localities and found to breed more outdoor than indoor. A wide range of breeding foci were recorded in this study. It was also determined that ovitrap method was more effective to detect the presence of Aedes mosquitoes when the larval survey was at low rate of infestation. The abundance of Ae. albopictus in dengue outbreak localities emphasis that the vector control programme should also target this species together with the primary dengue vector, Ae. aegypti.
    Matched MeSH terms: Disease Outbreaks*
  11. Fulltext Bleeding outcome during a dengue outbreak in 2005 in the East-coast region of Peninsular Malaysia: a prospective study
    Fariz-Safhan MN, Tee HP, Abu Dzarr GA, Sapari S, Lee YY
    Trop Biomed, 2014 Jun;31(2):270-80.
    PMID: 25134895 MyJurnal
    During a dengue outbreak in 2005 in the East-coast region of Peninsular Malaysia, one of the worst hit areas in the country at that time, we undertook a prospective study. We aimed to describe the bleeding outcome and changes in the liver and hematologic profiles that were associated with major bleeding outcome during the outbreak. All suspected cases of dengue admitted into the only referral hospital in the region during the outbreak were screened for WHO 2002 criteria and serology. Liver function, hematologic profile and severity of bleeding outcome were carefully documented. The association between symptoms, liver and hematologic impairments with the type of dengue infection (classical vs. hemorrhagic) and bleeding outcome (major vs. non-major) was tested. Dengue fever was confirmed in 183 cases (12.5/100,000 population) and 144 cases were analysed. 59.7% were dengue hemorrhagic fever, 3.5% were dengue shock syndrome and there were 3 in-hospital deaths. Major bleeding outcome (gastrointestinal bleeding, intracranial bleeding or haemoptysis) was present in 14.6%. Elevated AST, ALT and bilirubin were associated with increasing severity of bleeding outcome (all P < 0.05). Platelet count and albumin level were inversely associated with increasing severity of bleeding outcome (both P < 0.001). With multivariable analysis, dengue hemorrhagic fever was more likely in the presence of abdominal pain (OR 1.1, 95% CI 0.02- 1.6) and elevated AST (OR 1.0, 95% CI 1.0-1.1) but the presence of pleural effusion (OR 5.8, 95% CI: 1.1-29.9) and elevated AST (OR 1.008, 95% CI: 1.005-1.01) predicted a severe bleeding outcome. As a conclusion, the common presence of a severe hemorrhagic form of dengue fever may explain the rising death toll in recent outbreaks and the worst impairment in liver and hematologic profiles was seen in major bleeding outcome.
    Study site: Hospital Tengku Ampuan Afzan (HTAA), Kuantan, Pahang, Malaysia
    Matched MeSH terms: Disease Outbreaks*
  12. Fulltext Aedes larval population dynamics and risk for dengue epidemics in Malaysia
    Rohani A, Suzilah I, Malinda M, Anuar I, Mohd Mazlan I, Salmah Maszaitun M, et al.
    Trop Biomed, 2011 Aug;28(2):237-48.
    PMID: 22041742
    Early detection of a dengue outbreak is an important first step towards implementing effective dengue interventions resulting in reduced mortality and morbidity. A dengue mathematical model would be useful for the prediction of an outbreak and evaluation of control measures. However, such a model must be carefully parameterized and validated with epidemiological, ecological and entomological data. A field study was conducted to collect and analyse various parameters to model dengue transmission and outbreak. Dengue prone areas in Kuala Lumpur, Pahang, Kedah and Johor were chosen for this study. Ovitraps were placed outdoor and used to determine the effects of meteorological parameters on vector breeding. Vector population in each area was monitored weekly for 87 weeks. Weather stations, consisting of a temperature and relative humidity data logger and an automated rain gauge, were installed at key locations in each study site. Correlation and Autoregressive Distributed Lag (ADL) model were used to study the relationship among the variables. Previous week rainfall plays a significant role in increasing the mosquito population, followed by maximum humidity and temperature. The secondary data of rainfall, temperature and humidity provided by the meteorological department showed an insignificant relationship with the mosquito population compared to the primary data recorded by the researchers. A well fit model was obtained for each locality to be used as a predictive model to foretell possible outbreak.
    Matched MeSH terms: Disease Outbreaks*
  13. Fulltext Entire genome characterization of Chikungunya virus from the 2008-2009 outbreaks in Thailand
    Pongsiri P, Auksornkitti V, Theamboonlers A, Luplertlop N, Rianthavorn P, Poovorawan Y
    Trop Biomed, 2010 Aug;27(2):167-76.
    PMID: 20962712 MyJurnal
    The resurgence of Chikungunya virus (CHIKV) in the southern, northeastern and northern parts of Thailand, inflicting approximately 46,000 reported cases since October 2008 until December 2009, has raised public health concerns. In the present study, we characterized nearly complete genome sequences of four CHIKV isolates obtained from 2008 to 2009 outbreaks in Thailand. Phylogenetic analysis was performed to determine the relationships of the study viruses with previously reported isolates. Results showed that 2008-2009 Thailand isolates belonged to the East, Central and South African genotype and were most closely related to isolates detected in Malaysia and Singapore in 2008. This was in contrast to isolates from all previous outbreaks in Thailand which were caused by an Asian genotype. We describe several novel mutations in Thailand isolates that warrants further investigation on characterization of CHIKV from different parts of the country to better understand the molecular epidemiology of Chikungunya fever outbreaks in Thailand.
    Matched MeSH terms: Disease Outbreaks*
  14. Fulltext First report of bovine lungworm disease in South-East Asia
    Lat-Lat H, Hassan L, Sani RA, Sheikh-Omar AR, Hishamfariz M, Ng V
    Trop Biomed, 2007 Jun;24(1):77-81.
    PMID: 17568380 MyJurnal
    This paper presents investigation of lungworm disease outbreaks that is based on retrospective examination of cases recorded between 1994 and 2000 on a government beef cattle breeding centre in the state of Pahang, peninsular Malaysia. The breed of cattle on the centre was Nelore and the mean population over a 7-year period (from 1994 to 2000) was 1612. All animals were allowed to graze on pasture and mixed grazing was practiced on the farm. The routine de-worming programme was performed using levamisole and ivermectin from 1994 to 1998 and abamectin in 1999 and 2000 on 1 to 3-month-old calves and an annual dose given to the adult cattle. Nelore was introduced into the farm in 1991, three years before the first outbreak from Brazil where Dictyocaulus viviparus infection had been reported. No lungworm infection had been observed in the farm prior to the animal introduction. Within the 7-year period, 36 fatalities occurred and the annual mortality rate due to lungworm infection was 0.31%. The highest rate was recorded in 1997. Among the total 36 deaths, about 75% of deaths occurred in calves aged between 6 months and 12 months, 67% were males and 33% were female cattle. The highest number of deaths (19%) occurred in the month of November. In conclusion, D. viviparus infection may have been introduced into a tropical climate along with consignments of cattle from lungworm endemic areas resulting in fatal disease outbreaks for a few years following the animal's initial introduction.
    Matched MeSH terms: Disease Outbreaks/veterinary
  15. Fulltext Spatial, environmental and entomological risk factors analysis on a rural dengue outbreak in Lundu District in Sarawak, Malaysia
    Cheah WL, Chang MS, Wang YC
    Trop Biomed, 2006 Jun;23(1):85-96.
    PMID: 17041556 MyJurnal
    The objective of this study was to elucidate the association of various risk factors with dengue cases reported in Lundu district, Sarawak, by analyzing the interaction between environmental, entomological, socio-demographic factors. Besides conventional entomological, serological and house surveys, this study also used GIS technology to generate geographic and environmental data on Aedes albopictus and dengue transmission. Seven villages were chosen based on the high number of dengue cases reported. A total of 551 households were surveyed. An overall description of the socio-demographic background and basic facilities was presented together with entomological and geographical profiles. For serological and ovitrap studies, systematic random sampling was used. Serological tests indicated that 23.7% of the 215 samples had a history of dengue, either recent or previous infections. Two samples (0.9%) were confirmed by IgM ELISA and 49 samples (22.8%) had IgG responses. A total of 32,838 Aedes albopictus eggs were collected in 56 days of trapping. Cluster sampling was also done to determine whether any of the risk factors (entomological or geographical) were influenced by geographical location. These clusters were defined as border villages with East Kalimantan and roadside villages along Lundu/Biawas trunk road. The data collected were analyzed using SPSS version 10.01. Descriptive analysis using frequency, means, and median were used. To determine the association between variables and dengue cases reported, and to describe the differences between the two clusters of villages, two-sample t-test, and Pearson's Chi-Square were used. Accurate maps were produced with overlay and density function, which facilitates the map visualization and report generating phases. This study also highlights the use of differential Global Positioning System in mapping sites of 1m accuracy. Analysis of the data revealed there are significant differences in clusters of villages attributable to container density, house density, distance of the house from the main road, and number of Ae. albopictus eggs from ovitraps set indoor, outdoor and in dumping sites (Person's Chi-Square = 6.111, df = 1, p < 0.01). Further analysis using t-test showed that house density, container density, indoor mosquitoes egg count, outdoor mosquitoes egg count, and dumping sites mosquitoes egg count were higher at the roadside villages compared to border villages. A number of potential risk factors including those generated from GIS were investigated. None of the factors investigated in this study were associated with the dengue cases reported.
    Matched MeSH terms: Disease Outbreaks*
  16. Zika virus infection and Guillain-Barré syndrome: a review focused on clinical and electrophysiological subtypes
    Uncini A, Shahrizaila N, Kuwabara S
    J Neurol Neurosurg Psychiatry, 2017 03;88(3):266-271.
    PMID: 27799296 DOI: 10.1136/jnnp-2016-314310
    In 2016, we have seen a rapid emergence of Zika virus-associated Guillain-Barré syndrome (GBS) since its first description in a French-Polynesian patient in 2014. Current evidence estimates the incidence of GBS at 24 cases per 100 000 persons infected by Zika virus. This will result in a sharp rise in the number of GBS cases worldwide with the anticipated global spread of Zika virus. A better understanding of the pathogenesis of Zika-associated GBS is crucial to prepare us for the current epidemic. In this review, we evaluate the existing literature on GBS in association with Zika and other flavivirus to better define its clinical subtypes and electrophysiological characteristics, demonstrating a demyelinating subtype of GBS in most cases. We also recommend measures that will help reduce the gaps in knowledge that currently exist.
    Matched MeSH terms: Disease Outbreaks*
  17. Outbreak of A2-Hong Kong-68 influenza at an international medical conference
    Saenz AC, Assaad FA, Cockburn WC
    Lancet, 1969 Jan 11;1(7585):91-3.
    PMID: 4178014
    Matched MeSH terms: Disease Outbreaks*
  18. A shellfish-borne cholera outbreak in Malaysia
    Dutt AK, Alwi S, Velauthan T
    Trans R Soc Trop Med Hyg, 1971;65(6):815-8.
    PMID: 5157442
    Matched MeSH terms: Disease Outbreaks*
  19. Epidemic hysteria in Malaysian schools: an illustrative episode
    Teoh JI, Soewondo S, Sidharta M
    Psychiatry, 1975 Aug;38(3):258-68.
    PMID: 1197502
    This paper discusses the prevalence and characteristics of epidemic hysteria among predominantly rural Malay schools in Malaysia. An illustrative episode in a Malay residential girls' school is described, and contributory factors to this outbreak are elaborated. An attempt is made to analyze the complex interweaving of psychological, religious, cultural, and sociological factors in the precipitation of the outbreak.
    Matched MeSH terms: Disease Outbreaks*
  20. Disruption of predicted dengue virus type 3 major outbreak cycle coincided with switching of the dominant circulating virus genotype
    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: Disease Outbreaks*
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