Background:Globally,dengue infections constitute a significant public health burden.In recent decades,Malaysia has become a dengue hyper-endemic country with the co-circulation of the four dengue virus serotypes.The c...Background:Globally,dengue infections constitute a significant public health burden.In recent decades,Malaysia has become a dengue hyper-endemic country with the co-circulation of the four dengue virus serotypes.The cyclical dominance of sub-types contributes to a pattern of major outbreaks.The consequences can be observed in the rising incidence of reported dengue cases and dengue related deaths.Understanding the complex interaction of the dengue virus,its human hosts and the mosquito vectors at the community level may help develop strategies for addressing the problem.Methods:A prospective cohort study will be conducted in Segamat district of Johor State in Peninsular Malaysia.Researchers received approval from the Malaysian Medical Research Ethics Committee and Monash University Human Research Ethics Committee.The study will be conducted at a Malaysian based health and demographic surveillance site over a 1 year period in three different settings(urban,semi-urban and rural).The study will recruit healthy adults(male and female)aged 18 years and over,from three ethnic groups(Malay,Chinese and Indian).The sample size calculated using the Fleiss method with continuity correction is 333.Sero-surveillance of participants will be undertaken to identify asymptomatic,otherwise healthy cases;cases with dengue fever who are managed as out-patients;and cases with dengue fever admitted to a hospital.A genetic analysis of the participants will be undertaken to determine whether there is a relationship between genetic predisposition and disease severity.A detailed medical history,past history of dengue infection,vaccination history against other flaviviruses such as Japanese encephalitis and Yellow fever,and the family history of dengue infection will also be collected.In addition,a mosquito surveillance will be carried out simultaneously in recruitment areas to determine the molecular taxonomy of circulating vectors.Discussion:The research findings will estimate the burden of asymptomatic and symptomatic dengue at the community level.It will also examine the relationship between virus serotypes and host genotypes,and the association of the clinical manifestation of the early phase with the entire course of illness.展开更多
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,informati...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 communitybased 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 IgGpositive 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<0.001).No associations with occupation,study site,housing type,comorbidity,educational level,and marital status were observed,although the latter two were statistically significant in the univariate analysis.None of the studied factors were significantly associated with recent DENV infections in the multivariate analysis,although there was a pattern suggestive of recent outbreak in two study sites populated predominately by Chinese people.The majority of infections did not give rise to recognizable disease(either asymptomatic or nonspecific symptoms)as only 12.9%of participants(31/240)recalled having dengue in the past.Conclusions:The predominantly rural community under study had a very high previous exposure to dengue.The finding of a high proportion of unreported cases possibly due to subclinical infections underscores the need for enhanced surveillance and control methods.This finding also has implications for measuring disease burden,understanding transmission dynamics,and hypothesizing effects on DENV vaccine efficacy and uptake.展开更多
The Infectious Diseases of Poverty journal,launched a year ago,is a platform to engage outside the traditional disciplinary boundaries,and disseminate high quality science towards the improvement of health.This paper ...The Infectious Diseases of Poverty journal,launched a year ago,is a platform to engage outside the traditional disciplinary boundaries,and disseminate high quality science towards the improvement of health.This paper reviews the milestone achievements during its first year of operation.The journal has filled an important niche,addressing some of the main priorities in the Global Report for Research on Infectious Diseases of Poverty.Highlights include the publication of three thematic issues on health systems,surveillance and response systems,as well as co-infection and syndemics.The thematic issues have foregrounded the importance and innovation that can be achieved through transdisciplinary research.The journal has been indexed by PubMed since April 2013,with the publication of a total of 38 articles.Finally,the journal is delivering to wider range readers both in developing and developed countries with sustained efforts with a focus on relevant and strategic information towards elimination of infectious diseases of poverty.展开更多
基金The study is funded primarily by the“Infection and Immunity Cluster”of the“Tropical Medicine and Biology Platform”of Monash University Malaysia(fund code is 5140762)and by SEACO(fund code is 2500047)SEACO is funded by the office of the Vice Provost Research,Monash University Australia+1 种基金the office of the Deputy Dean Research,Faculty of Medicine,Nursing and Health Sciences,Monash University Australiathe Monash Malaysia School of Medicine and Health Sciences and the Monash University Malaysia Campus.
文摘Background:Globally,dengue infections constitute a significant public health burden.In recent decades,Malaysia has become a dengue hyper-endemic country with the co-circulation of the four dengue virus serotypes.The cyclical dominance of sub-types contributes to a pattern of major outbreaks.The consequences can be observed in the rising incidence of reported dengue cases and dengue related deaths.Understanding the complex interaction of the dengue virus,its human hosts and the mosquito vectors at the community level may help develop strategies for addressing the problem.Methods:A prospective cohort study will be conducted in Segamat district of Johor State in Peninsular Malaysia.Researchers received approval from the Malaysian Medical Research Ethics Committee and Monash University Human Research Ethics Committee.The study will be conducted at a Malaysian based health and demographic surveillance site over a 1 year period in three different settings(urban,semi-urban and rural).The study will recruit healthy adults(male and female)aged 18 years and over,from three ethnic groups(Malay,Chinese and Indian).The sample size calculated using the Fleiss method with continuity correction is 333.Sero-surveillance of participants will be undertaken to identify asymptomatic,otherwise healthy cases;cases with dengue fever who are managed as out-patients;and cases with dengue fever admitted to a hospital.A genetic analysis of the participants will be undertaken to determine whether there is a relationship between genetic predisposition and disease severity.A detailed medical history,past history of dengue infection,vaccination history against other flaviviruses such as Japanese encephalitis and Yellow fever,and the family history of dengue infection will also be collected.In addition,a mosquito surveillance will be carried out simultaneously in recruitment areas to determine the molecular taxonomy of circulating vectors.Discussion:The research findings will estimate the burden of asymptomatic and symptomatic dengue at the community level.It will also examine the relationship between virus serotypes and host genotypes,and the association of the clinical manifestation of the early phase with the entire course of illness.
基金Ethical approval for the study was obtained from the Medical Research Ethics Committee,Ministry of Health Malaysia(NMRR-14-42-19126)the Monash University Human Research Ethics Committee(CF14/2543–2014001379).
文摘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 communitybased 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 IgGpositive 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<0.001).No associations with occupation,study site,housing type,comorbidity,educational level,and marital status were observed,although the latter two were statistically significant in the univariate analysis.None of the studied factors were significantly associated with recent DENV infections in the multivariate analysis,although there was a pattern suggestive of recent outbreak in two study sites populated predominately by Chinese people.The majority of infections did not give rise to recognizable disease(either asymptomatic or nonspecific symptoms)as only 12.9%of participants(31/240)recalled having dengue in the past.Conclusions:The predominantly rural community under study had a very high previous exposure to dengue.The finding of a high proportion of unreported cases possibly due to subclinical infections underscores the need for enhanced surveillance and control methods.This finding also has implications for measuring disease burden,understanding transmission dynamics,and hypothesizing effects on DENV vaccine efficacy and uptake.
文摘The Infectious Diseases of Poverty journal,launched a year ago,is a platform to engage outside the traditional disciplinary boundaries,and disseminate high quality science towards the improvement of health.This paper reviews the milestone achievements during its first year of operation.The journal has filled an important niche,addressing some of the main priorities in the Global Report for Research on Infectious Diseases of Poverty.Highlights include the publication of three thematic issues on health systems,surveillance and response systems,as well as co-infection and syndemics.The thematic issues have foregrounded the importance and innovation that can be achieved through transdisciplinary research.The journal has been indexed by PubMed since April 2013,with the publication of a total of 38 articles.Finally,the journal is delivering to wider range readers both in developing and developed countries with sustained efforts with a focus on relevant and strategic information towards elimination of infectious diseases of poverty.
