Current perspectives on dengue episode in Malaysia

Effectiveness of the Integrated Dengue Education and Learning (iDEAL) module in improving the knowledge, attitude, practice, environmental cleanliness index, and dengue index among schoolchildren: A randomised controlled trial protocol

BACKGROUND

Dengue is a mosquito-borne disease caused by four distinct, closely related dengue viruses (DENV). Global dengue incidence has markedly increased in the past decades. The World Health Organization reported that cases increased from 505,430 in 2000 to 5.2 million in 2019. Similarly, the total dengue cases in Malaysia increased from 7,103 in 2000 to a peak of 130,101 in 2019. Knowledge, attitude, and practice (KAP) remain the most effective dengue prevention and control tools. Furthermore, school-based health education is key to enhancing knowledge and raising awareness of the seriousness of dengue among schoolchildren and transferring knowledge and practice from classrooms to homes. Thus, it is necessary to plan an integrated module for the primary prevention of dengue infection, specifically among schoolchildren.

AIMS

The present study intends to develop, implement, and evaluate the effectiveness of a theory-based integrated dengue education and learning (iDEAL) module in improving the KAP, environmental cleanliness index, and dengue index among schoolchildren in Selangor and Kuala Lumpur.

METHODS

This study is a single-blinded, cluster randomised controlled trial to be conducted from 1 September 2023 to 31 August 2025. The study will involve 20 primary and 20 secondary schools in Selangor and Kuala Lumpur. The 1600 participants will be randomly allocated to intervention and control groups based on selected clusters to avoid contamination. A cluster is a comparable school that fulfils the inclusion and exclusion criteria. The intervention group will receive the iDEAL module, while the control group will receive standard education. The iDEAL module will be developed following a systematic procedure and delivered in-person by trained researchers to the participants. The outcome will be measured using validated, self-administered questionnaires at baseline (T0), immediately (T1), one month (T2), and three months (T3) post-intervention to measure the intervention module effectiveness. The data will be analysed using IBM Statistical Package for Social Science (SPSS) version 28 and descriptive and inferential statistics. Within-group changes over time will be compared using one-way repeated measure analysis of variance for continuous and normally distributed variables. Within-group analysis of categorical data will use Cochran's Q test. The main effect and interaction between and within the intervention and control groups at T0, T1, T2, and T3 will be tested using the generalised linear mixed model (GLMM). Hypothetically, the KAP, environmental cleanliness index, and dengue index among the intervention group will be significantly improved compared to the control group. The hypothesis will be tested using a significance level with a p-value of 0.05 and a confidence interval of 95%.

CONCLUSIONS

The study protocol outlines developing and testing an iDEAL module for schoolchildren in Selangor and Kuala Lumpur, with no socio-demographic differences expected. The intervention aims to improve KAP, environmental cleanliness index, and dengue index, potentially reducing dengue risk. Results could inform public health policies, emphasizing school-based interventions' importance in combating diseases like dengue.

Rickettsial Infections Are Neglected Causes of Acute Febrile Illness in Teluk Intan, Peninsular Malaysia

Rickettsial infections are among the leading etiologies of acute febrile illness in Southeast Asia. However, recent data from Malaysia are limited. This prospective study was conducted in Teluk Intan, Peninsular Malaysia, during January to December 2016. We recruited 309 hospitalized adult patients with acute febrile illness. Clinical and biochemistry data were obtained, and patients were stratified into mild and severe infections based on the sepsis-related organ failure (qSOFA) scoring system. Diagnostic assays including blood cultures, real-time PCR, and serology (IFA and MAT) were performed. In this study, pathogens were identified in 214 (69%) patients, of which 199 (93%) patients had a single etiology, and 15 (5%) patients had >1 etiologies. The top three causes of febrile illness requiring hospitalization in this Malaysian study were leptospirosis (68 (32%)), dengue (58 (27%)), and rickettsioses (42 (19%)). Fifty-five (18%) patients presented with severe disease with a qSOFA score of ≥2. Mortality was documented in 38 (12%) patients, with the highest seen in leptospirosis (16 (42%)) followed by rickettsiosis (4 (11%)). While the significance of leptospirosis and dengue are recognized, the impact of rickettsial infections in Peninsular Malaysia remains under appreciated. Management guidelines for in-patient care with acute febrile illness in Peninsular Malaysia are needed.

The knowledge, attitude and practice of community people on dengue fever in Central Nepal: a cross-sectional study

Background

Since 2006, Nepal has experienced frequent Dengue fever (DF) outbreaks. Up to now, there have been no knowledge, attitude and practice (KAP) studies carried out on DF in Nepal that have included qualitative in-depth and quantitative data. Thus, we aimed to explore and compare the KAP of people residing in the lowland (< 1500 m) and highland (> 1500 m) areas of Nepal.

Methods

A cross-sectional mixed-method study was conducted in six districts of central Nepal in September–October 2018 including both quantitative (660 household surveys) and qualitative data (12 focus group discussions and 27 in-depth interviews). The KAP assessment was executed using a scoring system and defined as high or low based on 80% cut-off point. Logistic regression was used to investigate the associated factors, in quantitative analysis. The deductive followed by inductive approach was adopted to identify the themes in the qualitative data.

Results

The study revealed that both the awareness about DF and prevention measures were low. Among the surveyed participants, 40.6% had previously heard about DF with a significantly higher number in the lowland areas. Similarly, IDI and FGD participants from the lowland areas were aware about DF, and it’s associated symptoms, hence they were adopting better preventive practices against DF. The findings of both the qualitative and quantitative data indicate that people residing in the lowland areas had better knowledge on DF compared to people in highland areas. All IDI participants perceived a higher chance of increasing future dengue outbreaks due to increasing temperature and the mobility of infected people from endemic to non-endemic areas. The most quoted sources of information were the television (71.8%) and radio (51.5%). Overall, only 2.3% of the HHS participants obtained high knowledge scores, 74.1% obtained high attitude scores and 21.2% obtained high preventive practice scores on DF. Among the socio-demographic variables, the area of residence, educational level, age, monthly income, SES and occupation were independent predictors of knowledge level, while the education level of the participants was an independent predictor of the attitude level.

Conclusions

Our study found a very low level of knowledge and insufficient preventive practices. This highlights an urgent need for extensive dengue prevention programs in both highland and lowland communities of Nepal.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07404-4.

Statewide Efficacy Assessment of Insect Growth Regulators Against Aedes albopictus (Diptera: Culicidae) in Sabah, Malaysia: An Alternative Control Strategy?

The efficacy of three groups of insect growth regulators, namely juvenile hormone mimics (methoprene and pyriproxyfen), chitin synthesis inhibitors (diflubenzuron and novaluron), and molting disruptor (cyromazine) was evaluated for the first time, against Aedes albopictus Skuse (Diptera: Culicidae) larvae from 14 districts in Sabah, Malaysia. The results showed that all field populations of Ae. albopictus were susceptible towards methoprene, pyriproxyfen, diflubenzuron, novaluron, and cyromazine, with resistance ratio values ranging from 0.50-0.90, 0.60-1.00, 0.67-1.17, 0.71-1.29, and 0.74-1.07, respectively. Overall, the efficacy assessment of insect growth regulators in this study showed promising outcomes and they could be further explored as an alternative to conventional insecticides.

Usage of Traditional and Complementary Medicine among Dengue Fever Patients in the Northeast Region of Peninsular Malaysia

Background

The recent epidemic of dengue fever (DF) in Malaysia was alarming. The treatment of DF remains supportive as there is no anti-viral agent or vaccine available as yet. Traditional and complementary medicine (T&CM) provides an alternative option for the treatment of DF but there is limited evidence with regard to its usage. The aim of this study was to determine the prevalence, types and predictor factors of T&CM usage among DF patients in the northeast region of Peninsular Malaysia.

Methodology

This was a cross-sectional study of DF patients in the northeast region of Peninsular Malaysia who had been admitted to a tertiary centre from January 2014 until December 2015. Serologically-confirmed DF patients aged 18 years and above were randomly selected. Phone interviews were conducted to obtain information regarding the use of T&CM during hospitalisation. Notes were made regarding the prevalence and type of T&CM used. Binary logistic regressions were used to identify the predictor factors of T&CM usage.

Results

A total of 241 DF patients with a mean age of 36.62 (SD = 14.62) years were included. The estimated prevalence of T&CM usage was 84.6% (95%CI: 80.1%, 89.2%). The most common T&CM used were crab soup (85.3%), papaya leaf extract (64.2%) and isotonic drinks (61.8%). The significant predictors for T&CM usage were age [adjusted odds ratio (AOR) 0.97; 95%CI: 0.94, 0.99], tertiary education (AOR 3.86; 95%CI: 1.21, 12.32) and unemployment (AOR 2.55; 95%CI: 1.02, 6.42).

Conclusion

The prevalence of T&CM usage in our population is high. Age, tertiary education and unemployment influence the use of T&CM.

Mast cell stabilizing effect of a geranyl acetophenone in dengue virus infection using in vitro model of DENV3-induced RBL-2H3 cells

Mast cells (MCs), a type of immune effector cell, have recently become recognized for their ability to cause vascular leakage during dengue virus (DENV) infection. Although MC stabilizers have been reported to attenuate DENV induced infection in animal studies, there are limited in vitro studies on the use of MC stabilizers against DENV induced MC degranulation. 2,4,6-trihydroxy-3-geranyl acetophenone (tHGA) has been reported to be a potential MC stabilizer by inhibiting IgE-mediated MC activation in both cellular and animal models. The present study aims to establish an in vitro model of DENV3-induced RBL-2H3 cells using ketotifen fumarate as a control drug, as well as to determine the effect of tHGA on the release of MC mediators upon DENV infection. Our results demonstrated that the optimal multiplicities of infection (MOI) were 0.4 × 10^-2 and 0.8 × 10^-2 focus forming units (FFU)/cell. Ketotifen fumarate was proven to attenuate DENV3-induced RBL-2H3 cells degranulation in this in vitro model. In contrast, tHGA was unable to attenuate the release of both β-hexosaminidase and tumor necrosis factor (TNF)-α. Nonetheless, our study has successfully established an in vitro model of DENV3-induced RBL-2H3 cells, which might be useful for the screening of potential MC stabilizers for anti-dengue therapies.

Epitope Presentation of Dengue Viral Envelope Glycoprotein Domain III on Hepatitis B Core Protein Virus-Like Particles Produced in Nicotiana benthamiana

Dengue fever is currently ranked as the top emerging tropical disease, driven by increased global travel, urbanization, and poor hygiene conditions as well as global warming effects which facilitate the spread of Aedes mosquitoes beyond their current distribution. Today, more than 100 countries are affected most of which are tropical Asian and Latin American nations with limited access to medical care. Hence, the development of a dengue vaccine that is dually cost-effective and able to confer a comprehensive protection is ultimately needed. In this study, a consensus sequence of the antigenic dengue viral glycoprotein domain III (cEDIII) was used aiming to provide comprehensive coverage against all four circulating dengue viral serotypes and potential clade replacement event. Utilizing hepatitis B tandem core technology, the cEDIII sequence was inserted into the immunodominant c/e1 loop region so that it could be displayed on the spike structures of assembled particles. The tandem core particles displaying cEDIII epitopes (tHBcAg-cEDIII) were successfully produced in Nicotiana benthamiana via Agrobacterium-mediated transient expression strategy to give a protein of ∼54 kDa, detected in both soluble and insoluble fractions of plant extracts. The assembled tHBcAg-cEDIII virus-like particles (VLPs) were also visualized from transmission electron microscopy. These VLPs had diameters that range from 32 to 35 nm, presenting an apparent size increment as compared to tHBcAg control particles without cEDIII display (namely tEL). Mice immunized with tHBcAg-cEDIII VLPs showed a positive seroconversion to cEDIII antigen, thereby signifying that the assembled tHBcAg-cEDIII VLPs have successfully displayed cEDIII antigen to the immune system. If it is proven to be successful, tHBcAg-cEDIII has the potential to be developed as a cost-effective vaccine candidate that confers a simultaneous protection against all four infecting dengue viral serotypes.

Using clinical practice guidelines to manage dengue: a qualitative study in a Malaysian hospital

Background

Malaysia has rising dengue incidence. World Health Organization clinical practice guidelines for managing dengue have been adapted by the Ministry of Health in Malaysia, with evidence of good awareness by clinicians. However, dengue mortality has not reduced. This study aimed to explore the challenges of dengue management for Medical Officers, with a particular focus on use of clinical practice guidelines.

Methods

Qualitative study using six focus groups and 14 semi-structured interviews with doctors responsible for dengue management at a large tertiary hospital in Malaysia.

Results

Dengue was recognised as difficult to diagnose and manage. Wide awareness and use of both WHO and Ministry of Health guidelines was reported, but several limitations noted in their coverage of particular patient groups. However, the phrase ‘guidelines’ also referred to local algorithms for fluid management, which were less clinically evidence-based. Where Medical Officers were well trained in the appropriate use of evidence-based guidelines, barriers to use included: the potential for ‘following the algorithm’ to undermine junior clinicians’ claims to clinical expertise; inability to recognise the pattern of clinical progress; and lack of clinical experience. Other reported barriers to improved case management were resource constraints, poor referral practices, and insufficient awareness of the need for timely help seeking.

Conclusions

Awareness of clinical practice guidelines is a necessary, but not sufficient, condition for optimal dengue management. In high prevalence settings, all clinical staff would benefit from regular dengue management training which should include diagnosis, practice in monitoring disease progression and the use of clinical practice guidelines in a range of clinical contexts.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3680-5) contains supplementary material, which is available to authorized users.

The distribution of important sero-complexes of flaviviruses in Malaysia

Flaviviruses (FVs) are arthropod-borne viruses of medical and veterinary importance. Numerous species of FVs have been isolated from various host; mainly humans, animals, ticks, and mosquitoes. Certain FVs are extremely host-specific; at the same time, some FVs can infect an extensive range of species. Based on published literatures, 11 species of FVs have been detected from diverse host species in Malaysia. In humans, dengue virus and Japanese encephalitis virus have been reported since 1901 and 1942. In animals, the Batu Cave virus, Sitiawan virus, Carey Island, Tembusu virus, Duck Tembusu virus, and Japanese encephalitis viruses were isolated from various species. In mosquitoes, Japanese encephalitis virus and Kunjin virus were isolated from Culex spp., while Zika virus and Jugra virus were isolated from Aedes spp. In ticks, the Langat virus was isolated from Ixodes spp. One of the major challenges in the diagnosis of FVs is the presence of sero-complexes as a result of cross-reactivity with one or more FV species. Subsequently, the distribution of specific FVs among humans and animals in a specific population is problematic to assess and often require comprehensive and thorough analyses. Molecular assays such as quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and digital droplet RT-PCR (ddRT-PCR) have been used for the differentiation of flavivirus infections to increase the accuracy of epidemiological data for disease surveillance, monitoring, and control. In situations where sero-complexes are common in FVs, even sensitive assays such as qRT-pCR can produce false positive results. In this write up, an overview of the various FV sero-complexes reported in Malaysia to date and the challenges faced in diagnosis of FV infections are presented.