The east coast districts are the possible epicenter of severe dengue in Sabah

Clinical profiles and predictors of survival in severe dengue cases

Introduction

Dengue is endemic in tropical countries. Severe dengue has a high risk of morbidity and mortality. We aimed to identify factors associated with dengue survival among our intensive care unit (ICU) patients.

Methods

A retrospective study was conducted among dengue cases admitted to the ICU of Hospital Sultan Abdul Halim, Kedah, Malaysia from 2016 to 2019.

Results

Out of 1,852 dengue cases admitted to the hospital, 7.2% of patients required ICU admission. Survival rate was 88.6% among severe dengue cases. The majority of severe dengue patients were obese, while other notable comorbidities included hypertension and diabetes mellitus. Also, 73% of patients presented in the critical phase, at a median of Day 4 of illness. All patients admitted to the ICU had a history of fever. The predominant warning signs were lethargy, fluid accumulation and haemoconcentration with rapid platelet reduction. Among nonsurvivors, 69.2% had fulminant hepatitis, 53.8% had massive bleeding or disseminated intravascular coagulation, 38.5% had haemophagocytic lymphohistiocytosis and 30.8% had myocarditis. The predominant serotypes were DENV-3 and DENV-1. The least number of cases was seen in 2017, when all serotypes were equally presented. Multiple logistic regression showed that Sequential Organ Failure Assessment (SOFA) score, peak international normalised ratio, peak partial thromboplastin time and aspartate aminotransferase on admission were independent risk factors for survival. This model had an area under the curve of 0.98, giving an overall 98.2% accuracy.

Conclusions

Specific warning signs and blood investigations in dengue patients may aid in early decision for ICU admission. Monitoring of SOFA scores plus coagulation and liver enzyme profiles could improve dengue survival rates.

The Cytokines CXCL10 and CCL2 and the Kynurenine Metabolite Anthranilic Acid Accurately Predict Patients at Risk of Developing Dengue With Warning Signs

BACKGROUND

The resolution or aggravation of dengue infection depends on the patient's immune response during the critical phase. Cytokines released by immune cells increase with the worsening severity of dengue infections. Cytokines activate the kynurenine pathway (KP) and the extent of KP activation then influences disease severity.

METHODS

KP metabolites and cytokines in plasma samples of patients with dengue infection (dengue without warning signs [DWS-], dengue with warning signs [DWS+], or severe dengue) were analyzed. Cytokines (interferon gamma [IFN-ɣ], tumor necrosis factor, interleukin 6, CXCL10/interferon-inducile protein 10 [IP-10], interleukin 18 [IL-18], CCL2/monocyte chemoattractant protein-1 [MCP-1], and CCL4/macrophage inflammatory protein-1beta [MIP-1β] were assessed by a Human Luminex Screening Assay, while KP metabolites (tryptophan, kynurenine, anthranilic acid [AA], picolinic acid, and quinolinic acid) were assessed by ultra-high-performance liquid chromatography and Gas Chromatography Mass Spectrophotometry [GCMS] assays.

RESULTS

Patients with DWS+ had increased activation of the KP where kynurenine-tryptophan ratio, anthranilic acid, and picolinic acid were elevated. These patients also had higher levels of the cytokines IFN-ɣ, CXCL10, CCL4, and IL-18 than those with DWS-. Further receiver operating characteristic analysis identified 3 prognostic biomarker candidates, CXCL10, CCL2, and AA, which predicted patients with higher risks of developing DWS+ with an accuracy of 97%.

CONCLUSIONS

The data suggest a unique biochemical signature in patients with DWS+. CXCL10 and CCL2 together with AA are potential prognostic biomarkers that discern patients with higher risk of developing DWS+ at earlier stages of infection.

Wolbachia in Dengue Control: A Systematic Review

BACKGROUND: Dengue fever outbreaks have been an important public health issue causing high morbidity and mortality, and serious economic effects, particularly in Asia. Control strategies are a challenge to be implemented due to a variety of factors. However, new approaches such as Wolbachia-infected Aedes aegypti have been shown to successfully lowering the life spans of the mosquito, eggs resistance, and disease transmission capabilities. Field trials are still on-going, and there are data to support its benefit in a large population. This systematic review aims to determine the current progress and impact of using Wolbachia in curbing dengue cases in high dengue case locations worldwide. METHODOLOGY: The study uses the Preferred Reporting Items for Systematic reviews and Meta-Analyses review protocol, while the formulation of the research question was based on population of interest, comparison, and outcome. The selected databases include Web of Science, Scopus, PubMed, SAGE, and EBSCOhost. A thorough identification, screening, and included process were done and the results retrieved four articles. These articles were then ranked based on quality using mixed methods appraisal tool. RESULTS: A total of four articles were included from 2019 and 2020 reports in both dengue- and non-dengue-endemic settings. In this review, comparisons in terms of the hierarchy of the study design, community engagement and acceptance, Wolbachia-infected A. aegypti deployment, entomological outcome, and epidemiological outcomes were detailed. All four studies showed a decrease in dengue incidence in Wolbachia-intervention populations. CONCLUSION: Wolbachia programs have been shown to be an effective method in combating dengue diseases. Strong community engagement and involvement from multidisciplinary teams are important factors to ensure the effectiveness and good outcomes of the program.

A five-year retrospective study on the epidemiology of hand, foot and mouth disease in Sabah, Malaysia

Hand, foot, and mouth disease (HFMD) is endemic in Malaysia, with the number of cases increasing. Sabah has experienced several HFMD outbreaks, but information on the epidemiology and molecular characteristics of responsible viruses is scarce. In this study, data of 17,574 reports of HFMD cases in Sabah from 2015 to 2019 were extracted from a public health disease surveillance system and analyzed. Twenty-one swab samples from 13 children were collected from Beaufort, Sabah, during an outbreak in August 2018 for detection and serotyping of causative viruses by semi-nested reverse transcription-polymerase chain reaction (snRT-PCR) of the VP4–VP2 region and consensus degenerate hybrid oligonucleotide primer PCR of the VP1 region, respectively. Nucleotide sequencing and phylogenetic analysis were conducted by the neighbor-joining method. The average annual incidence of HFMD was 94.3 per 100,000 people, with the greatest yearly increase between 2017 and 2018. Swabs from six children were tested positive for enterovirus, of which five were positive for CVA16 and one for EV71. All CVA16 strains belonged to sub-genotype B1a, and the EV71 strain belonged to sub-genotype B5. Phylogenetic analyses indicate that enterovirus genotype shift might be responsible for the increasing trend of HFMD in Sabah, however, further study is needed.