Isolation and molecular detection of dengue and chikungunya virus from field-collected adult mosquitoes in Kelantan, Malaysia.

BACKGROUND OBJECTIVES: Dengue and chikungunya infections are one of the major health problems that have plagued the human population globally. All dengue virus (DENV) serotypes circulate within Malaysia with particular serotypes dominating in different years/outbreaks. In the state of Kelantan, an increasing number of DENV and chikungunya virus (CHIKV) new cases have been reported, including several deaths. This study aimed to isolate and detect these arboviruses from adult mosquitoes in Kelantan. METHODS: Adult mo squito samples were collected from January to August 2019 and were identified according to gender, species and locality. The isolation of the virus was done in C6/36 cells. Dengue NS1 antigen was carried out using direct mosquito lysate and mosquito culture supernatant. Detection and serotyping of the DENV was performed using multiplex RT-PCR and CHIKV detection using a one-step RT-PCR assay. RESULTS: Of 91 mosquito pools, four were positive for NS1 antigen comprising two pools (2.2%) of male Ae. albopictus (Pulau Melaka and Kubang Siput) and two pools (2.2%) of Ae. aegypti (Kampung Demit Sungai). DENV 1 was detected in one pool (0.9%) of female Ae. albopictus among 114 tested Aedes pools. Two pools of 114 pools (1.7%) from both male Aedes species were positive with double serotypes, DENV 1 and DENV 2 (Pulau Melaka). However, no pool was positive for CHIKV. INTERPRETATION CONCLUSION: The presence of DENV and the main vectors of arboviruses in Kelantan are pertinent indicators of the need to improve vector controls to reduce arbovirus infections among people in the localities.

Prevalence of Vancomycin-Resistant Enterococcus (VRE) in Poultry in Malaysia: The First Meta-Analysis and Systematic Review.

Databases such as PubMed, Scopus and Google Scholar were searched. Data extraction and assessment of study protocol was done by two independent reviewers and the results were reviewed by a third. OpenMeta analyst and comprehensive meta-analysis (CMA) were used for the meta-analysis. The random effect model was used, publication bias and between-study heterogeneity was assessed. Seventeen studies were added to the final meta-analysis. Studies were sampled from 2000-2018 and of the 8684 isolates tested, 2824 were VRE. The pooled prevalence of VRE among poultry in Malaysia was estimated at 24.0% (95% CI; 16.7-33.1%; I2 = 98.14%; p < 0.001). Between-study variability was high (t2 = 0.788; heterogeneity I2 = 98.14% with heterogeneity chi-square (Q) = 858.379, degrees of freedom (df) = 16, and p < 0.001). The funnel plot showed bias which was confirmed by Egger's test and estimates from the leave-one-out forest plot did not affect the pooled prevalence. Pooled prevalence of VRE in chickens and ducks were 29.2% (CI = 18.8-42.5%) and 11.2%, CI = 9.0-14.0%) respectively. Enterococcus faecalis was reported most with more studies being reported in Peninsular Malaysia Central region and used antibiotic disc diffusion as detection method. Increased surveillance of VRE in poultry in Malaysia is required.

An evaluation of the World Health Organization's 1997 and 2009 dengue classifications in hospitalized dengue patients in Malaysia.

INTRODUCTION: The latest revised version of the World Health Organization's dengue classification was released in 2009. A handful of studies have taken initiatives to evaluate the old and revised guidelines to determine early signs and symptoms of severe dengue. This retrospective study aimed to compare the classification of dengue using both the 1997 and 2009 guidelines in a selected cohort of dengue patients from Peninsular Malaysia between 2008 and 2012. METHODOLOGY: Adult dengue patients were recruited from tertiary hospitals in two different states, Selangor and Kelantan, in Peninsular Malaysia. Their clinical manifestations were assessed. RESULTS: A total of 281 confirmed dengue patients were enrolled; the mean duration of illness at admission was five days. Of these, 88.6%, 10.7%, and 0.7% were classified according to the 1997 guidelines as having dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS), respectively. When the WHO 2009 guidelines were applied, 17.1%, 78.3%, and 4.6% were classified as dengue without warning signs, dengue with warning signs, and severe dengue, respectively. CONCLUSIONS: Our data suggests that the revised WHO 2009 guidelines stratify a much larger proportion of patients into a category that requires a higher level of medical and nursing care.

Fatal persistence of West Nile virus subtype Kunjin in the brains of flavivirus resistant mice.

Flaviviruses cause febrile illnesses in humans that may progress to encephalitis and death. Both viral and host factors determine the level of virus replication and outcome of infection. In mice, genetically determined resistance conferred by the flavivirus resistance locus (Flv) is responsible for the restricted flavivirus replication and prevention of disease development. Majority of flaviviruses express significant virulence, replicate to high titers and cause high mortality in susceptible mice, while congenic resistant mice endure the infection, show significantly reduced levels of virus replication and remain healthy. In contrast, infection with West Nile virus subtype Kunjin (KUNV) causes morbidity and fatal outcomes even in mice that are naturally resistant to flaviviruses. There are two possible mechanisms that could account for such an unforeseen virulence of KUNV in resistant mice: (a) an abrogation of Flv-controlled natural resistance leading to high virus replication, or (b) massive virus-induced immunopathology in the brain. To identify the cause(s) of fatality of KUNV infection, disease progression, virus replication and brain histopathology were studied in parallel in resistant and congenic susceptible mice. While KUNV replicated to high titers causing early fatalities in susceptible mice, it showed only reduced replication associated with the delayed morbidity in resistant mice indicating no abrogation of the Flv resistance. No evidence of excessive immune cell infiltration and tissue damage following KUNV infection were found. However, incomplete KUNV clearance not previously described was perceived as an important source of pathogenesis in resistant mice.