Hepatitis E virus (HEV) infection is an emerging zoonotic viral disease, with an increasingly international public health challenge. Despite the concerns that the global disease burden may be underestimated. Therefore, evaluation of the disease epidemiology in South - eastern Asia through a systematic review will assist in unraveling the burden of the disease in the subregion. A priori protocol was prepared for the systematic review and followed by a literature search involving five electronic databases. Identified publications were screened for high quality studies and the elimination of bias and relevant data extracted. A total of 4157 citations were captured, and only 35 were included in the review. A wide range of HEV seroprevalence was recorded from 2% (urban blood donors in Malaysia) to 77.7% (lowland communities in Lao PDR). Sporadic HEV infection and epidemics were also detected in the subregion. Indicating hyperendemicity of the disease in South - eastern Asia.
Malaysia is a non-endemic country for hepatitis E virus (HEV) infection. However, seroprevalence as high as 50% among samples of aboriginal people were reported over two decades ago. A total of 207 samples collected from seven aboriginal villages in rural settlements across two states in Malaysia were analysed for anti-HEV IgG and IgM by an enzyme-linked immunoassay. Following the detection of anti-HEV seroprevalence, we organized health outreach to inform and educate the community. Qualitative interviews were conducted with individuals tested positive for anti-HEV antibodies. Data derived from interviews and observations were used to investigate possible lifestyle behaviours associated with HEV infection. Anti-HEV IgG was detected in six samples (5.9%) from the village of Dusun Kubur. Qualitative inquiry and observation study revealed poor dietary and household hygiene, contaminated food and water, contact with animal faeces, unsanitary and domestic waste disposal, and wildlife reservoirs could be the contributing factors for transmission and acquisition of HEV infection. Investigation during health outreach is important to provide insights for future empirical research and implementation for improvement of lifestyle behaviours among the aborigines. Managing the risk of HEV infection in the aborigines may reduce the risk of HEV transmission to the local communities.
The aim of this study was to develop a highly specific electrochemical DNA sensor using functionalized lead sulphide (PbS) quantum dots for hepatitis E virus genotype 3 (HEV3) DNA target detection. Functionalized-PbS quantum dots (QDs) were used as an electrochemical label for the detection of HEV3-DNA target by the technique of square wave anodic stripping voltammetry (SWASV). The functionalized-PbS quantum dots were characterized by UV-vis, FTIR, XRD, TEM and zeta potential techniques. As-prepared, functionalized-PbS quantum dots have an average size of 4.15 ± 1.35 nm. The detection platform exhibited LOD and LOQ values of 1.23 fM and 2.11 fM, respectively. HEV3-DNA target spiked serum is also reported.Graphical abstract.
Hepatitis E virus (HEV) has been frequently detected from pork liver and liver products, which can usually cause self-limiting diseases in healthy adults, yet may result in fatality in immunosuppressed groups. Nevertheless, there is so far no standardized method for HEV detection available from pork liver and/or liver products. The present study aimed to optimize the virus extraction method of HEV from raw pork liver, which is often consumed in Asia undercooked to avoid a grainy texture. By comparing different sample preparation protocols and by applying the selected protocol to 60 samples collected from Singapore retail markets, we demonstrated that homogenization of 0.25 g raw pork liver with FastPrep™ Lysing Matrix Y containing yttria-stabilized zircondium oxide beads in 2 ml tubes and with harsh mechanical force at 6 ms-1, 40 s/cycle, for 5 cycles with 300 s pause time after each cycle is promising in both releasing the potentially intracellular viruses and resulting in satisfactory virus recovery rates (> 1%). A high prevalence (52%) of HEV genome was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) from the 60 samples collected from Singapore retail markets imported from Indonesia, Australia and Malaysia. However, RNase treatment decreased the HEV prevalence to 33.3%, and all of the 20 positive samples were with high RT-qPCR Ct values above 35, suggesting that the positive RT-qPCR signals maybe largely due to the inactive viruses and/or exposed HEV RNA traces in raw pork liver products. Therefore, conscious care should be taken when interpreting molecular detection results of viruses from food samples to be correlated with public health risks.