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Fulltext Multiplex real-time RT-PCR assay for diagnosis of Dengue, Zika and Chikungunya infections

Zarina Mohd Zawawi, Tengku Rogayah Tengku Abdul Rashid, Amir Hussien Adiee, Murni Maya Sari, Ravindran Thayan

Malaysian Journal of Medicine and Health Sciences, 2019;15(106):5-5.
MyJurnal

Introduction: Dengue virus (DENV), Zika virus (ZIKV) and Chikungunya virus (CHIKV) are Arboviruses that are transmitted by the same vector, Aedes aegypti. Dengue has become a global problem since the Second World War and is common in more than 110 countries. In Malaysia, dengue is a major disease burden as total economic costs to the country as a result of dengue is close to RM1.05 billion in 2010 and estimated to rise to 1.3 billion by 2020. Apart from Dengue, Zika and Chikungunya are the other important mosquito borne diseases in Malaysia. The aim of this study was to develop a multiplex real-time assay for simultaneous detection of DENV, ZIKV and CHIKV in clinical specimens. Methods: The published singleplex protocols were used with key modifications to implement a triplex assay. A one-step multiplex real-time RT-PCR assay was developed that can simultaneously detect RNA of DENV, ZIKV and CHIKV with good performance for a routine diagnostic use. The assay was evaluated for inter- and intra-reproducibility by mean CT value. The diagnostic sensitivity was tested with 135 archived samples which had been defined positive or negative by routine singleplex assays. Whole blood, plasma and urines were used in this study. Results: Intra- and inter-reproducibility and sensitivity varied from 0.10% to 4.73% and from 0.45% to 5.98% for each virus respectively. The specificity of detection was 100%. The multiplex real-time RT-PCR assay showed concordance with test results performed by routine singleplex assays. No cross reaction was observed for any of the clinical samples. Conclusion: The development of a rapid, sensitive and specific molecular assay for DENV, ZIKV and CHIKV infections will produce a greater diagnostic capacity in our laboratory. This multiplex approach is cost effective and robust with the concurrent detection of 3 viruses of public health concern.

Matched MeSH terms: Zika Virus Infection
Complete Genome Sequences of Three Historically Important, Spatiotemporally Distinct, and Genetically Divergent Strains of Zika Virus: MR-766, P6-740, and PRVABC-59

Yun SI, Song BH, Frank JC, Julander JG, Polejaeva IA, Davies CJ, et al.

Genome Announc, 2016;4(4).
PMID: 27540058 DOI: 10.1128/genomeA.00800-16

Here, we report the 10,807-nucleotide-long consensus RNA genome sequences of three spatiotemporally distinct and genetically divergent Zika virus strains, with the functionality of their genomic sequences substantiated by reverse genetics: MR-766 (African lineage, Uganda, 1947), P6-740 (Asian lineage, Malaysia, 1966), and PRVABC-59 (Asian lineage-derived American strain, Puerto Rico, 2015).

Matched MeSH terms: Zika Virus Infection
Fulltext Functional Genomics and Immunologic Tools: The Impact of Viral and Host Genetic Variations on the Outcome of Zika Virus Infection

Yun SI, Song BH, Frank JC, Julander JG, Olsen AL, Polejaeva IA, et al.

Viruses, 2018 08 11;10(8).
PMID: 30103523 DOI: 10.3390/v10080422

Zika virus (ZIKV) causes no-to-mild symptoms or severe neurological disorders. To investigate the importance of viral and host genetic variations in determining ZIKV infection outcomes, we created three full-length infectious cDNA clones as bacterial artificial chromosomes for each of three spatiotemporally distinct and genetically divergent ZIKVs: MR-766 (Uganda, 1947), P6-740 (Malaysia, 1966), and PRVABC-59 (Puerto Rico, 2015). Using the three molecularly cloned ZIKVs, together with 13 ZIKV region-specific polyclonal antibodies covering nearly the entire viral protein-coding region, we made three conceptual advances: (i) We created a comprehensive genome-wide portrait of ZIKV gene products and their related species, with several previously undescribed gene products identified in the case of all three molecularly cloned ZIKVs. (ii) We found that ZIKV has a broad cell tropism in vitro, being capable of establishing productive infection in 16 of 17 animal cell lines from 12 different species, although its growth kinetics varied depending on both the specific virus strain and host cell line. More importantly, we identified one ZIKV-non-susceptible bovine cell line that has a block in viral entry but fully supports the subsequent post-entry steps. (iii) We showed that in mice, the three molecularly cloned ZIKVs differ in their neuropathogenicity, depending on the particular combination of viral and host genetic backgrounds, as well as in the presence or absence of type I/II interferon signaling. Overall, our findings demonstrate the impact of viral and host genetic variations on the replication kinetics and neuropathogenicity of ZIKV and provide multiple avenues for developing and testing medical countermeasures against ZIKV.

Matched MeSH terms: Zika Virus Infection/genetics*; Zika Virus Infection/virology
Fulltext Possible Roles of New Mutations Shared by Asian and American Zika Viruses

Yokoyama S, Starmer WT

Mol Biol Evol, 2017 03 01;34(3):525-534.
PMID: 28087772 DOI: 10.1093/molbev/msw270

Originating in Africa, the Zika virus (ZIKV) has spread to Asia, Pacific Islands and now to the Americas and beyond. Since the first isolation in 1947, ZIKV strains have been sampled at various times in the last 69 years, but this history has not been reflected in studying the patterns of mutation accumulation in their genomes. Implementing the viral history, we show that the ZIKV ancestor appeared sometime in 1930-1945 and, at that point, its mutation rate was probably less than 0.2 × 10-3/nucleotide site/year and subsequently increased significantly in most of its descendants. Sustaining a high mutation rate of 4 × 10-3/site/year throughout its evolution, the Ancestral Asian strain, which was sampled from a mosquito in Malaysia, accumulated 13 mutations in the 3'-untranslated region of RNA stem-loops prior to 1963, seven of which generate more stable stem-loop structures and are likely to inhibit cellular antiviral activities, including immune and RNA interference (RNAi) pathways. The seven mutations have been maintained in all Asian and American strains and may be responsible for serious medical problems we are facing today and offer testable hypotheses to examine their roles in molecular interactions during brain development.

Matched MeSH terms: Zika Virus Infection/virology*
Fulltext Zika virus infection in Malaysia: an epidemiological, clinical and virological analysis

Woon YL, Lim MF, Tg Abd Rashid TR, Thayan R, Chidambaram SK, Syed Abdul Rahim SS, et al.

BMC Infect Dis, 2019 Feb 13;19(1):152.
PMID: 30760239 DOI: 10.1186/s12879-019-3786-9

BACKGROUND: A major outbreak of the Zika virus (ZIKV) has been reported in Brazil in 2015. Since then, it spread further to other countries in the Americas and resulted in declaration of the Public Health Emergency of International Concern (PHEIC) by World Health Organization. In 2016, Singapore reported its first minor ZIKV epidemic. Malaysia shares similar ecological environment as Brazil and Singapore which may also favor ZIKV transmission. However, no ZIKV outbreak has been reported in Malaysia to date. This study aimed to discuss all confirmed ZIKV cases captured under Malaysia ZIKV surveillance system after declaration of the PHEIC; and explore why Malaysia did not suffer a similar ZIKV outbreak as the other two countries.
METHODS: This was an observational study reviewing all confirmed ZIKV cases detected in Malaysia through the ZIKV clinical surveillance and Flavivirus laboratory surveillance between June 2015 and December 2017. All basic demographic characteristics, co-morbidities, clinical, laboratory and outcome data of the confirmed ZIKV cases were collected from the source documents.
RESULTS: Only eight out of 4043 cases tested positive for ZIKV infection during that period. The median age of infected patients was 48.6 years and majority was Chinese. Two of the subjects were pregnant. The median interval between the onset of disease and the first detection of ZIKV Ribonucleic Acid (RNA) in body fluid was 3 days. Six cases had ZIKV RNA detected in both serum and urine samples. Phylogenetic analysis suggests that isolates from the 7 cases of ZIKV infection came from two clusters, both of which were local circulating strains.
CONCLUSION: Despite similar ecological background characteristics, Malaysia was not as affected by the recent ZIKV outbreak compared to Brazil and Singapore. This could be related to pre-existing immunity against ZIKV in this population, which developed after the first introduction of the ZIKV in Malaysia decades ago. A serosurvey to determine the seroprevalence of ZIKV in Malaysia was carried out in 2017. The differences in circulating ZIKV strains could be another reason as to why Malaysia seemed to be protected from an outbreak.

Matched MeSH terms: Zika Virus Infection
Attitudes towards Zika screening and vaccination acceptability among pregnant women in Malaysia

Wong LP, Alias H, Hassan J, AbuBakar S

Vaccine, 2017 10 13;35(43):5912-5917.
PMID: 28886944 DOI: 10.1016/j.vaccine.2017.08.074

The aim of this study was to examine the willingness of pregnant women to have prenatal screening for the Zika virus (ZIKV). Secondly, the study also assessed the acceptability of a hypothetical Zika vaccination and its association with the health belief model (HBM) constructs. A cross-sectional study was conducted from 4th October to 11th November 2016, among pregnant women who attended antenatal care at the University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The majority (81.8%) was willing to be tested for ZIKV and 78% felt that their spouse would be willing to be tested for ZIKV. A total of 94% expressed a willingness to receive a Zika vaccination if available. The participants expressed high perceived benefits of a ZIKV vaccination. Although many have a high perception of the severity of ZIKV, the proportion with a strong perception of their susceptibility to ZIKV was low. In the multivariate analysis of all the HBM constructs, cue-to-action, namely physician recommendation (odds ratio [OR]=2.288; 95% confidence interval [CI] 1.093-4.793) and recommendation from friends or relatives (OR=4.030; 95% CI 1.694-9.587), were significantly associated with a willingness to be vaccinated against ZIKV. The favourable response to a Zika vaccination implies that more research attention has to be given to develop a vaccine against ZIKV. Should the vaccine be available in the future, publicity and healthcare providers would play a vital role in ensuring vaccine uptake among pregnant women.

Matched MeSH terms: Zika Virus Infection/immunology*; Zika Virus Infection/prevention & control*
The Self-Regulation Model of Illness: Comparison between Zika and Dengue and Its Application to Predict Mosquito Prevention Behaviours in Malaysia, a Dengue-Endemic Country

Wong LP, Alias H, Aghamohammadi N, Sam IC, AbuBakar S

Int J Environ Res Public Health, 2016 12 06;13(12).
PMID: 27929451

Perceptions about illnesses may influence self-care and preventive health behaviours. Illness perceptions of the Zika virus (ZIKV) infection were investigated under the framework of the Self-Regulation Model of Illness. Illness perception differences between ZIKV and dengue fever were also examined. Lastly, associations between illness perceptions of ZIKV with mosquito prevention practices were studied. Samples were drawn from landline telephone numbers using computer-assisted telephone interviewing in Malaysia. A total of 567 respondents completed the survey between February 2015 and May 2016. The median and interquartile range (IQR) for the total six dimensions of illness perceptions score was higher for dengue (23.0 (IQR 17.0-28.0)) than ZIKV (20.0 (IRQ 11.0-28.0)), p < 0.001. Respondents who planned to have children (OR 1.670, 95% CI 1.035-2.694 vs. no intention to have children) and had friends or acquaintances who died of dengue (OR 2.372, 95% CI 1.300-4.327 vs. no friends who died of dengue) were more likely to have a higher total score for six illness perceptions for ZIKV compared to dengue. Multivariate analysis indicated that the best predictors for mosquito control practices after the ZIKV outbreak was declared a Public Health Emergency of International Concern, in descending order, were causes, control, timeline, and consequences dimensions of illness perception. Understanding the context in which a person perceives ZIKV may contribute to developing interventions that influence prevention behaviours.

Matched MeSH terms: Zika Virus Infection/psychology*
Monitoring Changes in Human Umbilical Vein Endothelial Cells upon Viral Infection Using Impedance-Based Real-Time Cell Analysis

Wong JE, Zainal N, AbuBakar S, Tan KK

J Vis Exp, 2023 May 05.
PMID: 37212555 DOI: 10.3791/64887

Endothelial cells line the inner surface of all blood and lymphatic vessels, creating a semi-permeable barrier regulating fluid and solute exchange between blood or lymph and their surrounding tissues. The ability of a virus to cross the endothelial barrier is an important mechanism that facilitates virus dissemination in the human body. Many viruses are reported to alter endothelial permeability and/or cause endothelial cell barrier disruption during infection, which is able to cause vascular leakage. The current study describes a real-time cell analysis (RTCA) protocol, using a commercial real-time cell analyzer to monitor endothelial integrity and permeability changes during Zika virus (ZIKV) infection of the human umbilical vein endothelial cells (HUVECs). The impedance signals recorded before and after ZIKV infection were translated to cell index (CI) values and analyzed. The RTCA protocol allows the detection of transient effects in the form of cell morphological changes during a viral infection. This assay could also be useful for studying changes in the vascular integrity of HUVECs in other experimental setups.

Matched MeSH terms: Zika Virus Infection*
Zika virus infection and Guillain-Barré syndrome: a review focused on clinical and electrophysiological subtypes

Uncini A, Shahrizaila N, Kuwabara S

J Neurol Neurosurg Psychiatry, 2017 03;88(3):266-271.
PMID: 27799296 DOI: 10.1136/jnnp-2016-314310

In 2016, we have seen a rapid emergence of Zika virus-associated Guillain-Barré syndrome (GBS) since its first description in a French-Polynesian patient in 2014. Current evidence estimates the incidence of GBS at 24 cases per 100 000 persons infected by Zika virus. This will result in a sharp rise in the number of GBS cases worldwide with the anticipated global spread of Zika virus. A better understanding of the pathogenesis of Zika-associated GBS is crucial to prepare us for the current epidemic. In this review, we evaluate the existing literature on GBS in association with Zika and other flavivirus to better define its clinical subtypes and electrophysiological characteristics, demonstrating a demyelinating subtype of GBS in most cases. We also recommend measures that will help reduce the gaps in knowledge that currently exist.

Matched MeSH terms: Zika Virus Infection/epidemiology
Fulltext Viral Determinants and Vector Competence of Zika Virus Transmission

Tham HW, Balasubramaniam V, Ooi MK, Chew MF

Front Microbiol, 2018;9:1040.
PMID: 29875751 DOI: 10.3389/fmicb.2018.01040

Zika virus (ZIKV) has emerged as a new global health threat. Since its first discovery in Zika forest in Uganda, this virus has been isolated from several mosquito species, including Aedes aegypti and Aedes albopictus. The geographical distribution of these mosquito species across tropical and subtropical regions has led to several outbreaks, including the recent pandemic in Brazil, followed by the Pacific islands and other areas of North and South America. This has gained attention of the scientific community to elucidate the epidemiology and transmission of ZIKV. Despite its strong attention on clinical aspects for healthcare professionals, the relationships between ZIKV and its principal vectors, A. aegypti and A. albopictus, have not gained substantial interest in the scientific research community. As such, this review aims to summarize the current knowledge on ZIKV tropism and some important mechanisms which may be employed by the virus for effective strategies on viral survival in mosquitoes. In addition, this review identifies the areas of research that should be placed attention to, for which to be exploited for novel mosquito control strategies.

Matched MeSH terms: Zika Virus Infection
Fulltext A reverse transcription loop-mediated isothermal amplification for broad coverage detection of Asian and African Zika virus lineages

Teoh BT, Chin KL, Samsudin NI, Loong SK, Sam SS, Tan KK, et al.

BMC Infect Dis, 2020 Dec 11;20(1):947.
PMID: 33308203 DOI: 10.1186/s12879-020-05585-4

BACKGROUND: Early detection of Zika virus (ZIKV) infection during the viremia and viruria facilitates proper patient management and mosquito control measurement to prevent disease spread. Therefore, a cost-effective nucleic acid detection method for the diagnosis of ZIKV infection, especially in resource-deficient settings, is highly required.
METHODS: In the present study, a single-tube reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed for the detection of both the Asian and African-lineage ZIKV. The detection limit, strain coverage and cross-reactivity of the ZIKV RT-LAMP assay was evaluated. The sensitivity and specificity of the RT-LAMP were also evaluated using a total of 24 simulated clinical samples. The ZIKV quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was used as the reference assay.
RESULTS: The detection limit of the RT-LAMP assay was 3.73 ZIKV RNA copies (probit analysis, P ≤ 0.05). The RT-LAMP assay detected the ZIKV genomes of both the Asian and African lineages without cross-reacting with other arthropod-borne viruses. The sensitivity and specificity of the RT-LAMP assay were 90% (95% CI = 59.6-98.2) and 100% (95% CI = 78.5-100.0), respectively. The RT-LAMP assay detected ZIKV genome in 9 of 24 (37.5%) of the simulated clinical samples compared to 10 of 24 (41.7%) by qRT-PCR assay with a high level of concordance (κ = 0.913, P

Matched MeSH terms: Zika Virus Infection/diagnosis*; Zika Virus Infection/epidemiology*; Zika Virus Infection/virology
Fulltext Knowledge and perception on blood safety issues among blood donors at the National Blood Centre: a pilot study [Abstract]

Tan PP, Mohamed Fauzi, H., Chang CT, Ahmad NH, Bahar B, Mangantig E, et al.

Malaysian Journal of Medicine and Health Sciences, 2019;15(102):54-54.
MyJurnal

ABSTRACTS FOR INTERNATIONAL HEALTH AND MEDICAL SCIENCES CONFERENCE 2019 (IHMSC 2019)
Held at Taylor’s University Lakeside Campus, Subang Jaya, Selangor, Malaysia, 8-9th March, 2019
Introduction: Unsafe blood products cause transfusion-transmissible infections among blood receivers. The knowledge and perception of blood donors is important as it is associated with their donation behaviour and hence the safety of blood products. There was no previous study that assessed the knowledge and perception on blood safety issues among blood donors to date. The objective of this study was to assess the knowledge and perception of blood
donors on blood safety issues.
Methods: This was a pilot study conducted to pilot test the self-developed questionnaire by the researchers. The questionnaire was available in the Malay language. One-hundred-thirty donors at the National Blood Centre were recruited to complete the self-administered questionnaire. Health sciences professionals, medical students and non-Malaysians were excluded in this study.
Results: A total of 130 donors comprising of 70 males (53.8%) and 60 females (46.2%) responded. The mean age of the respondents is 32.48±8.86 years. Most of the respondents were Malay (55.4%), single (49.2%), working in private sector (46.9%) and regular donor (68.5%). More than half of the respondents did not know that dengue, Zika and mad-cow disease can be contracted through blood transfusion. Ten percent of the respondents answered that bisexual people are eligible to donate blood. 40.7% of the donors agreed to check their HIV status through blood donation. Majority of the donors (60.7%) agreed that the donors’ blood is safe if the screening test is negative. Whereas, 33.9% of the donors disagreed that they shall be responsible if their blood causes infection.
Conclusion: Several knowledge gaps and inappropriate perception among the respondents were identified and these might affect the safety of the blood products. Targeted measures should be taken to rectify donors’ knowledge and perception in order to minimise inappropriate blood donor behaviours and reduce unsafe blood products.

Matched MeSH terms: Zika Virus Infection
Polysulfonate suramin inhibits Zika virus infection

Tan CW, Sam IC, Chong WL, Lee VS, Chan YF

Antiviral Res, 2017 07;143:186-194.
PMID: 28457855 DOI: 10.1016/j.antiviral.2017.04.017

Zika virus (ZIKV) is an arthropod-borne flavivirus that causes newborn microcephaly and Guillian-Barré syndrome in adults. No therapeutics are available to treat ZIKV infection or other flaviviruses. In this study, we explored the inhibitory effect of glycosaminoglycans and analogues against ZIKV infection. Highly sulfated heparin, dextran sulfate and suramin significantly inhibited ZIKV infection in Vero cells. De-sulfated heparin analogues lose inhibitory effect, implying that sulfonate groups are critical for viral inhibition. Suramin, an FDA-approved anti-parasitic drug, inhibits ZIKV infection with 3-5 log10 PFU viral reduction with IC50value of ∼2.5-5 μg/ml (1.93 μM-3.85 μM). A time-of-drug-addition study revealed that suramin remains potent even when administrated at 1-24 hpi. Suramin inhibits ZIKV infection by preventing viral adsorption, entry and replication. Molecular dynamics simulation revealed stronger interaction of suramin with ZIKV NS3 helicase than with the envelope protein. Suramin warrants further investigation as a potential antiviral candidate for ZIKV infection. Heparan sulfate (HS) is a cellular attachment receptor for multiple flaviviruses. However, no direct ZIKV-heparin interaction was observed in heparin-binding analysis, and downregulate or removal of cellular HS with sodium chlorate or heparinase I/III did not inhibit ZIKV infection. This indicates that cell surface HS is not utilized by ZIKV as an attachment receptor.

Matched MeSH terms: Zika Virus Infection/prevention & control*; Zika Virus Infection/virology
Fulltext Islamic perspective on elective abortion of Zika virus infected pregnant women

Syazwani Hamdan, Mohd Rahman Omar, Mohammad Naqib Hamdan, Ummu Aiman Faisal

Malaysian Journal of Medicine and Health Sciences, 2019;15(106):60-60.
MyJurnal

Introduction: Zika virus infection is caused by flavivirus virus and spread by Aedes mosquitoes. Since first report-ed in 1947, it spread to various countries especially in the equatorial region including Malaysia. The infection is non-fatal to an adult. However, the major risk of its infection is towards unborn baby when the mother is infected. The vertical transmission to the foetus possess various risks include the teratogenic effect that may lead to elective abortion. Thus, the objectives of this review are to discover about Zika virus and its effect on pregnant women and to evaluate Islamic perspective about elective abortion of Zika virus-infected women. Methods: This review was done through reviewing evidence from the journals, books and reports. The data were reviewed thematically according to the objectives. Results: Studies shown that Zika virus may cause miscarriage, preterm birth, microcephaly and other malformation known as Congenital Zika syndrome. This leads to a demand for elective abortion which raised Islamic ethical issue if it is permissible. In Islam, abortion is extremely prohibited once the foetus reached 120-day of con-ception unless it causes harm to the mother’s life. But, if the foetus age is less than 120-day, abortion is permissible when the pregnancy affects the mother’s health. Abortion due to foetal microcephaly and congenital malformation is prohibited. Conclusion: Effort must be taken to prevent the spread of Zika virus to reduce the need for an elective abortion through an education Muslim community regarding elective abortion.

Matched MeSH terms: Zika Virus Infection
Fulltext Zika Virus as Oncolytic Therapy for Brain Cancer: Myth or Reality?

Su KY, Balasubramaniam VRMT

Front Microbiol, 2019;10:2715.
PMID: 31824472 DOI: 10.3389/fmicb.2019.02715

The ability of self-replicating oncolytic viruses (OVs) to preferentially infect and lyse cancer cells while stimulating anti-tumor immunity of the host strongly indicates its value as a new field of cancer therapeutics to be further explored. The emergence of Zika virus (ZIKV) as a global health threat due to its recent outbreak in Brazil has caught the attention of the scientific community and led to the discovery of its oncolytic potential for the treatment of glioblastoma multiforme (GBM), the most common and fatal brain tumor with poor prognosis. Herein, we evaluate the neurotropism of ZIKV relative to the receptor tyrosine kinase AXL and its ligand Gas6 in viral entry and the RNA-binding protein Musashi-1 (MSI1) in replication which are also overexpressed in GBM, suggesting its potential for specific targeting of the tumor. Additionally, this review discusses genetic modifications performed to enhance safety and efficacy of ZIKV as well as speculates future directions for the OV therapy.

Matched MeSH terms: Zika Virus Infection
Novel development of Lecanicillium lecanii-based granules as a platform against malarial vector Anopheles culicifacies

Sogan N, Kala S, Kapoor N, Nagpal BN, Ramlal A, Nautiyal A

World J Microbiol Biotechnol, 2023 Apr 01;39(6):142.
PMID: 37004584 DOI: 10.1007/s11274-023-03570-y

Mosquitoes are infectious vectors for a wide range of pathogens and parasites thereby transmitting several diseases including malaria, dengue, Zika, Japanese encephalitis and chikungunya which pose a major public health concern. Mostly synthetic insecticides are usually applied as a primary control strategy to manage vector-borne diseases. However excessive and non-judicious usage of such chemically derived insecticides has led to serious environmental and health issues owing to their biomagnification ability and increased toxicity towards non-target organisms. In this context, many such bioactive compounds originating from entomopathogenic microbes serve as an alternative strategy and environmentally benign tool for vector control. In the present paper, the entomopathogenic fungus, Lecanicillium lecanii (LL) was processed to make the granules. Developed 4% LL granules have been characterized using the technique of Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The developed formulation was also subjected to an accelerated temperature study at 40 °C and was found to be stable for 3 months. Further, GCMS of the L. lecanii was also performed to screen the potential biomolecules present. The developed formulation was found to be lethal against Anopheles culicifacies with an LC50 value of 11.836 µg/mL. The findings from SEM and histopathology also substantiated the mortality effects. Further, the SEM EDX (energy dispersive X-ray) studies revealed that the treated larvae have lower nitrogen content which is correlated to a lower level of chitin whereas the control ones has higher chitin content and healthy membranes. The developed LL granule formulation exhibited high toxicity against Anopheles mosquitoes. The granule formulations can be used as an effective biocontrol strategy against malaria-causing mosquitoes.

Matched MeSH terms: Zika Virus Infection*
Highly sensitive and specific graphene/TiO2 impedimetric immunosensor based on plant-derived tetravalent envelope glycoprotein domain III (EDIII) probe antigen for dengue diagnosis

Siew QY, Pang EL, Loh HS, Tan MTT

Biosens Bioelectron, 2021 Mar 15;176:112895.
PMID: 33358432 DOI: 10.1016/j.bios.2020.112895

This study reports on the development of a novel impedimetric immunosensor design using plant-derived antigenic glycoprotein for the detection of dengue virus (DENV) IgG antibodies. The electrochemical immunosensor platform was constructed using screen-printed carbon electrode (SPCE) modified with graphene/titanium dioxide (G/TiO2) nanocomposite to improve the electrode in terms electrochemical performance and specific surface area. A plant-derived dengue envelope domain III (EDIII) protein was used as the antigenic probe protein in this immunosensing strategy. Under optimised sensing conditions, the immunosensor demonstrated high sensitivity towards DENV IgG in a wide linear working range (62.5-2000 ng/mL), with a limit of detection of 2.81 ng/mL. The immunosensor showed high specificity for discriminating DENV IgG against antibodies of other infectious disease, including the closely related Zika virus (ZIKV). The reliability of the immunosensor in serological diagnosis was verified by challenging the immunosensor against serum samples, compared to conventional enzyme-linked immunosorbent assay (ELISA). As shown by its remarkable performance throughout the study, the devised immunosensor is proposed as a reliable and practical diagnostic tool for the serological detection of dengue in realistic applications.

Matched MeSH terms: Zika Virus Infection*
A graphene-based dengue immunosensor using plant-derived envelope glycoprotein domain III (EDIII) as the novel probe antigen

Siew QY, Tan SH, Pang EL, Loh HS, Tan MTT

Analyst, 2021 Mar 21;146(6):2009-2018.
PMID: 33523052 DOI: 10.1039/d0an02219e

The envelope glycoprotein domain III (EDIII) of dengue virus (DENV) has been recognised as the antigenic region responsible for receptor binding. In the present work, we have proposed a novel immunosensor constructed on a graphene-coated screen-printed carbon electrode (SPCE) using plant-derived EDIII as the probe antigen to target DENV IgG antibodies. The developed immunosensor demonstrated high sensitivity towards DENV IgG within a wide linear working range (125-2000 ng mL-1) under the optimised sensing conditions. The limit of detection was determined to be 22.5 ng mL-1. The immunosensor also showed high specificity towards DENV IgG, capable of differentiating DENV IgG from the antibodies of other infectious diseases including the similarly structured Zika virus (ZIKV). The ability of the immunosensor to detect dengue antibodies in serum samples was also verified by conducting tests on mouse serum samples. The proposed immunosensor was able to provide a binary (positive/negative) response towards the serum samples comparable to the conventional enzyme-linked immunosorbent assay (ELISA), indicating promising potential for realistic applications.

Matched MeSH terms: Zika Virus Infection*
Fulltext Association between Viral Infections and Risk of Autistic Disorder: An Overview

Shuid AN, Jayusman PA, Shuid N, Ismail J, Kamal Nor N, Mohamed IN

Int J Environ Res Public Health, 2021 Mar 10;18(6).
PMID: 33802042 DOI: 10.3390/ijerph18062817

Autism spectrum disorder (ASD) is a neurodevelopmental condition of the central nervous system (CNS) that presents with severe communication problems, impairment of social interactions, and stereotypic behaviours. Emerging studies indicate possible associations between viral infections and neurodegenerative and neurobehavioural conditions including autism. Viral infection during critical periods of early in utero neurodevelopment may lead to increased risk of autism in the offspring. This review is aimed at highlighting the association between viral infections, including viruses similar to COVID-19, and the aetiology of autism. A literature search was conducted using Pubmed, Ovid/Medline, and Google Scholar database. Relevant search terms included "rubella and autism", "cytomegalovirus and autism", "influenza virus and autism", "Zika virus and autism", "COVID-19 and autism". Based on the search terms, a total of 141 articles were obtained and studies on infants or children with congenital or perinatal viral infection and autistic behaviour were evaluated. The possible mechanisms by which viral infections could lead to autism include direct teratogenic effects and indirect effects of inflammation or maternal immune activation on the developing brain. Brain imaging studies have shown that the ensuing immune response from these viral infections could lead to disruption of the development of brain regions and structures. Hence, long-term follow up is necessary for infants whose mothers report an inflammatory event due to viral infection at any time during pregnancy to monitor for signs of autism. Research into the role of viral infection in the development of ASD may be one avenue of improving ASD outcomes in the future. Early screening and diagnosis to detect, and maybe even prevent ASD are essential to reduce the burden of this condition.

Matched MeSH terms: Zika Virus Infection*
Fulltext Field demonstration of the usefulness of a model of 3D printed mosquito light trap made in Sabah

Shigeharu Sato, Tomonori Hoshi, Bumpei Tojo, Samson Yodot, Joni Jain

Malaysian Journal of Medicine and Health Sciences, 2019;15(106):80-80.
MyJurnal

Introduction: Collecting mosquitoes is essential for research in mosquito-borne diseases, but the light traps used for that purpose are expensive and often difficult to obtain around research fields. We designed a new 3D-printable mosquito light trap that can be made inexpensively anywhere where electricity is available (Hoshi et al, Scientific Reports, in press). In this study, we produced that trap in Sabah and demonstrated its usefulness in the field. Meth-ods: With a 3D printer, the main parts of the trap - body, lid, lamp stand and collection box - were printed in Kota Kinabalu using black polylactic acid (PLA) filaments purchased online. All other parts such as the computer fan and batteries were commercially available at local shops in Sabah. The parts were assembled into the complete units at Universiti Malaysia Sabah’s Rural Medical Education Centre (RMEC) in Sikuati, Kudat. Demonstration was performed at two sites in the Kudat district: RMEC campus and the premises of a local farm in Kampung Paradason. Results: The 3D traps collected 6 and 7 different species of mosquitoes at RMEC and Paradason sites, respectively. The numbers of mosquito species collected by the commercially-available CDC model-512 traps in parallel experiments were 2 (RMEC) and 10 (Paradason). The species collected by the 3D traps included Aedes albopictus (vector transmitting Dengue virus), Anopheles barbumbrosus (malaria), Culex quinquefasciatus (Wuchereria bancrofti, avian malaria, and arboviruses including Japanese encephalitis and Zika viruses) and Mansonia indiana (Brugia malayi). Conclu-sion: The 3D light trap which was produced in Sabah demonstrated its usefulness in the field tests performed in the Kudat district. This model can be used as an alternative to the rather expensive commercial light traps to collect the vector insects transmitting mosquito-borne diseases such as malaria, dengue, Japanese encephalitis, Zika fever and filariasis.

Matched MeSH terms: Zika Virus Infection

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