Displaying publications 141 - 160 of 1490 in total

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  1. Rozilawati H, Faudzi AY, Rahidah AA, Azlina AH, Abdullah AG, Amal NM, et al.
    Indian J Med Res, 2011 Jun;133:670-3.
    PMID: 21727669
    Chikungunya infection has become a public health threat in Malaysia since the 2008 nationwide outbreaks. Aedes albopictus Skuse has been identified as the chikungunya vector in Johor State during the outbreaks. In 2009, several outbreaks had been reported in the State of Kelantan. Entomological studies were conducted in Kelantan in four districts, namely Jeli, Tumpat, Pasir Mas and Tanah Merah to identify the vector responsible for the virus transmission.
    Matched MeSH terms: Insect Vectors/virology*; Larva/virology; Culicidae/virology*
  2. Saad N, Alcalá-Briseño RI, Polston JE, Olmstead JW, Varsani A, Harmon PF
    Sci Rep, 2020 Jul 21;10(1):12043.
    PMID: 32694553 DOI: 10.1038/s41598-020-68654-3
    A growing number of metagenomics-based approaches have been used for the discovery of viruses in insects, cultivated plants, and water in agricultural production systems. In this study, sixteen blueberry root transcriptomes from eight clonally propagated blueberry plants of cultivar 'Emerald' (interspecific hybrid of Vaccinium corymbosum and V. darrowi) generated as part of a separate study on varietal tolerance to soil salinity were analyzed for plant viral sequences. The objective was to determine if the asymptomatic plants harbored the latent blueberry red ringspot virus (BRRV) in their roots. The only currently known mechanism of transmission of BRRV is through vegetative propagation; however, the virus can remain latent for years with some plants of 'Emerald' never developing red ringspot symptoms. Bioinformatic analyses of 'Emerald' transcriptomes using de novo assembly and reference-based mapping approaches yielded eight complete viral genomes of BRRV (genus Soymovirus, family Caulimoviridae). Validation in vitro by PCR confirmed the presence of BRRV in 100% of the 'Emerald' root samples. Sequence and phylogenetic analyses showed 94% to 97% nucleotide identity between BRRV genomes from Florida and sequences from Czech Republic, Japan, Poland, Slovenia, and the United States. Taken together, this study documented the first detection of a complete BRRV genome from roots of asymptomatic blueberry plants and in Florida through in silico analysis of plant transcriptomes.
    Matched MeSH terms: Plant Diseases/virology*; Plant Roots/virology; Blueberry Plant/virology*
  3. Young LS, Yap LF, Murray PG
    Nat Rev Cancer, 2016 12;16(12):789-802.
    PMID: 27687982 DOI: 10.1038/nrc.2016.92
    It is more than 50 years since the Epstein-Barr virus (EBV), the first human tumour virus, was discovered. EBV has subsequently been found to be associated with a diverse range of tumours of both lymphoid and epithelial origin. Progress in the molecular analysis of EBV has revealed fundamental mechanisms of more general relevance to the oncogenic process. This Timeline article highlights key milestones in the 50-year history of EBV and discusses how this virus provides a paradigm for exploiting insights at the molecular level in the diagnosis, treatment and prevention of cancer.
    Matched MeSH terms: Lymphoma/virology; Neoplasms, Glandular and Epithelial/virology; Epstein-Barr Virus Infections/virology
  4. Wei F, Gaisa MM, D'Souza G, Xia N, Giuliano AR, Hawes SE, et al.
    Lancet HIV, 2021 Sep;8(9):e531-e543.
    PMID: 34339628 DOI: 10.1016/S2352-3018(21)00108-9
    BACKGROUND: Robust age-specific estimates of anal human papillomavirus (HPV) and high-grade squamous intraepithelial lesions (HSIL) in men can inform anal cancer prevention efforts. We aimed to evaluate the age-specific prevalence of anal HPV, HSIL, and their combination, in men, stratified by HIV status and sexuality.

    METHODS: We did a systematic review for studies on anal HPV infection in men and a pooled analysis of individual-level data from eligible studies across four groups: HIV-positive men who have sex with men (MSM), HIV-negative MSM, HIV-positive men who have sex with women (MSW), and HIV-negative MSW. Studies were required to inform on type-specific HPV infection (at least HPV16), detected by use of a PCR-based test from anal swabs, HIV status, sexuality (MSM, including those who have sex with men only or also with women, or MSW), and age. Authors of eligible studies with a sample size of 200 participants or more were invited to share deidentified individual-level data on the above four variables. Authors of studies including 40 or more HIV-positive MSW or 40 or more men from Africa (irrespective of HIV status and sexuality) were also invited to share these data. Pooled estimates of anal high-risk HPV (HR-HPV, including HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68), and HSIL or worse (HSIL+), were compared by use of adjusted prevalence ratios (aPRs) from generalised linear models.

    FINDINGS: The systematic review identified 93 eligible studies, of which 64 contributed data on 29 900 men to the pooled analysis. Among HIV-negative MSW anal HPV16 prevalence was 1·8% (91 of 5190) and HR-HPV prevalence was 6·9% (345 of 5003); among HIV-positive MSW the prevalences were 8·7% (59 of 682) and 26·9% (179 of 666); among HIV-negative MSM they were 13·7% (1455 of 10 617) and 41·2% (3798 of 9215), and among HIV-positive MSM 28·5% (3819 of 13 411) and 74·3% (8765 of 11 803). In HIV-positive MSM, HPV16 prevalence was 5·6% (two of 36) among those age 15-18 years and 28·8% (141 of 490) among those age 23-24 years (ptrend=0·0091); prevalence was 31·7% (1057 of 3337) among those age 25-34 years and 22·8% (451 of 1979) among those age 55 and older (ptrend<0·0001). HPV16 prevalence in HIV-negative MSM was 6·7% (15 of 223) among those age 15-18 and 13·9% (166 of 1192) among those age 23-24 years (ptrend=0·0076); the prevalence plateaued thereafter (ptrend=0·72). Similar age-specific patterns were observed for HR-HPV. No significant differences for HPV16 or HR-HPV were found by age for either HIV-positive or HIV-negative MSW. HSIL+ detection ranged from 7·5% (12 of 160) to 54·5% (61 of 112) in HIV-positive MSM; after adjustment for heterogeneity, HIV was a significant predictor of HSIL+ (aPR 1·54, 95% CI 1·36-1·73), HPV16-positive HSIL+ (1·66, 1·36-2·03), and HSIL+ in HPV16-positive MSM (1·19, 1·04-1·37). Among HPV16-positive MSM, HSIL+ prevalence increased with age.

    INTERPRETATION: High anal HPV prevalence among young HIV-positive and HIV-negative MSM highlights the benefits of gender-neutral HPV vaccination before sexual activity over catch-up vaccination. HIV-positive MSM are a priority for anal cancer screening research and initiatives targeting HPV16-positive HSIL+.

    FUNDING: International Agency for Research on Cancer.

    Matched MeSH terms: Anal Canal/virology*; HIV Infections/virology; Papillomavirus Infections/virology
  5. Zhang T, Wu Q, Zhang Z
    Curr Biol, 2020 Apr 06;30(7):1346-1351.e2.
    PMID: 32197085 DOI: 10.1016/j.cub.2020.03.022
    An outbreak of coronavirus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (SARS-CoV-2) began in the city of Wuhan in China and has widely spread worldwide. Currently, it is vital to explore potential intermediate hosts of SARS-CoV-2 to control COVID-19 spread. Therefore, we reinvestigated published data from pangolin lung samples from which SARS-CoV-like CoVs were detected by Liu et al. [1]. We found genomic and evolutionary evidence of the occurrence of a SARS-CoV-2-like CoV (named Pangolin-CoV) in dead Malayan pangolins. Pangolin-CoV is 91.02% and 90.55% identical to SARS-CoV-2 and BatCoV RaTG13, respectively, at the whole-genome level. Aside from RaTG13, Pangolin-CoV is the most closely related CoV to SARS-CoV-2. The S1 protein of Pangolin-CoV is much more closely related to SARS-CoV-2 than to RaTG13. Five key amino acid residues involved in the interaction with human ACE2 are completely consistent between Pangolin-CoV and SARS-CoV-2, but four amino acid mutations are present in RaTG13. Both Pangolin-CoV and RaTG13 lost the putative furin recognition sequence motif at S1/S2 cleavage site that can be observed in the SARS-CoV-2. Conclusively, this study suggests that pangolin species are a natural reservoir of SARS-CoV-2-like CoVs.
    Matched MeSH terms: Disease Reservoirs/virology*; Pneumonia, Viral/virology*; Coronavirus Infections/virology*
  6. Lee HL, Argubano RA, Ahmad R
    PMID: 9561626
    Matched MeSH terms: Aedes/virology*; Dengue/virology; Insect Vectors/virology*
  7. Ahmad R, Ismail A, Saat Z, Lim LH
    PMID: 9322296
    Mosquito adults and larvae were collected from dengue high risk areas and transported to the laboratory for identification. Identified mosquitos were pooled according to the species, date and locality and stored at -70 degrees C. A total of 1,385 pools of Aedes albopictus and 267 pools of Ae. Aegypti were collected from major towns in 12 states in Peninsular Malaysia. Virus isolation was carried out using cell culture (C6/36 clone) of Ae. albopictus and detection of dengue virus by the peroxidase anti-peroxidase staining. All positive isolations were further re-confirmed by the reverse transcriptase-polymerase chain reaction (RT-PCR). Most of the pools were negative with PAP staining and RT-PCR. However, 11 mosquito pools were positive with PAP staining. On the other hand, samples from Terengganu, Pulau Pinang and Johor were positive using both methods.
    Matched MeSH terms: Aedes/virology*; Larva/virology; Severe Dengue/virology
  8. Mabruk MJ, Sheahan B, Atkins G
    PMID: 16771222
    The effect of infection with teratogenic viruses at early stages of pregnancy is not fully understood. This study aimed to look at the effect of infection with teratogenic viruses such as bovine viral diarrhea virus (BVDV) and border disease virus (BDV), on early stage embryos at the hatched blastocyst stage. BVDV and BDV are known to cross the placenta of infected mothers and lead to congenital defects and death of developing fetuses. This study can be a good model for better understanding the effects of other teratogenic viruses such as Rubella virus in humans.
    Matched MeSH terms: Blastocyst/virology*; Border Disease/virology*; Bovine Virus Diarrhea-Mucosal Disease/virology*
  9. Thanarajoo SS, Kong LL, Kadir J, Lau WH, Vadamalai G
    J Virol Methods, 2014 Jun;202:19-23.
    PMID: 24631346 DOI: 10.1016/j.jviromet.2014.02.024
    A reverse transcription loop-mediated isothermal amplification (RT-LAMP) detected Coconut cadang-cadang viroid (CCCVd) within 60 min at 60 °C in total nucleic acid extracted from oil palm leaves infected with CCCVd. Positive reactions showed colour change from orange to green in the reaction mix after the addition of fluorescent reagent, and a laddering pattern band on 2% agarose gel electrophoresis. Conventional RT-PCR with LAMP primers produced amplicons with a sequence identical to the 297-nt CCCVd oil palm variant with the primers being specific for CCCVd and not for other viroids such as PSTVd and CEVd. RT-LAMP was found to be rapid and specific for detecting oil palm CCCVd.
    Matched MeSH terms: Cocos/virology*; Plant Diseases/virology*; Plant Leaves/virology
  10. Baseler L, de Wit E, Scott DP, Munster VJ, Feldmann H
    Vet Pathol, 2015 Jan;52(1):38-45.
    PMID: 25352203 DOI: 10.1177/0300985814556189
    Nipah virus is a paramyxovirus in the genus Henipavirus, which has caused outbreaks in humans in Malaysia, India, Singapore, and Bangladesh. Whereas the human cases in Malaysia were characterized mainly by neurological symptoms and a case fatality rate of ∼40%, cases in Bangladesh also exhibited respiratory disease and had a case fatality rate of ∼70%. Here, we compared the histopathologic changes in the respiratory tract of Syrian hamsters, a well-established small animal disease model for Nipah virus, inoculated oronasally with Nipah virus isolates from human cases in Malaysia and Bangladesh. The Nipah virus isolate from Bangladesh caused slightly more severe rhinitis and bronchointerstitial pneumonia 2 days after inoculation in Syrian hamsters. By day 4, differences in lesion severity could no longer be detected. Immunohistochemistry demonstrated Nipah virus antigen in the nasal cavity and pulmonary lesions; the amount of Nipah virus antigen present correlated with lesion severity. Immunohistochemistry indicated that both Nipah virus isolates exhibited endotheliotropism in small- and medium-caliber arteries and arterioles, but not in veins, in the lung. This correlated with the location of ephrin B2, the main receptor for Nipah virus, in the vasculature. In conclusion, Nipah virus isolates from outbreaks in Malaysia and Bangladesh caused a similar type and severity of respiratory tract lesions in Syrian hamsters, suggesting that the differences in human disease reported in the outbreaks in Malaysia and Bangladesh are unlikely to have been caused by intrinsic differences in these 2 virus isolates.
    Matched MeSH terms: Lung/virology; Respiratory System/virology; Henipavirus Infections/virology
  11. Yap G, Mailepessov D, Lim XF, Chan S, How CB, Humaidi M, et al.
    Am J Trop Med Hyg, 2020 09;103(3):1234-1240.
    PMID: 32700679 DOI: 10.4269/ajtmh.19-0377
    Mosquito-borne flaviviruses are emerging pathogens of an increasing global public health concern because of their rapid increase in geographical range and the impact of climate change. Japanese encephalitis virus (JEV) and West Nile virus (WNV) are of concern because of the risk of reemergence and introduction by migratory birds. In Singapore, human WNV infection has never been reported and human JEV infection is rare. Four sentinel vector surveillance sites were established in Singapore to understand the potential risk posed by these viruses. Surveillance was carried out from August 2011 to December 2012 at Pulau Ubin, from March 2011 to March 2013 at an Avian Sanctuary (AS), from December 2010 from October 2012 at Murai Farmway, and from December 2010 to December 2013 at a nature reserve. The present study revealed active JEV transmission in Singapore through the detection of JEV genotype II in Culex tritaeniorhynchus collected from an Avian Sanctuary. Culex flavivirus (CxFV), similar to the Quang Binh virus isolated from Cx. tritaeniorhynchus in Vietnam and CxFV-LSFlaviV-A20-09 virus isolated in China, was also detected in Culex spp. (vishnui subgroup). No WNV was detected. This study demonstrates the important role that surveillance plays in public health and strongly suggests the circulation of JEV among wildlife in Singapore, despite the absence of reported human cases. A One Health approach involving surveillance, the collaboration between public health and wildlife managers, and control of mosquito populations remains the key measures in risk mitigation of JEV transmission in the enzootic cycle between birds and mosquitoes.
    Matched MeSH terms: Culex/virology*; Encephalitis, Japanese/virology; Mosquito Vectors/virology*
  12. Rao M, Rashid FA, Sabri FSAH, Jamil NN, Seradja V, Abdullah NA, et al.
    J Med Virol, 2021 Apr;93(4):2461-2466.
    PMID: 33393672 DOI: 10.1002/jmv.26773
    An optimal clinical specimen for accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by minimizing the usage of consumables and reduce hazard exposure to healthcare workers is an urgent priority. The diagnostic performance of SARS-CoV-2 detection between healthcare worker-collected nasopharyngeal and oropharyngeal (NP + OP) swabs and patient performed self-collected random saliva was assessed. Paired NP + OP swabs and random saliva were collected and processed within 48 h of specimen collection from two cohort studies which recruited 562 asymptomatic adult candidates. Real-time reverse-transcription polymerase chain reaction targeting Open reading frame 1a (ORF1a) and nucleocapsid (N) genes was performed and the results were compared. Overall, 65 of 562 (28.1%) candidates tested positive for COVID-19 based on random saliva, NP + OP swabs, or both testing techniques. The detection rate of SARS-CoV-2 was higher in random saliva compared to NP + OP testing (92.3%; 60/65 vs. 73.8%; 48/65; p 
    Matched MeSH terms: Nasopharynx/virology; Oropharynx/virology*; Saliva/virology*
  13. Luby SP, Gurley ES
    PMID: 22752412 DOI: 10.1007/82_2012_207
    All seven recognized human cases of Hendra virus (HeV) infection have occurred in Queensland, Australia. Recognized human infections have all resulted from a HeV infected horse that was unusually efficient in transmitting the virus and a person with a high exposure to infectious secretions. In the large outbreak in Malaysia where Nipah virus (NiV) was first identified, most human infections resulted from close contact with NiV infected pigs. Outbreak investigations in Bangladesh have identified drinking raw date palm sap as the most common pathway of NiV transmission from Pteropus bats to people, but person-to-person transmission of NiV has been repeatedly identified in Bangladesh and India. Although henipaviruses are not easily transmitted to people, these newly recognized, high mortality agents warrant continued scientific attention.
    Matched MeSH terms: Chiroptera/virology; Fruit/virology; Horse Diseases/virology; Horses/virology; Arecaceae/virology; Henipavirus Infections/virology
  14. Stone R
    Science, 2011 Mar 4;331(6021):1128-31.
    PMID: 21385693 DOI: 10.1126/science.331.6021.1128
    Matched MeSH terms: Chiroptera/virology*; Pneumonia, Viral/virology; Encephalitis, Viral/virology; Arecaceae/virology*; Henipavirus Infections/virology*; Livestock/virology
  15. Ransangan J, Manin BO
    Vet Microbiol, 2010 Sep 28;145(1-2):153-7.
    PMID: 20427132 DOI: 10.1016/j.vetmic.2010.03.016
    Culture of Asian seabass, Lates calcarifer (Bloch) is a popular aquaculture activity in Malaysia. This fish is in high demand and fetches a good price in the local market. The seed for this fish is commercially produced by induced spawning in hatcheries. However, the seed supply is affected by frequent mass mortality of larvae aged between 15 and 60 dph. The clinical signs shown by the affected larvae include lethargy, loss of appetite, uncoordinated swimming, unusual spiral movement pattern and dark coloration. Histological examination of brain and eye of the affected specimens revealed extensive cell vacuolation in larvae aged 15-25 dph. Partial nucleotide sequence of the nervous necrosis virus coat protein gene of the affected larvae showed 94.0-96.1% homology to the nucleotide sequences of coat protein gene from nervous necrosis virus isolated from other countries in the Southeast Asia and Australia. This study provides scientific evidence based on molecular technique that many episodes of mass mortality in seabass larvae in Sabah is associated with the viral nervous necrosis. Because no effective treatment has been reported for this infection, stringent biosecurity measures must be adopted for exclusion of the pathogen from the culture system.
    Matched MeSH terms: Bass/virology*; Brain/virology; Fish Diseases/virology*; Larva/virology; Retina/virology; RNA Virus Infections/virology
  16. Yunos AM, Jaafar H, Idris FM, Kaur G, Mabruk MJ
    Mol Diagn Ther, 2006;10(4):251-6.
    PMID: 16884329
    Many studies in the literature have shown that Epstein-Barr virus (EBV) is associated with several human lymphoid and epithelial malignancies. However, the prevalence of EBV in non-Hodgkin lymphoma (NHL) of the lower gastrointestinal (GI) tract has not been fully elucidated.
    Matched MeSH terms: Intestinal Neoplasms/virology*; Intestine, Large/virology; Intestine, Small/virology; Lymphoma, Non-Hodgkin/virology*; Epstein-Barr Virus Infections/virology; Lower Gastrointestinal Tract/virology
  17. Gibbs WW
    Sci. Am., 1999 Aug;281(2):80-7.
    PMID: 10443039
    Matched MeSH terms: Brain/virology; Chiroptera/virology; Encephalitis, Japanese/virology; Swine/virology; Swine Diseases/virology; Paramyxoviridae Infections/virology
  18. Hooi YT, Ong KC, Tan SH, Perera D, Wong KT
    Lab Invest, 2020 Sep;100(9):1262-1275.
    PMID: 32601355 DOI: 10.1038/s41374-020-0456-x
    Coxsackievirus A16 (CV-A16) is one of the major causes of mild and self-limiting hand-foot-and-mouth disease (HFMD) in young children, which may occasionally leads to serious neurological complications. In this study, we had developed a novel, consistent, orally infected CV-A16 HFMD hamster model with encephalomyelitis. Four groups of 7-day-old hamsters in a kinetic study were orally infected with mouse-adapted CV-A16 strains and sacrificed at 1-4 days post infection (dpi), respectively. Tissues were studied by light microscopy, immunohistochemistry to detect viral antigens, in situ hybridization to detect viral RNA, and by viral titration. In a separate transmission experiment, orally infected index hamsters were housed together with contact hamsters to investigate oral and fecal viral shedding by virus culture and reverse transcription polymerase chain reaction (RT-PCR). At severe infection/death endpoints, index and contact hamster infection were also histopathologically analyzed. In the kinetic study, infected hamsters developed signs of infection at 4 dpi. Viral antigens/RNA were localized to brainstem (medulla/pons; reticular formation and motor trigeminal nucleus) and spinal cord anterior horn neurons, oral squamous epithelia and epidermis from 3 to 4 dpi. Salivary and lacrimal glands, myocardium, brown adipose tissue, intestinal smooth muscle, and skeletal muscle infection was also demonstrated. Viremia at 1 dpi and increasing viral titers in various tissues were observed from 2 dpi. In the transmission study, all contact hamsters developed disease 3-5 days later than index hamsters, but demonstrated similar histopathological findings at endpoint. Viral culture and RT-PCR positive oral washes and feces confirmed viral shedding. Our hamster model, orally infected by the natural route for human infection, confirmed CV-A16 neurotropism and demonstrated squamous epitheliotropism reminiscent of HFMD, attributes not found in other animal models. It should be useful to investigate neuropathogenesis, model person-to-person transmission, and for testing antiviral drugs and vaccines.
    Matched MeSH terms: Encephalomyelitis/virology*; Feces/virology; Cricetinae/virology*; Hand, Foot and Mouth Disease/virology*; Mouth/virology*; Mouth Mucosa/virology
  19. Chiam CW, Chan YF, Loong SK, Yong SS, Hooi PS, Sam IC
    Diagn Microbiol Infect Dis, 2013 Oct;77(2):133-7.
    PMID: 23886793 DOI: 10.1016/j.diagmicrobio.2013.06.018
    Quantitative real-time polymerase chain reaction (qRT-PCR) is useful for diagnosis and studying virus replication. We developed positive- and negative-strand qRT-PCR assays to detect nsP3 of chikungunya virus (CHIKV), a positive-strand RNA alphavirus that causes epidemic fever, rash, and arthritis. The positive- and negative-strand qRT-PCR assays had limits of quantification of 1 and 3 log10 RNA copies/reaction, respectively. Compared to a published E1 diagnostic assay using 30 laboratory-confirmed clinical samples, the positive-strand nsP3 qRT-PCR assay had higher R(2) and efficiency and detected more positive samples. Peak viral load of 12.9 log(10) RNA copies/mL was reached on day 2 of illness, and RNA was detectable up to day 9, even in the presence of anti-CHIKV IgM. There was no correlation between viral load and persistent arthralgia. The positive-strand nsP3 assay is suitable for diagnosis, while the negative-strand nsP3 assay, which uses tagged primers to increase specificity, is useful for study of active viral replication kinetics.
    Matched MeSH terms: Virology/methods; Alphavirus Infections/virology; Arthralgia/virology
  20. Enserink M
    Science, 1999 Apr 16;284(5413):407, 409-10.
    PMID: 10232977 DOI: 10.1126/science.284.5413.407
    Matched MeSH terms: Agricultural Workers' Diseases/virology; Swine/virology*; Swine Diseases/virology; Paramyxoviridae Infections/virology
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