8 research outputs found

    ELISA as an alternative tool for epidemiological surveillance for dengue in mosquitoes: a report from Thailand

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    Background & objectives: Dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shocksyndrome (DSS) are the re-emerging infectious diseases caused by the four serotypes of dengue(DEN) virus, type 1 to 4, belonging to the family Flaviviridae and genus Flavivirus. In the absenceof a safe and effective mass immunisation, the prevention and control of dengue outbreaks dependupon the surveillance of cases and mosquito vector. The aim of this work is to test enzyme-linkedimmunosorbent assay (ELISA) tool for the virological surveillance of dengue.Methods: Virus-infected Aedes mosquitoes were collected from the field in order to serve as anearly warning monitoring tool for dengue outbreaks. In a prospective field study conducted fromApril to September 2000, female adult Aedes mosquitoes were caught from selected dengue-sensitivearea in Chombung district, Ratchaburi province and assayed by ELISA.Result: Approximately 18.3% were found positive for dengue virus.Conclusion: This can imply that ELISA can be an alternative tool for epidemiological surveillancefor dengue in mosquitoes

    Cryptosporidium and Giardia detection in environmental waters of southwest coastal areas of Thailand

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    The aim of this study was to investigate water samples collected in coastal areas of Southern Thailand in the years of 2005 and 2008 for their contamination by the protozoan parasites Cryptosporidium and Giardia. One hundred eighteen water samples of different origin were collected from six Tsunami affected southern provinces of Thailand in early 2005, and they have been analyzed using standardized methodology. Fifteen out of 118 samples (12.7%) were positive for Cryptosporidium spp. and nine (7.6%) positive for Giardia spp. Additional 42 samples from two same areas were examined 3 years later, in the early 2008. Five out of 42 (11.9%) samples were positive for Cryptosporidium spp., and three out of 42 (7.1%) were positive for Giardia spp.. Both protozoans were found in reservoir, river/canal, and pond waters. It appears no significant differences (p \u3c 0.05) between Cryptosporidium and Giardia (oo)cysts levels during the two monitoring periods; however, the number of the investigated areas and samples in the second period was significantly less than in the first period. This is the first description on Cryptosporidium and Giardia (oo)cysts in water sources of Thailand, and it suggests the need for water quality control in the interest of public health safety

    Occurrence of Cryptosporidium oocysts in commercial oysters in southern Thailand

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    The enteric parasite Cryptosporidium is spread through the fecal-oral pathway, most commonly by the consumption of contaminated water but also through food. Because eating raw or barely cooked shellfish might put consumers at risk for cryptosporidiosis, identifying the parasite in oysters is important for public health. A total of 240 oysters, collected from two shellfish aquaculture sites in Thailand's Gulf coast, Nakhon Si Thammarat and Surat Thani, were tested for the presence of Cryptosporidium. Escherichia coli, enterococci, and thermotolerant coliform total levels were measured to assess seawater quality in the shellfish production regions. Oocysts of Cryptosporidium spp. were detected in 13.8% of the samples processed by immunofluorescence analyses. The detection of Cryptosporidium spp. oocysts in oysters obtained from Surat Thani (17.5%) was higher than in those obtained from Nakhon Si Thammarat (9.2%). The difference in detection of positive samples obtained from Nakhon Si Thammarat and those obtained from Surat Thani may be attributed to the effects of physical, ecological, and anthropogenic conditions, resulting in an increased level of marine water contamination by Cryptosporidium spp. oocysts. These findings demonstrate that native commercial oysters obtained from Thailand's southern Gulf coast contained Cryptosporidium spp. oocysts which might serve as a source of human infection. Consequently, these findings pose a serious public health concern and suggest that more quality control measures need to be implemented by the oyster aquaculture business to ensure the safety of seafood

    Prognostic Indicators for the Early Prediction of Severe Dengue Infection: A Retrospective Study in a University Hospital in Thailand

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    This study aimed to develop simple diagnostic guidelines which would be useful for the early detection of severe dengue infections. Retrospective data of patients with dengue infection were reviewed. Patients with diagnosed dengue infection were categorized in line with the International Statistical Classification of Diseases (ICD-10): A90, dengue fever; A91, dengue hemorrhagic fever; and A910, dengue hemorrhagic fever with shock. A total of 302 dengue-infected patients were enrolled, of which 136 (45%) were male and 166 (55%) were female. Multivariate analysis was conducted to determine independent diagnostic predictors of severe dengue infection and to convert simple diagnostic guidelines into a scoring system for disease severity. Coefficients for significant predictors of disease severity generated by ordinal multivariable logistic regression analysis were transformed into item scores. The derived total scores ranged from 0 to 38.6. The cut-off score for predicting dengue severity was higher than 14, with an area under the receiver operating curve (AUROC) of 0.902. The predicted positive value (PPV) was 68.7% and the negative predictive value (NPV) was 94.1%. Our study demonstrates that several diagnostic parameters can be effectively combined into a simple score sheet with predictive value for the severity evaluation of dengue infection

    Quercetin: A Functional Food-Flavonoid Incredibly Attenuates Emerging and Re-Emerging Viral Infections through Immunomodulatory Actions

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    Many of the medicinally active molecules in the flavonoid class of phytochemicals are being researched for their potential antiviral activity against various DNA and RNA viruses. Quercetin is a flavonoid that can be found in a variety of foods, including fruits and vegetables. It has been reported to be effective against a variety of viruses. This review, therefore, deciphered the mechanistic of how Quercetin works against some of the deadliest viruses, such as influenza A, Hepatitis C, Dengue type 2 and Ebola virus, which cause frequent outbreaks worldwide and result in significant morbidity and mortality in humans through epidemics or pandemics. All those have an alarming impact on both human health and the global and national economies. The review extended computing the Quercetin-contained natural recourse and its modes of action in different experimental approaches leading to antiviral actions. The gap in effective treatment emphasizes the necessity of a search for new effective antiviral compounds. Quercetin shows potential antiviral activity and inhibits it by targeting viral infections at multiple stages. The suppression of viral neuraminidase, proteases and DNA/RNA polymerases and the alteration of many viral proteins as well as their immunomodulation are the main molecular mechanisms of Quercetin’s antiviral activities. Nonetheless, the huge potential of Quercetin and its extensive use is inadequately approached as a therapeutic for emerging and re-emerging viral infections. Therefore, this review enumerated the food-functioned Quercetin source, the modes of action of Quercetin for antiviral effects and made insights on the mechanism-based antiviral action of Quercetin

    Quercetin: A Functional Food-Flavonoid Incredibly Attenuates Emerging and Re-Emerging Viral Infections through Immunomodulatory Actions

    No full text
    Many of the medicinally active molecules in the flavonoid class of phytochemicals are being researched for their potential antiviral activity against various DNA and RNA viruses. Quercetin is a flavonoid that can be found in a variety of foods, including fruits and vegetables. It has been reported to be effective against a variety of viruses. This review, therefore, deciphered the mechanistic of how Quercetin works against some of the deadliest viruses, such as influenza A, Hepatitis C, Dengue type 2 and Ebola virus, which cause frequent outbreaks worldwide and result in significant morbidity and mortality in humans through epidemics or pandemics. All those have an alarming impact on both human health and the global and national economies. The review extended computing the Quercetin-contained natural recourse and its modes of action in different experimental approaches leading to antiviral actions. The gap in effective treatment emphasizes the necessity of a search for new effective antiviral compounds. Quercetin shows potential antiviral activity and inhibits it by targeting viral infections at multiple stages. The suppression of viral neuraminidase, proteases and DNA/RNA polymerases and the alteration of many viral proteins as well as their immunomodulation are the main molecular mechanisms of Quercetin’s antiviral activities. Nonetheless, the huge potential of Quercetin and its extensive use is inadequately approached as a therapeutic for emerging and re-emerging viral infections. Therefore, this review enumerated the food-functioned Quercetin source, the modes of action of Quercetin for antiviral effects and made insights on the mechanism-based antiviral action of Quercetin
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