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1.
J Med Virol ; 96(6): e29689, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38818789

RESUMEN

Individuals infected with dengue virus (DENV) often show no symptoms, which raises the risk of DENV transfusion transmission (TT-DENV) in areas where the virus is prevalent. This study aimed to determine the evidence of DENV infection in blood donors from different geographic regions of Thailand. A cross-sectional study was conducted on blood donor samples collected from the Thai Red Cross National Blood Center and four regional blood centers between March and September 2020. Screening for DENV nonstructural protein 1 (NS1), anti-DENV immunoglobulin G (IgG), and IgM antibodies was performed on residual blood from 1053 donors using enzyme-linked immunosorbent assay kits. Positive NS1 and IgM samples indicating acute infection were verified using four different techniques, including quantitative real-time (q) RT-PCR, nested PCR, virus isolation in C6/36 cells, and mosquito amplification. DENV IgG seropositivity was identified in 89% (938/1053) of blood donors. Additionally, 0.4% (4/1053) and 2.1% (22/1053) of Thai blood donors tested positive for NS1 and IgM, respectively. The presence of asymptomatic dengue virus infection in healthy blood donors suggests a potential risk of transmission through blood transfusion, posing a concern for blood safety.


Asunto(s)
Anticuerpos Antivirales , Donantes de Sangre , Virus del Dengue , Dengue , Inmunoglobulina G , Inmunoglobulina M , Humanos , Tailandia/epidemiología , Dengue/transmisión , Dengue/epidemiología , Donantes de Sangre/estadística & datos numéricos , Estudios Transversales , Virus del Dengue/inmunología , Virus del Dengue/aislamiento & purificación , Virus del Dengue/genética , Anticuerpos Antivirales/sangre , Femenino , Masculino , Adulto , Inmunoglobulina M/sangre , Inmunoglobulina G/sangre , Adulto Joven , Persona de Mediana Edad , Adolescente , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/inmunología , Donación de Sangre
2.
J Gen Virol ; 100(4): 629-641, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30869582

RESUMEN

There is growing evidence of the influence of sphingosine kinase (SK) enzymes on viral infection. Here, the role of sphingosine kinase 2 (SK2), an isoform of SK prominent in the brain, was defined during dengue virus (DENV) infection. Chemical inhibition of SK2 activity using two different SK2 inhibitors, ABC294640 and K145, had no effect on DENV infection in human cells in vitro. In contrast, DENV infection was restricted in SK2-/- immortalized mouse embryonic fibroblasts (iMEFs) with reduced induction of IFN-ß mRNA and protein, and mRNA for the IFN-stimulated genes (ISGs) viperin, IFIT1, IRF7 and CXCL10 in DENV-infected SK2-/- compared to WT iMEFs. Intracranial (ic) DENV injection in C57BL/6 SK2-/- mice induced body weight loss earlier than in WT mice but DENV RNA levels were comparable in the brain. Neither SK1 mRNA or sphingosine-1-phosphate (S1P) levels were altered following ic DENV infection in WT or SK2-/- mice but brain S1P levels were reduced in all SK2-/- mice, independent of DENV infection. CD8 mRNA was induced in the brains of both DENV-infected WT and SK2-/- mice, suggesting normal CD8+ T-cell infiltration into the DENV-infected brain independent of SK2 or S1P. Thus, although SK2 may be important for replication of some viruses SK2 activity does not affect DENV infection in vitro and SK2 or S1P levels do not influence DENV infection or T-cell infiltration in the context of infection in the brain.


Asunto(s)
Virus del Dengue/patogenicidad , Dengue/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Adamantano/análogos & derivados , Adamantano/farmacología , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/metabolismo , Linfocitos T CD8-positivos/virología , Línea Celular , Línea Celular Tumoral , Dengue/tratamiento farmacológico , Virus del Dengue/efectos de los fármacos , Células HEK293 , Células Hep G2 , Humanos , Interferón beta/metabolismo , Lisofosfolípidos/metabolismo , Ratones , Ratones Endogámicos C57BL , Piridinas/farmacología , ARN Mensajero/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Tiazolidinedionas/farmacología
3.
BMC Public Health ; 17(Suppl 1): 433, 2017 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-28699557

RESUMEN

BACKGROUND: In the Mexican state of Guerrero, some households place fish in water storage containers to prevent the development of mosquito larvae. Studies have shown that larvivorous fish reduce larva count in household water containers, but there is a lack of evidence about whether the use of fish is associated with a reduction in dengue virus infection. We used data from the follow up survey of the Camino Verde cluster randomised controlled trial of community mobilisation to reduce dengue risk to study this association. METHODS: The survey in 2012, among 90 clusters in the three coastal regions of Guerrero State, included a questionnaire to 10,864 households about socio-demographic factors and self-reported cases of dengue illness in the previous year. Paired saliva samples provided serological evidence of recent dengue infection among 4856 children aged 3-9 years. An entomological survey in the same households looked for larvae and pupae of Aedes aegypti and recorded presence of fish and temephos in water containers. We examined associations with the two outcomes of recent dengue infection and reported dengue illness in bivariate analysis and then multivariate analysis using generalized linear mixed modelling. RESULTS: Some 17% (1730/10,111) of households had fish in their water containers. The presence of fish was associated with lower levels of recent dengue virus infection in children aged 3-9 years (OR 0.64; 95% CI 0.45-0.91), as was living in a rural area (OR 0.57; 95% CI 0.45-0.71), and being aged 3-5 years (OR 0.65; 95% CI 0.51-0.83). Factors associated with lower likelihood of self-reported dengue illness were: the presence of fish (OR 0.79; 95% CI 0.64-0.97), and living in a rural area (OR 0.74; 95% CI 0.65-0.84). Factors associated with higher likelihood of self-reported dengue illness were: higher education level of the household head (OR 1.28; 95% CI 1.07-1.52), living in a household with five people or less (OR 1.33; 95% CI 1.16-1.52) and household use of insecticide anti-mosquito products (OR 1.68; 95% CI 1.47-1.92). CONCLUSIONS: Our study suggests that fish in water containers may reduce the risk of dengue virus infection and dengue illness. This could be a useful part of interventions to control the Aedes aegypti vector.


Asunto(s)
Aedes/crecimiento & desarrollo , Dengue/prevención & control , Composición Familiar , Peces , Control de Mosquitos/métodos , Abastecimiento de Agua , Agua , Animales , Niño , Preescolar , Estudios Transversales , Humanos , Insectos Vectores , Insecticidas , Larva , México , Oportunidad Relativa , Pupa , Población Rural , Encuestas y Cuestionarios , Temefós
4.
J Infect Dis ; 214(7): 994-1000, 2016 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-27418050

RESUMEN

BACKGROUND: Asymptomatic dengue virus-infected individuals are thought to play a major role in dengue virus transmission. The efficacy of the recently approved quadrivalent CYD-TDV dengue vaccine against asymptomatic dengue virus infection has not been previously assessed. METHODS: We pooled data for 3 736 individuals who received either CYD-TDV or placebo at 0, 6, and 12 months in the immunogenicity subsets of 2 phase 3 trials (clinical trials registration NCT01373281 and NCT01374516). We defined a seroconversion algorithm (ie, a ≥4-fold increase in the neutralizing antibody titer and a titer of ≥40 from month 13 to month 25) as a surrogate marker of asymptomatic infection in the vaccine and placebo groups. RESULTS: The algorithm detected seroconversion in 94% of individuals with a diagnosis of virologically confirmed dengue between months 13 and 25, validating its discriminatory power. Among those without virologically confirmed dengue (n = 3 669), 219 of 2 485 in the vaccine group and 157 of 1 184 in the placebo group seroconverted between months 13 and 25, giving a vaccine efficacy of 33.5% (95% confidence interval [CI], 17.9%-46.1%) against asymptomatic infection. Vaccine efficacy was marginally higher in subjects aged 9-16 years (38.6%; 95% CI, 22.1%-51.5%). The annual incidence of asymptomatic dengue virus infection in this age group was 14.8%, which was 4.4 times higher than the incidence for symptomatic dengue (3.4%). CONCLUSIONS: The observed vaccine efficacy against asymptomatic dengue virus infections is expected to translate into reduced dengue virus transmission if sufficient individuals are vaccinated in dengue-endemic areas.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Enfermedades Asintomáticas/epidemiología , Vacunas contra el Dengue/inmunología , Virus del Dengue/inmunología , Dengue/epidemiología , Dengue/prevención & control , Adolescente , Anciano , Asia/epidemiología , Niño , Preescolar , Ensayos Clínicos Fase III como Asunto , Vacunas contra el Dengue/administración & dosificación , Femenino , Humanos , América Latina/epidemiología , Masculino , Placebos/administración & dosificación , Resultado del Tratamiento
5.
Biochem Biophys Res Commun ; 478(1): 410-416, 2016 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-27396621

RESUMEN

Dengue virus infection is one of the most common arthropod-borne viral diseases. A complex interplay between host and viral factors contributes to the severity of infection. The antiviral effects of three antibiotics, lomefloxacin, netilmicin, and minocycline, were examined in this study, and minocycline was found to be a promising drug. This antiviral effect was confirmed in all four serotypes of the virus. The effects of minocycline at various stages of the viral life cycle, such as during viral RNA synthesis, intracellular envelope protein expression, and the production of infectious virions, were examined and found to be significantly reduced by minocycline treatment. Minocycline also modulated host factors, including the phosphorylation of extracellular signal-regulated kinase1/2 (ERK1/2). The transcription of antiviral genes, including 2'-5'-oligoadenylate synthetase 1 (OAS1), 2'-5'-oligoadenylate synthetase 3 (OAS3), and interferon α (IFNA), was upregulated by minocycline treatment. Therefore, the antiviral activity of minocycline may have a potential clinical use against Dengue virus infection.


Asunto(s)
Virus del Dengue/efectos de los fármacos , Dengue/tratamiento farmacológico , Dengue/virología , Reposicionamiento de Medicamentos/métodos , Minociclina/administración & dosificación , Carga Viral/efectos de los fármacos , Antivirales/administración & dosificación , Relación Dosis-Respuesta a Droga , Células Hep G2 , Humanos , Resultado del Tratamiento , Carga Viral/fisiología
6.
Neuropathology ; 36(1): 3-16, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26303046

RESUMEN

Severe dengue disease is often associated with long-term neurological impairments, but it is unclear what mechanisms are associated with neurological sequelae. Previously, we demonstrated antibody-enhanced dengue disease (ADE) dengue in an immunocompetent mouse model with a dengue virus 2 (DENV2) antibody injection followed by DENV3 virus infection. Here we migrated this ADE model to Callithrix penicillata. To mimic human multiple infections of endemic zones where abundant vectors and multiple serotypes co-exist, three animals received weekly subcutaneous injections of DENV3 (genotype III)-infected supernatant of C6/36 cell cultures, followed 24 h later by anti-DENV2 antibody for 12 weeks. There were six control animals, two of which received weekly anti-DENV2 antibodies, and four further animals received no injections. After multiple infections, brain, liver, and spleen samples were collected and tissue was immunolabeled for DENV3 antigens, ionized calcium binding adapter molecule 1, Ki-67, TNFα. There were marked morphological changes in the microglial population of ADE monkeys characterized by more highly ramified microglial processes, higher numbers of trees and larger surface areas. These changes were associated with intense TNFα-positive immunolabeling. It is unclear why ADE should generate such microglial activation given that IgG does not cross the blood-brain barrier, but this study reveals that in ADE dengue therapy targeting the CNS host response is likely to be important.


Asunto(s)
Sistema Nervioso Central/patología , Dengue/patología , Inflamación/patología , Animales , Anticuerpos Antivirales/toxicidad , Barrera Hematoencefálica/patología , Callithrix , Virus del Dengue/inmunología , Hipocampo/patología , Inmunohistoquímica , Microglía/patología , Factor de Necrosis Tumoral alfa/metabolismo
7.
Cureus ; 16(6): e61863, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38978912

RESUMEN

Based on the examination of four distinct cases, this case series offers a thorough investigation of the intricate relationship between dengue fever and hepatitis A infection. Despite their distinct origins, both illnesses manifest overlapping clinical features, posing considerable diagnostic hurdles, particularly in endemic regions. The cases reveal consistent symptoms such as elevated fever, abdominal discomfort, jaundice, and irregular liver function test results, underscoring the intricate nature of an accurate diagnosis. Variations in age distribution and the severity of symptoms underscore the necessity for tailored treatment approaches. Diagnostic challenges stem from the similarity in clinical presentations and shared laboratory abnormalities, necessitating comprehensive serological assessments. Therapeutic strategies entail a multidisciplinary approach addressing both hepatic and systemic manifestations, with supportive measures ensuring favorable clinical outcomes. Despite the complexities involved, timely interventions facilitate gradual symptom amelioration and successful patient recovery. Informing clinical practice and directing public health actions, this case series provides insightful information about the diagnostic and treatment complications associated with co-occurring dengue fever and hepatitis A infection.

8.
Cureus ; 16(2): e53817, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38332997

RESUMEN

OBJECTIVE: This study focused on examining the clinical manifestations, disease severity, and outcomes among cases of dengue fever (DF) confirmed through serological testing. The study specifically targeted individuals admitted to a tertiary care hospital in Islamabad, Pakistan. METHODOLOGY: This prospective observational study at the Pakistan Institute of Medical Sciences, Islamabad, Pakistan, tracked 1,003 patients from admission to discharge or death between August 2022 and November 2023. Patients were monitored, and admission criteria were established based on the identification of warning signs. The data collection process encompassed gathering demographic information, documenting clinical symptoms, and utilizing a severity classification system for the disease. Outcome measures comprised the duration of critical illness, length of hospital stay, overall outcomes (discharge or mortality), and the assessment of complications. The collected data were analyzed using IBM Statistical Package for the Social Sciences (SPSS) software version 22.0 (IBM Corp., Armonk, NY). RESULTS: Baseline characteristics revealed a male predominance (67.8%), with an average age of 35.77 years, and common comorbidities such as hypertension (9.3%) and diabetes mellitus (7.3%). Dengue fever was most prevalent among patients whose blood group was B+ (15.0%). Nonstructural protein 1 (NS1) was positive in 73.4% of the cases. Fever was the predominant complaint in 98.0% of instances. Common bleeding manifestations included epistaxis, gum bleeding, and hematemesis. About 52.20% of cases were observed to have severe thrombocytopenia at admission. Hospital-related aspects demonstrated a mean stay of 3.35 days, a critical phase lasting 1.68 days, and rare complications like expanded dengue syndrome (2.2%). Encouragingly, 98.9% of patients were discharged, 0.4% were shifted, and 0.7% succumbed to the disease. CONCLUSION: This study comprehensively analyzes the demographic and clinical aspects of DF, emphasizing a male predominance and the fact that fever was the most common presenting complaint. The duration of hospitalization revealed a brief mean stay, a short critical phase, and low complication rates, with a high discharge rate suggesting positive outcomes.

9.
Cureus ; 16(2): e54074, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38481891

RESUMEN

Dengue fever, the most prevalent arbovirus disease, has a broad spectrum of clinical manifestations, ranging from asymptomatic to dengue hemorrhagic fever and dengue shock syndrome. Dengue fever has the potential to involve the nervous system. Acute transverse myelitis is a life-threatening complication of dengue fever, though rarely reported. We report a case of dengue fever-induced transverse myelitis in a 51-year-old male who presented with progressive paraplegia, sensory disturbance, and urinary retention preceded by a febrile illness, vomiting, and retro-orbital pain two weeks before. His serology was positive for immunoglobulin M (IgM) to dengue virus and non-structural protein (NS-1). Magnetic resonance imaging revealed hyperintense signals suggestive of acute transverse myelitis. After ruling out all other possible causes, a possible diagnosis of dengue fever-induced transverse myelitis was made. His condition improved gradually after starting methylprednisolone.

10.
Cureus ; 15(4): e37093, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37153319

RESUMEN

Dengue is a febrile viral illness transmitted by Aedes Aegypti mosquito, presenting with a range of clinical features including a mild febrile illness to a life-threatening hemorrhagic fever or shock syndrome. Additionally, dengue fever can present with atypical features with the involvement of multiple organ systems including the heart. Here, we report a case of a 35-year-old female with dengue fever who presented with chest pain and dyspnea and was diagnosed with perimyocarditis.

11.
Cureus ; 15(11): e48357, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38060741

RESUMEN

Background Dengue infection (DI) continues to rise in the Caribbean. Children are primarily affected by severe infection in this region. Parents thus play an essential role in identifying symptoms, seeking medical care, and preventing DI in their children. Grenada has been endemic to DI since 1956, and to date, no study has assessed the level of knowledge, attitude, and practices (KAP) among parents regarding DI. Objective To determine the level of parents' KAP and associated sociodemographic factors regarding DI in children in Grenada. Methods A quantitative cross-sectional study of 360 randomly selected parents attending postnatal and child-health clinics was conducted in Grenada. Parents completed a validated survey on demographic information and KAP regarding DI from September to December 2019. KAP scores were calculated and categorized as adequate or inadequate based on the percentage of correctly answered questions on the survey. Chi-square and logistic regression analyses were used to determine the level of KAP and associated sociodemographic factors among parents. Results Only 33.9% of parents had adequate knowledge regarding DI, which was independently associated with gender (p-value: 0.001, CI: 1.688-7.411), age (p-value: 0.001, CI: 0.037-0.443), occupation, education, and marital status. Nevertheless, most parents had a positive attitude toward DI prevention (56.4%) and practiced adequate prevention (73%) against DI. Higher education was independently associated with a positive attitude toward DI prevention (p-value: 0.013, CI: 0.190-0.825). However, no sociodemographic factors were associated with the prevention practices of DI. Conclusion This study revealed a low level of knowledge among parents, despite an adequate attitude and level of prevention against DI in Grenada. It identified specific groups, such as young, single parents of low educational status, as potential targets for educational campaigns to reduce DI-associated morbidity and mortality among Grenadian children.

12.
Cureus ; 15(11): e48285, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38058326

RESUMEN

Dengue is a prevalent arthropod-born viral disease with a wide spectrum of clinical presentations ranging from undifferentiated fever to a more severe form of the disease, dengue hemorrhagic fever, and dengue shock syndrome. However, atypical manifestations such as hepatic, neurological, cardiac, and kidney involvement are increasingly being reported, thus the term "expanded dengue syndrome". We report a series of cases with an atypical presentation of dengue fever marked by various cardiac manifestations, including cardiogenic shock secondary to myocardial involvement.

13.
Cureus ; 15(8): e43684, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37724240

RESUMEN

We present a case report detailing the medical history of a 53-year-old female who had a well-established 10-year history of idiopathic thrombocytopenic purpura (ITP). The patient presented with fever and gum bleeding, prompting a series of laboratory investigations. These examinations revealed concurrent thrombocytopenia and hemolytic anemia, alongside a positive test result for serum dengue IgM antibodies. Initial treatment for the patient involved intravenous administration of glucocorticoids and intravenous immunoglobulin. Regrettably, this therapeutic intervention did not yield a favorable response. Subsequent clinical developments, including the onset of generalized tonic-clonic seizures, raised suspicions of thrombotic thrombocytopenic purpura (TTP). A notable diagnostic indicator was the elevated PLASMIC score (platelet count; combined hemolysis variable; absence of active cancer; absence of stem-cell or solid-organ transplant; mean corpuscular volume; international normalized ratio; creatinine), reinforcing the consideration of TTP. To confirm the diagnosis, ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motifs 13) enzyme levels were assessed and found to be low. Consequently, the patient was diagnosed with TTP. Plasmapheresis was administered, resulting in a positive clinical response after two cycles. Notably, the patient experienced a resolution of thrombocytopenia and hemolytic anemia. Following successful treatment, the patient was discharged with a prescription for immunosuppressants. This case underscores the critical importance of including TTP as a potential differential diagnosis when encountering patients with chronic ITP. TTP is characterized by its acute and life-threatening nature, often deviating from the typical clinical presentation. The application of the PLASMIC score serves as a valuable tool in guiding decision-making processes when TTP is suspected.

14.
Cureus ; 15(11): e48109, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37920426

RESUMEN

Infection with the dengue virus can present with a variety of clinical manifestations that can range from asymptomatic or mild disease to severe hemorrhagic shock. In this report, we present a 25-year-old female patient with complaints of fever, headache, vomiting, and a reeling sensation for two days. On further examination, the workup for meningitis was negative, and the patient tested positive for dengue IgM antibodies. The MRI brain showed a restricted central lesion involving the splenium of the corpus callosum in favor of a cytotoxic lesion of the corpus callosum and a transient lesion of the splenium. Based on the MRI, a diagnosis of reversible splenial lesion syndrome (RESLES) was confirmed. Supportive treatment was initiated, and the patient made a complete recovery with no neurological deficits. A repeat MRI of the brain was done one month later, and it revealed complete resolution of the splenial lesion. If dengue fever is treated effectively, it frequently has a favorable prognosis with remission of uncommon, distinct radiological associations.

15.
Cureus ; 15(11): e49338, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38143708

RESUMEN

A 63-year-old male patient recovering from dengue came to our department for contrast-enhanced computed tomography (CECT) for the evaluation of abdominal pain. An ultrasound performed in the periphery diagnosed him with a rectus abscess. The CECT evaluation done in our department clarified that the collection in his rectus sheath was hemorrhagic and not infective, as previously thought. The patient was managed conservatively and recovered without complications. Like most infectious diseases, dengue is a disease of tropical countries. System-wise data collection processes are inadequate in many developing countries, which means complications and adverse effects of common diseases are not adequately captured. Furthermore, resource limitations restrict the availability of more expensive diagnostic tests to central locations. Peripherally located regions with lower purchasing capacity have greater access to relatively inexpensive tests. This causes deficits in the management of some common disease entities, like dengue. Considering these issues, it is important to optimize healthcare testing for low-resource settings. This can only be achieved with adequate sensitization of healthcare providers in diagnosis and management.

16.
Cureus ; 15(7): e41717, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37575782

RESUMEN

The recent emergence and re-emergence of viral infections transmitted by vectors, Zika, chikungunya, dengue, and others, is a cause for international concern. Here, we provide a summary of the current understanding of the transmission, clinical features, diagnosis, global burden, and the likelihood of future epidemics by these viruses. Arboviruses transmitted by mosquitoes are challenging to diagnose and can have surprising clinical complications. Dengue, chikungunya, and Zika are the most important diseases caused by arboviruses worldwide, especially in tropical and subtropical regions. These are transmitted to humans by day-biting Aedes aegypti and Aedes albopictus mosquitoes. In India, the increase in the incidence of dengue and chikungunya cases is primarily linked to the dissemination of Aedes aegypti. A rapid and accurate diagnosis is paramount for effectively controlling dengue outbreaks. As there is no vaccination or specific treatment available for these viruses, vector control is the only comprehensive solution available.

17.
Methods Mol Biol ; 2409: 3-9, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34709631

RESUMEN

This chapter describes the methods of propagation and titration for DENV-1 to -4, which are required for most of the experiments using live viruses. DENV does not reach titers as high as those of other viruses or as high as desired for their use in biological assays. Although DENV grows in many different cell lines derived from both vertebrate and invertebrate cells, the most common cell lines used for virus isolation and propagation are mosquito cells C6/36 from Aedes albopictus. Amongst several methods for virus quantification, plaque assay stands out as being very practical and inexpensive. This technique is carried out essentially to estimate virion density in a particular material, being extremely important when evaluating the effect of an antiviral treatment or antibody neutralization capacity, for example. In this assay, viral particles are serially diluted and added onto confluent cell monolayers immersed in a semisolid medium, which is responsible for limiting virus spread throughout the culture. Therefore, regarding the medium consistency, once a virion successfully infects a cell, the newly produced particles can only infect neighboring cells, eventually leading them to death. This phenomenon can be observed as round gaps or plaques in the culture after staining live cells with a crystal violet solution. Then, plaques are counted and used to determine plaque-forming units per milliliter. Here, we describe a protocol established by our group for dengue virus (DENV) titration with porcine kidney (PS) cells.


Asunto(s)
Virus del Dengue , Dengue , Aedes , Animales , Antivirales , Bioensayo , Línea Celular , Porcinos
18.
Photodiagnosis Photodyn Ther ; 40: 103136, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36195260

RESUMEN

The dengue virus (DENV) infection is a worldwide cause of serious illness and death. Early and efficient prediction of disease may help in proper medical management to control disease. Keeping this in view, multivariate classification models by combining with Raman spectroscopy have been developed for the diagnosis of DENV infection in human blood sera. For study design, a statistical analysis is performed to select the sample size for training of models. Total 1240 Raman spectra have been acquired from 39 DENV infected and 23 healthy sera samples. Prior to model development, Raman spectra were examined using ANOVA test for significant differences present in the intensities of newly appeared Raman bands at 622, 645, 700, 746, 800, 814, 873, 890, 948, 1002, 1018, 1080, 1235, 1250, 1272, 1386, 1404, 1446, 1609 and 1645 cm-1. The significant differences and characteristic patterns of Raman bands induced by disease played decisive role and are exploited for development of multivariate model. Classification models are developed by utilizing principal component analysis (PCA) to extract discriminant features from multidimensional Raman spectral dataset and followed by support vector machines (SVM) with Polynomial of 5, RBF, and liner kernels. The proposed model for this study is built using 10-fold cross validation technique and evaluated on independent dataset to demonstrate its robustness. PCA-SVM (poly-5) model successfully yielded high diagnostic accuracy of 99.52%, sensitivity of 99.75%, specificity of 99.09% for classification of unknown suspected samples. For comparison, PCA discriminant analysis (PCA-DA), partial least squares regression (PLSR) are PLS-DA have been compared. It is found that PCA-SVM (poly-5) approach is more effective and robust compared to other state-of-the-art approaches and it can be used for clinical prediction of DENV infection in human blood sera.


Asunto(s)
Fotoquimioterapia , Virosis , Humanos , Fotoquimioterapia/métodos , Análisis Discriminante , Análisis de los Mínimos Cuadrados , Análisis de Componente Principal , Espectrometría Raman/métodos , Máquina de Vectores de Soporte
19.
Cureus ; 14(11): e31877, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36579259

RESUMEN

The COVID-19 pandemic caused by SARS-CoV-2 spread across many countries between 2020 and 2022. The similarities in clinical presentation with other endemic diseases pose a challenge to physicians in effectively diagnosing and treating the infection. Approximately 129 nations have a risk of dengue infection, and more than 100 of those are endemic to dengue. During the COVID-19 pandemic, the number of dengue cases decreased in many countries owing to the isolation measures followed. However, the common clinical presentation between them has led to misdiagnosis. Both COVID-19 and dengue fever cause a surge in pro-inflammatory cytokines and chemokines, thus sharing a common pathophysiology. False positive serological test results also posed difficulty differentiating between COVID-19 and dengue fever. This review aims to compare the clinical features, pathophysiology, and immune response between dengue and COVID-19, to benefit public health management during the pandemic.

20.
Viruses ; 13(10)2021 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-34696472

RESUMEN

It has been hypothesized that the host, viral factors, and secreted cytokines (especially TNF-α) play roles in the pathogenesis of secondary dengue infections. Mass spectrometry-based proteomic screening of cytoskeleton fractions isolated from human endothelial (EA.hy926) cells upon dengue virus (DENV) infection and TNF-α treatment identified 450 differentially altered proteins. Among them, decreased levels of moesin, actin stress fiber rearrangements, and dot-like formations of vinculin were observed with western blot analyses and/or immunofluorescence staining (IFA). In vitro vascular permeability assays using EA.hy926 cells, seeded on collagen-coated transwell inserts, showed low levels of transendothelial electrical resistance in treated cells. The synergistic effects of DENV infection and TNF-α treatment caused cellular permeability changes in EA.hy926 cells, which coincided with decreasing moesin levels and the production of abnormal organizations of actin stress fibers and vinculin. Functional studies demonstrated moesin overexpression restored transendothelial permeability in DENV/TNF-α-treated EA.hy926 cells. The present study improves the understanding of the disruption mechanisms of cytoskeleton proteins in enhancing vascular permeability during DENV infection and TNF-α treatment. The study also suggests that these disruption mechanisms are major factors contributing to vascular leakage in severe dengue patients.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Dengue/metabolismo , Células Endoteliales/virología , Proteínas de Microfilamentos/metabolismo , Actinas/metabolismo , Permeabilidad Capilar , Citoesqueleto/metabolismo , Virus del Dengue/metabolismo , Humanos , Permeabilidad , Proteómica , Factor de Necrosis Tumoral alfa/metabolismo
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