摘要 :
Background: Type 1 interferon (IFNα/β) has a significant role in establishing protection against virus infections. It has been well documented by in vitro studies that dengue virus (DENV) activates a robust IFNα/β response. Ho...
展开
Background: Type 1 interferon (IFNα/β) has a significant role in establishing protection against virus infections. It has been well documented by in vitro studies that dengue virus (DENV) activates a robust IFNα/β response. However, DENV also induces a down-regulation of the JAK/STAT pathway, inhibiting the induction of interferon regulated genes. As a consequence, the role played by the IFN type 1 response in the protection of dengue patients is not fully understood. Objective: To compare IFN-α levels in dengue patients with dengue fever (DF) or dengue hemorrhagic fever (DHF) undergoing primary or secondary infections. Study design: Two hundred and four serum samples were analyzed for IFN-α level by cytometric bead array. Patients' clinical condition was assigned following the WHO 1997 criteria and specific IgG and IgM antibodies were measured using commercial assays to determine primary and secondary infections. The infecting serotype was determined by qRT-PCR. Results and conclusion: The IFN-α levels were found significantly higher in DF than DHF patients irrespective of the infecting serotype (DENV1 or 2), and were found to decline rapidly at day 3 after fever onset. For DENV2 infections, higher IFN-α level was found during primary than secondary infections. These results suggest that an early strong interferon response correlates with a better clinical condition.
收起
摘要 :
Dengue virus (DENV), an arbovirus transmitted by mosquitoes, has become a major threat to American human life, reaching approximately 23 million cases from 1980 to 2017. Brazil is among the countries most affected by this terrible...
展开
Dengue virus (DENV), an arbovirus transmitted by mosquitoes, has become a major threat to American human life, reaching approximately 23 million cases from 1980 to 2017. Brazil is among the countries most affected by this terrible viral disease, with 13.6 million cases. DENV has four different serotypes, DENV1-4, which show a broad clinical spectrum. Dengue creates a staggering epidemiological and economic burden for endemic countries. Without a specific therapy and with a commercial vaccine that presents some problems relative to its full effectiveness, initiatives to improve vector control strategies, early disease diagnostics and the development of vaccines and antiviral drugs are priorities. In this study, we present the probable origins of dengue in America and the trajectories of its spread. Overall, dengue diagnostics are costly, making the monitoring of dengue epidemiology more difficult and affecting physicians' therapeutic decisions regarding dengue patients, especially in developing countries. This review also highlights some recent and important findings regarding dengue in Brazil and the Americas. We also summarize the existing DENV polymerase chain reaction (PCR) diagnostic tests to provide an improved reference since these tests are useful and accurate at discriminating DENV from other flaviviruses that co-circulate in the Americas. Additionally, these DENV PCR assays ensure virus serotyping, enabling epidemiologic monitoring.
收起
摘要 :
Dengue is a very rapidly growing public health problem being currently faced by ∼40% of the global population living in more than a hundred tropical and sub-tropical countries. It is a viral disease, caused by four types of dengu...
展开
Dengue is a very rapidly growing public health problem being currently faced by ∼40% of the global population living in more than a hundred tropical and sub-tropical countries. It is a viral disease, caused by four types of dengue viruses, transmitted by mosquitoes, to an estimated 50 million people each year. Vector control methods to contain transmission have not been successful and there is currently no useful diagnostic test, drug or vaccine to combat dengue disease. However, as a result of the heightened awareness of its magnitude and its potential to spread beyond the tropical world, dengue has begun to emerge out of the list of neglected diseases in recent years. New interest in this disease has drawn scientists from multiple disciplines into the dengue arena. This has resulted in novel insights into several aspects of dengue virus biology and identified potential drug targets. Several tetravalent vaccines are being developed. Newer animal models that mirror some of the salient features of dengue disease are becoming available to investigate the mechanism of pathogenesis and to aid in drug and vaccine discovery efforts. The realization that therapeutic and prophylactic intervention can be cost-effective has resulted in vigorous industry-driven translational initiatives to develop drugs and vaccines. Dengue research is at a critical juncture and the implementation of existing knowledge supplemented by a better understanding of pathogenesis promises to make a tangible impact in the combat against dengue in the coming years.
收起
摘要 :
Dengue is a mosquito-transmitted infection that poses significant global health risks for travelers and individuals living in the tropics and subtropics. The reported global incidence has increased dramatically in the past century...
展开
Dengue is a mosquito-transmitted infection that poses significant global health risks for travelers and individuals living in the tropics and subtropics. The reported global incidence has increased dramatically in the past century, with dengue now ranking as the most common cause of febrile illness in travelers. While sporadic cases have been reported within the southern United States since 1980, autochthonous outbreaks have now been described in Hawaii, St. Croix (US Virgin Islands), along the Texas-Mexico border, and, most recently, in Key West, Florida. Although many infections are mild or asymptomatic, 5-10% of patients may experience hemorrhagic disease, with shock and even death. Laboratory identification commonly involves serologic and nucleic acid amplification methods. Due to rising incidence worldwide, physicians should be familiar with the clinical manifestations, laboratory diagnosis, and management of this illness.
收起
摘要 :
Dengue is the most important and widely distributed arthropod-borne viral disease affecting humans. The number of dengue virus infections has steadily grown and more than 100 countries survey dengue incidence every year. Due to th...
展开
Dengue is the most important and widely distributed arthropod-borne viral disease affecting humans. The number of dengue virus infections has steadily grown and more than 100 countries survey dengue incidence every year. Due to the lack of an approved antiviral treatment or licensed preventative vaccine, accurate and opportune diagnosis is commended for efficient dengue epidemiological surveillance, to propose control measures in order to curtail outbreaks timely and treat patients satisfactorily. In this review, the basis, application and indications for different diagnostic tests are described, and their advantages and limitations considered. At the end of this piece, we speculate what the future may hold for the diagnosis of dengue infections.
收起
摘要 :
We admire the work of the investigators from Mexico for conducting a meticulous study on the comparison of the dengue virus (DENV) viral load and the circulating NS1 levels in patients who were positive or negative for dengue spec...
展开
We admire the work of the investigators from Mexico for conducting a meticulous study on the comparison of the dengue virus (DENV) viral load and the circulating NS1 levels in patients who were positive or negative for dengue specific IgM [1] and concur with their suggestion that during the initial phase of illness a detection of viral RNA rather than IgM would be more effective. We believe that similar studies on viral load are indicated on blood samples from patients with anomalous serologic response or any aberrant mode of disease spread.
收起
摘要 :
Abstract Objective To review the diagnostic test accuracy and predictive value of statistical models in differentiating the severity of dengue infection. Methods Electronic searches were conducted in the Cochrane Database of Syste...
展开
Abstract Objective To review the diagnostic test accuracy and predictive value of statistical models in differentiating the severity of dengue infection. Methods Electronic searches were conducted in the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE (complete), PubMed and Scopus. Eligible studies to be included in this review were cohort studies with participants confirmed by laboratory test for dengue infection and comparison among the different severity of dengue infection by using statistical models. The methodological quality of the paper was assessed by independent reviewers using QUADAS ‐2. Results Twenty‐six studies published from 1994 to 2017 were included. Most diagnostic models produced an accuracy of 75% to 80% except one with 86%. Two models predicting severe dengue according to the WHO 2009 classification have 86% accuracy. Both of these logistic regression models were applied during the first three days of illness, and their sensitivity and specificity were 91–100% and 79.3–86%, respectively. Another model which evaluated the 30‐day mortality of dengue infection had an accuracy of 98.5%. Conclusion Although there are several potential predictive or diagnostic models for dengue infection, their limitations could affect their validity. It is recommended that these models be revalidated in other clinical settings and their methods be improved and standardised in future.
收起
摘要 :
ELISAs and rapid diagnostic tests (RDTs) are widely used for diagnosing dengue virus (DENV) infection. Using 138 single blood samples, we compared the ability to detect non-structural (NS)-1 antigen and anti-DENV IgM/IgG antibodie...
展开
ELISAs and rapid diagnostic tests (RDTs) are widely used for diagnosing dengue virus (DENV) infection. Using 138 single blood samples, we compared the ability to detect non-structural (NS)-1 antigen and anti-DENV IgM/IgG antibodies among (1) DENV Detect NS1 ELISA, DENV Detect IgM capture ELISA and DENV Detect IgG ELISA (InBios International, Inc.); (2) Anti-Dengue virus IgM Human ELISA and Anti-Dengue virus IgG Human ELISA (Abcam); (3) Dengue virus NS1 ELISA, Anti-Dengue virus ELISA (IgM) and Anti-Dengue virus ELISA (IgG) (Euroimmun); (4) Asan Easy Test Dengue NS1 Ag 100 and Asan Easy Test Dengue IgG/IgM (Asan Pharm); (5) SD BIOLINE Dengue Duo (Standard Diagnostics); and (6) Ichroma Dengue NS1 and Ichroma Dengue IgG/IgM (Boditech Med). For NS1 antigen detection, InBios and Euroimmun showed higher sensitivities (100%) than the RDTs (42.9–64.3%). All tests demonstrated variable sensitivities for IgM (38.1–90.5%) and IgG (65.7–100.0%). InBios and Boditech Med demonstrated higher sensitivity (95.6% and 88.2%, respectively) than the other tests for combined NS1 antigen and IgM antibody. Five NS1 antigen tests had good agreement (92.8–98.6%) without showing positivity for chikungunya. However, all IgG tests demonstrated potential false-positivity with variable ranges. Clinical laboratories should note performance variations across tests and potential cross-reactivity.
收起
摘要 :
Increasing numbers of dengue fever (DF) cases reflect the increasing travel mobility together with the expanding geographical distribution of the vector Aedes aegypti. Compared with earlier surveys in Germany, higher incidences oc...
展开
Increasing numbers of dengue fever (DF) cases reflect the increasing travel mobility together with the expanding geographical distribution of the vector Aedes aegypti. Compared with earlier surveys in Germany, higher incidences occur and correlate well with ongoing outbreaks. Therefore, we investigated 767 serum samples from 594 returning travellers with suspected DF between 2005 and 2010, which where sent from different hospitals in the drainage area Frankfurt/Main. Established diagnostic assays were ELISA, immunofluorescence and chromatographic tests. We obtained 112 dengue-seropositive serum samples from totally 60 patients: the detection rate was 10.1% (60 out of 594). A significant increase was found in 2010. Most patients were aged between 40 and 49, and indirect immunofluorescence technique indicated mainly DF serotype 2. Actual data reveal a significant rise in imported DF cases in 2010 according to an increasing risk to acquire DF virus infection. Nevertheless, dengue haemorrhagic fever and dengue shock syndrome are still rare in travellers, but those with a history of dengue should be tested for DF serotypes and advised to protect themselves well from mosquitoes when travelling to endemic areas.
收起
摘要 :
Background: The measurement and detection of viremia and antigenemia in sera have been used as a marker of risk for dengue disease severity and diagnosis. However, evidence exists suggesting that levels of viremia and antigenemia ...
展开
Background: The measurement and detection of viremia and antigenemia in sera have been used as a marker of risk for dengue disease severity and diagnosis. However, evidence exists suggesting that levels of viremia and antigenemia are affected by the presence of specific antibodies. Objective: To compare viral load and circulating NS1 levels in sera from patients positive or negative for dengue specific IgM antibodies. Study design: Three hundred and eighty serum samples were analyzed for viral load using qRT-PCR and for levels of circulating NS1 and the presence of specific antibodies using commercial EIAs. Results and conclusion: Comparison of viremia levels in sera from patients positive or negative for dengue IgM antibodies showed that viral load was significantly higher ( p≤. 0.0001) in patients negative for IgM antibodies. In contrast, levels of circulating NS1 were found unaffected by the presence of IgM ( p= 0.0038). Thus, dengue virus specific IgM antibodies in sera seem to be a strong negative modulator of viremia levels in patient's sera.
收起
原文获取