Dengue virus

About: Dengue virus is a research topic. Over the lifetime, 12671 publications have been published within this topic receiving 461406 citations. The topic is also known as: DENV.

Enzyme-Linked Immunosorbent Assay Specific to Dengue Virus Type 1 Nonstructural Protein NS1 Reveals Circulation of the Antigen in the Blood during the Acute Phase of Disease in Patients Experiencing Primary or Secondary Infections

Abstract: During flavivirus infection in vitro, nonstructural protein NS1 is released in a host-restricted fashion from infected mammalian cells but not vector-derived insect cells. In order to analyze the biological relevance of NS1 secretion in vivo, we developed a sensitive enzyme-linked immunosorbent assay (ELISA) to detect the protein in the sera of dengue virus-infected patients. The assay was based on serotype 1 NS1-specific mouse and rabbit polyclonal antibody preparations for antigen immunocapture and detection, respectively. With purified dengue virus type 1 NS1 as a protein standard, the sensitivity of our capture ELISA was less than 1 ng/ml. When a panel of patient sera was analyzed, the NS1 antigen was found circulating from the first day after the onset of fever up to day 9, once the clinical phase of the disease is over. The NS1 protein could be detected even when viral RNA was negative in reverse transcriptase-PCR or in the presence of immunoglobulin M antibodies. NS1 circulation levels varied among individuals during the course of the disease, ranging from several nanograms per milliliter to several micrograms per milliliter, and peaked in one case at 50 μg/ml of serum. Interestingly, NS1 concentrations did not differ significantly in serum specimens obtained from patients experiencing primary or secondary dengue virus infections. These findings indicate that NS1 protein detection may allow early diagnosis of infection. Furthermore, NS1 circulation in the bloodstream of patients during the clinical phase of the disease suggests a contribution of the nonstructural protein to dengue virus pathogenesis.

Evidence that maternal dengue antibodies are important in the development of dengue hemorrhagic fever in infants.

Abstract: To establish the role of maternal dengue-specific antibodies in the development of dengue hemorrhagic fever and dengue shock syndrome caused by dengue 2 virus in infants, we examined sera from mothers of infants and toddlers with dengue hemorrhagic fever or dengue shock syndrome and mothers of infants with pyrexia of unknown origin. The mean titers of hemagglutination inhibition, neutralization, and infection-enhancing activities against dengue 2 virus were not statistically different among the three groups. However, among infants who developed dengue hemorrhagic fever/dengue shock syndrome there was a strong correlation between the mothers' dengue 2 neutralizing titers and infant age at the time of onset of severe illness, where no such correlation was found among the other two groups. Furthermore, the actual age at which dengue hemorrhagic fever/dengue shock syndrome occurred in each infant correlated with the age at which maximum enhancing activity for dengue 2 infection in mononuclear phagocytes was predicted. This critical time for the occurrence of dengue hemorrhagic fever/dengue shock syndrome was observed to be approximately 2 months after the time calculated for maternal dengue 2 neutralizing antibodies to degrade below a protective level. In addition, sera of mothers of infants with dengue hemorrhagic fever/dengue shock syndrome enhanced dengue 2 virus infection to a slightly greater degree than did sera from mothers of infants with pyrexia of unknown origin and toddlers with dengue hemorrhagic fever/dengue shock syndrome. These data are consistent with the hypothesis that maternal dengue antibodies play a dual role by first protecting and later increasing the risk of development of dengue hemorrhagic fever/dengue shock syndrome in infants who become infected by dengue 2 virus.

Dengue viral infections

Abstract: Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing this disease. Early recognition and prompt initiation of appropriate treatment are vital if disease related morbidity and mortality are to be limited. This review outlines aspects of the epidemiology of dengue infections, the dengue virus and its mosquito vector, clinical features and pathogenesis of dengue infections, and the management and control of these infections.

Monoclonal Antibodies That Bind to Domain III of Dengue Virus E Glycoprotein Are the Most Efficient Blockers of Virus Adsorption to Vero Cells

Abstract: The specific mechanisms by which antibodies neutralize flavivirus infectivity are not completely understood. To study these mechanisms in more detail, we analyzed the ability of a well-defined set of anti-dengue (DEN) virus E-glycoprotein-specific monoclonal antibodies (MAbs) to block virus adsorption to Vero cells. In contrast to previous studies, the binding sites of these MAbs were localized to one of three structural domains (I, II, and III) in the E glycoprotein. The results indicate that most MAbs that neutralize virus infectivity do so, at least in part, by the blocking of virus adsorption. However, MAbs specific for domain III were the strongest blockers of virus adsorption. These results extend our understanding of the structure-function relationships in the E glycoprotein of DEN virus and provide the first direct evidence that domain III encodes the primary flavivirus receptor-binding motif.