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.

Impact of prior flavivirus immunity on Zika virus infection in rhesus macaques.

Abstract: Studies have demonstrated cross-reactivity of anti-dengue virus (DENV) antibodies in human sera against Zika virus (ZIKV), promoting increased ZIKV infection in vitro. However, the correlation between in vitro and in vivo findings is not well characterized. Thus, we evaluated the impact of heterotypic flavivirus immunity on ZIKV titers in biofluids of rhesus macaques. Animals previously infected (≥420 days) with DENV2, DENV4, or yellow fever virus were compared to flavivirus-naive animals following infection with a Brazilian ZIKV strain. Sera from DENV-immune macaques demonstrated cross-reactivity with ZIKV by antibody-binding and neutralization assays prior to ZIKV infection, and promoted increased ZIKV infection in cell culture assays. Despite these findings, no significant differences between flavivirus-naive and immune animals were observed in viral titers, neutralizing antibody levels, or immune cell kinetics following ZIKV infection. These results indicate that prior infection with heterologous flaviviruses neither conferred protection nor increased observed ZIKV titers in this non-human primate ZIKV infection model.

Wolbachia Reduces the Transmission Potential of Dengue-Infected Aedes Aegypti

Abstract: Background Dengue viruses (DENV) are the causative agents of dengue, the world's most prevalent arthropod-borne disease with around 40% of the world's population at risk of infection annually. Wolbachia pipientis, an obligate intracellular bacterium, is being developed as a bio-control strategy against dengue because it limits replication of the virus in the mosquito. The Wolbachia strain wMel, which has been introduced into the mosquito vector, Aedes aegypti, has been shown to invade and spread to near fixation in field releases. Standard measures of Wolbachia's efficacy for blocking virus replication focus on the detection and quantification of virus in mosquito tissues. Examining the saliva provides a more accurate measure of transmission potential and can reveal the extrinsic incubation period (EIP), that is, the time it takes virus to arrive in the saliva following the consumption of DENV viremic blood. EIP is a key determinant of a mosquito's ability to transmit DENVs, as the earlier the virus appears in the saliva the more opportunities the mosquito will have to infect humans on subsequent bites.

Current challenges and implications for dengue, chikungunya and Zika seroprevalence studies worldwide: A scoping review.

Abstract: Background Arboviral infections are a public health concern and an escalating problem worldwide. Estimating the burden of these diseases represents a major challenge that is complicated by the large number of unapparent infections, especially those of dengue fever. Serological surveys are thus required to identify the distribution of these diseases and measure their impact. Therefore, we undertook a scoping review of the literature to describe and summarize epidemiological practices, findings and insights related to seroprevalence studies of dengue, chikungunya and Zika virus, which have rapidly expanded across the globe in recent years. Methodology/Principal findings Relevant studies were retrieved through a literature search of MEDLINE, WHOLIS, Lilacs, SciELO and Scopus (2000 to 2018). In total, 1389 publications were identified. Studies addressing the seroprevalence of dengue, chikungunya and/or Zika written in English or French and meeting the inclusion and exclusion criteria were included. In total, 147 studies were included, from which 185 data points were retrieved, as some studies used several different samples. Most of the studies were exclusively conducted on dengue (66.5%), but 16% were exclusively conducted on chikungunya, and 7 were exclusively conducted on Zika; the remainder were conducted on multiple arboviruses. A wide range of designs were applied, but most studies were conducted in the general population (39%) and in households (41%). Although several assays were used, enzyme-linked immunosorbent assays (ELISAs) were the predominant test used (77%). The temporal distribution of chikungunya studies followed the virus during its rapid expansion since 2004. The results revealed heterogeneity of arboviruses seroprevalence between continents and within a given country for dengue, chikungunya and Zika viruses, ranging from 0 to 100%, 76% and 73% respectively. Conclusions/Significance Serological surveys provide the most direct measurement for defining the immunity landscape for infectious diseases, but the methodology remains difficult to implement. Overall, dengue, chikungunya and Zika serosurveys followed the expansion of these arboviruses, but there remain gaps in their geographic distribution. This review addresses the challenges for researchers regarding study design biases. Moreover, the development of reliable, rapid and affordable diagnosis tools represents a significant issue concerning the ability of seroprevalence surveys to differentiate infections when multiple viruses co-circulate.

Identification of an epitope on the dengue virus membrane (M) protein defined by cross-protective monoclonal antibodies: design of an improved epitope sequence based on common determinants present in both envelope (E and M) proteins

Abstract: The protective capacity of monoclonal antibodies (MAbs) generated to the dengue-2 virus envelope (E) and premembrane (prM) proteins was tested in vivo. Two anti-E MAbs, 2C5.1 and 4G2 and two anti-prM MAbs, 2A4.1 and 2H2 provided cross-protection against all four dengue virus serotypes. Overlapping sets of synthetic peptides spanning amino-acid sequence 301–401 (domain III) of the E protein and the entire prM protein were then used to locate their epitopes. The anti-E MAbs strongly reacted with the peptide sequence 349-GRLITVNPIVT-359 (E349–359) from domain III and the immunodominant epitope, 274-SGNLLFTGHL-283 (E274–283) from the hinge region between domains I and II. The anti-prM MAbs strongly reacted with the sequence, 40-PGFTVMAAIL-49 (M40–49) from the first membrane-spanning domain of the M protein. These anti-prM MAbs also reacted with peptides E274–283 and E349–359, while the anti-E MAbs reacted with a peptide sequence, 1-FHLTTRNGEP-10 from the prM protein and these cross-reactions with both proteins were confirmed using immunoblot assays. MAbs 2C5.1, 4G2 and 2H2 more strongly reacted with an MEH1 peptide GLFTPNLITI, which was designed as an antigenic hybrid between these E and prM peptide sequences, than with any of these natural peptide sequences. These peptide sequence will now be tested for their ability to generate cross-protective antibodies against each dengue virus serotype when delivered with appropriate T-helper epitopes.