Secondary dengue infection in schoolchildren in a dengue endemic area in the State of Rio de Janeiro, Brazil

Cunha, Rivaldo Venâncio da; Dias, Márcio; Nogueira, Rita Maria Ribeiro; Chagas, Nelson; Miagostovich, Marize Pereira; Schtzmayr, Hermann G.

doi:10.1590/s0036-46651995000600008

Cited by 25 publications

(19 citation statements)

References 10 publications

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“…This might represent a major risk factor for secondary DENV infections and more severe diseases, such as dengue haemorrhagic fever, if a new dengue serotype to which there has been limited prior exposure should suddenly be introduced. For instance, in a study of children at public schools in Rio de Janeiro, Brazil, Chunha et al [44, 45] observed secondary infections among 61% of positive cases; noticeably, 75% of them were in patients under 15 years of age.…”

Section: Discussionmentioning

confidence: 99%

Dengue seroprevalence, seroconversion and risk factors in Dhaka, Bangladesh

Dhar-Chowdhury¹,

Paul²,

Haque³

et al. 2017

PLoS Negl Trop Dis

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BackgroundDengue virus (DENV) activity has been reported in Dhaka, Bangladesh since the early 1960s with the greatest burden of dengue fever and dengue hemorrhagic fever cases observed in 2000. Since this time, the intensity of dengue activity has varied from year to year, and its determining factors remained relatively unknown. In light of such gaps in knowledge, the main objectives of this study were to determine the magnitude of seroprevalence and seroconversion among the surveyed population, and establish the individual/household level risk factors for the presence of DENV antibodies among all age groups of target populations in the city of Dhaka.Methodology/Principal findingsConsidering the lack of fine scale investigations on the factors driving dengue activity in Bangladesh, a prospective cohort study involving serological surveys was undertaken with participant interviews and blood donation across the city of Dhaka in 2012. Study participants were recruited from 12 of 90 wards and blood samples were collected during both the pre-monsoon (n = 1125) and post-monsoon (n = 600) seasons of 2012. The findings revealed that the seroprevalence in all pre-monsoon samples was 80.0% (900/1125) while the seropositivity in the pre-monsoon samples that had paired post-monsoon samples was 83.3% (503/600). Of the 97 paired samples that were negative at the pre-monsoon time point, 56 were positive at the post-monsoon time point. This resulted in a seroprevalence of 93.2% (559/600) among individuals tested during the post-monsoon period. Seroprevalence trended higher with age with children exhibiting a lower seropositivity as compared to adults. Results from this study also indicated that DENV strains were the only flaviviruses circulating in Dhaka in 2012. A multivariate analysis revealed that age, possession of indoor potted plants, and types of mosquito control measures were significant factors associated with DENV seroprevalence; while attendance in public/mass gatherings, and use of mosquito control measures were significantly associated with DENV seroconversion after adjusting for all other variables.Conclusions/SignificanceOur study suggests that there is a high level of endemic dengue virus circulation in the city of Dhaka which has resulted in significant DENV seroprevalence among its residents. Seropositivity increased with age, however, a substantial proportion of children are at risk for DENV infections. Our serological analysis also documents considerable DENV seroconversion among study participants which indicates that a large proportion of the population in the city of Dhaka were newly exposed to DENV during the study period (pre-and post-monsoon 2012). High levels of seroconversion suggest that there was an intense circulation of DENV in 2012 and this may have resulted in a significant risk for viral associated illness. Findings of our study further indicated that home-based interventions, such as removing indoor potted plants and increased bed net use, in addition to vector control measures in public parks...

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Section: Discussionmentioning

confidence: 99%

Dengue seroprevalence, seroconversion and risk factors in Dhaka, Bangladesh

Dhar-Chowdhury¹,

Paul²,

Haque³

et al. 2017

PLoS Negl Trop Dis

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“…For instance, the state of Rio de Janeiro is considered an endemic area for dengue virus infection. 19 Some authors emphasized the importance to evaluate the analytical specificity of the test, as also recommended by FDA. 20,21 By our evaluation, no significant difference inferred by Pearson's correlation coefficient (p D 0.9950) was observed between the Ct values generated by distinct concen- trations of plasmid containing the NS5 region of 17DD-YFV, diluted in negative human serum and in serum containing together Mumps virus, Dengue 1, 2 and 3 and Measles (Fig.…”

Section: Discussionmentioning

confidence: 99%

New approaches for the standardization and validation of a real-time qPCR assay using TaqMan probes for quantification of yellow fever virus on clinical samples with high quality parameters

Fernandes-Monteiro

Trindade

Yamamura

et al. 2015

Human Vaccines & Immunotherapeutics

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Abbreviation: PCR, polymerase chain reaction; RT-qPCR, reverse transcriptase quantitative polymerase chain reaction; YFV, yellow fever virus; NS5, protein of the viral polyprotein, it is the largest and the most highly conserved among the flaviviral proteins; 17DD, strain used to yellow fever vaccine; YF, yellow fever; RNA, ribonucleic acid; C, capsid protein; prM/M, membrane protein; E, envelope protein; NS, nonstructural protein; ELISA, enzyme-linked immunosorbent assay; DNA, deoxyribonucleic acid; DL, detection limit; QL, quantification limit; ANVISA, Brazilian Health Surveillance Agency; CV, coefficient of variation; RNAse P, human constitutive gene; Ct, cycle threshold; EXO IPC, exogenous internal positive control; PFU, plaque former unit; FDA, food and drug administration agency; JEV, japanese encephalitis virus; DENV, dengue virus; MuV, mumps virus; MV, measles virus; MOI, multiplicity of infection; WNV, West Nile VirusThe development and production of viral vaccines, in general, involve several steps that need the monitoring of viral load throughout the entire process. Applying a 2-step quantitative reverse transcription real time PCR assay (RT-qPCR), viral load can be measured and monitored in a few hours. In this context, the development, standardization and validation of a RT-qPCR test to quickly and efficiently quantify yellow fever virus (YFV) in all stages of vaccine production are extremely important. To serve this purpose we used a plasmid construction containing the NS5 region from 17DD YFV to generate the standard curve and to evaluate parameters such as linearity, precision and specificity against other flavivirus. Furthermore, we defined the limits of detection as 25 copies/reaction, and quantification as 100 copies/reaction for the test. To ensure the quality of the method, reference controls were established in order to avoid false negative results. The qRT-PCR technique based on the use of TaqMan probes herein standardized proved to be effective for determining yellow fever viral load both in vivo and in vitro, thus becoming a very important tool to assure the quality control for vaccine production and evaluation of viremia after vaccination or YF disease.

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“…Epidemiological impact assessments of these interventions have shown that their effectiveness is extremely limited 20,23 . Regardless of each local health system's operational and administrative difficulties, even when these measures are well managed, their effectiveness is always low, given the intense viral circulation detected in the successive epidemics and the results of serological surveys conducted in various Brazilian cities 6,20,21,22,23,54 . Number of hospitalizations for dengue hemorrhagic fever, according to age group.…”

Section: Limits and Challenges For Dengue Controlmentioning

confidence: 99%

“…Even where programs to combat the vector have been well structured and the infestation rates have been maintained relatively low, as in Singapore and Cuba 38,55 , the dengue virus has circulated with great intensity. This phenomenon is a function of favorable environmental conditions for proliferation and survival of this mosquito between latitude 35º North and 35º South and the transmission force of the dengue virus in the presence of a large number of susceptible individuals 38,54,56 .…”

Section: Limits and Challenges For Dengue Controlmentioning

confidence: 99%