ABSTRACT
ABSTRACT We conducted a spatial case-control study nested in a dengue incidence cohort to explore the role of the spatial and socioeconomic factors in the proportion of symptomatic (cases) and inapparent primary dengue virus infections (controls). Cohort participants were children and adolescents (2 to 16 years of age) at the beginning of the follow-up. Case definitions were, for symptomatic cases, fever plus a positive lab result for acute dengue (NS1, RT-PCR, ELISA IgM/IgG), and for inapparent infection a positive result for dengue IgG (ELISA) in subjects without symptoms and with a previously negative result at baseline. The covariates included sociodemographic factors, residential location, and socioeconomic context variables of the census tracts of residence of cases and controls. We used principal component analysis to reduce the contextual covariates, with the component values assigned to each one based on their residences. The data were modeled in a Bayesian context, considering the spatial dependence. The final sample consisted of 692 children, 274 cases and 418 controls, from the first year of follow-up (2014-2015). Being male, older age, higher educational level of the head of the family and having a larger number of rooms in the household were associated with a greater chance of presenting dengue symptomatic infection at the individual level. The contextual covariates were not associated with the outcome. Inapparent dengue infection has extensive epidemiological consequences. Relying solely on notifications of symptomatic dengue infections underestimates the number of cases, preserves a silent source of the disease, potentially spreading the virus to unaffected areas.
ABSTRACT
Dengue virus (DENV) infection is a significant burden in Indonesia and other tropical countries. DENV infection have wide spectrum of clinical manifestations i.e. asymptomatic, dengue fever, dengue hemorrhagic fever and dengue shock syndrome. The difference of clinical manifestation may due to the deversity of genetic constitution of the host. The C-type lectin DC-SIGN (CD209) has been identified to be the major dengue receptor on human dendritic cells. There are at least five polymorphisms in exon 5 and 6 of DC-SIGN encoded gene which have been identified and recorded in dbSNP. The aim of this work is to measure the frequency of these polymorphisms among asymptomatic and hospitalized DENV infected patients. We enrolled 23 hospitalized and 73 asymptomatic DENV infected patients. Among those subject we performed PCR amplification and DNA direct seqencing for 23 hospitalized DENV infected patients and 24 asymptomatic DENV infected patients. The result showed that there were no polymorphic nucleotides in CD209 encoded gene found among the patients.
ABSTRACT
Dengue virus (DENV) infection is a significant burden in Indonesia and other tropical countries. DENV infection has a wide spectrum of clinical manifestations, i.e. asymptomatic, dengue fever, dengue hemorrhagic fever and dengue shock syndrome. The variety of clinical manifestations may be due to the diversity of genetic constitution of the host. The C-type lectin DC-SIGN (CD209) has been identified as the major dengue receptor on human dendritic cells. There are at least five polymorphisms in exon 5 and 6 of the DC-SIGN encoded gene which have been identified and recorded in dbSNP. The aim of this work is to measure the frequency of these polymorphisms among asymptomatic and hospitalized DENV-infected patients. We enrolled 23 hospitalized and 73 asymptomatic DENV-infected patients. Among the subjects, we performed PCR amplification and DNA direct seqencing for 23 hospitalized DENV-infected patients and 24 asymptomatic DENV-infected patients. The result showed that there were no polymorphic nucleotides in the CD209 encoded gene among the patients.
ABSTRACT
Background & objectives: Dengue virus (DV) infection has emerged as a major health problem in north India. Here, we report the annual trend of dengue virus infection as seen in Lucknow, Uttar Pradesh, during 2008-2010. Methods: Blood samples from clinically suspected cases of dengue virus infection were collected and history was taken on structured clinical data sheet. All samples were tested for dengue IgM by antibody capture ELISA. Selected samples were tested by conventional RT-PCR for dengue virus RNA. Weather information was continuously recorded from website of world weather information service. Results: There was a gradual increase in number of dengue fever cases with increased occurrence in 2010. Cases referred in January - December 2008 were 398 (54.5% anti DV IgM positive), in January - December 2009 were 599 (51.9% anti DV IgM positive) and in January - December 2010 were 1602 (64.9% anti DV IgM positive). Serotypes circulating in years 2008, 2009 and 2010 were DV-2 & DV-3, DV -1, 2 & 3 and DV-1 and DV-2 respectively. There is no statistical significant correlation between weather data and increasing dengue positive cases. Interpretation & conclusions: Increased cases of dengue fever were seen in 2010, which was not correlated with any change in environmental factors. A change in circulating serotypes was noted.