Host Genetic Polymorphisms Influencing Susceptibility to Dengue

Unveiling the Dual Threat: Myocarditis in the Spectrum of Dengue Fever

This meta-analysis aims to systematically review and analyze available studies on the association between myocarditis and dengue viral fever. A comprehensive literature search was carried out using several databases. Mantel-Haenszel odds ratios and associated 95% confidence intervals were produced to report the overall effect size using random effect models. Besides, random effects models were used to calculate the overall pooled prevalence. Data from 26 articles (6622 dengue patients) showed that pooled estimate of myocarditis in dengue fever was 12.4% (95% CI, 8.41-17.08). Higher prevalence was seen in reports from Asia (15.2%) compared to that from Latin America (3.6%). Besides, the pooled prevalence of severity and mortality was 34% (95% CI, 20.49-49.04) and 26.44% (95% CI, 18.07-35.78) respectively. Significantly higher prevalence rates of severe disease in the pediatric population (52.4%) and studies with a higher percentage of females (52.1%) were also observed. However, higher mortality rates were seen in the adult population (34.8%) compared with the pediatric age group. Further, myocarditis in dengue patients was associated with increased risk of severity (RR = 2.44, 95% CI 1.007-5.93, P = 0.048) and mortality (RR = 19.41, 95% CI 7.19-52.38, P < 0.001) compared with dengue patients without myocarditis. No significant publication bias was evident in the meta-analysis. The findings highlight the clinical significance of early identification and management of myocarditis in patients with dengue fever.

Association of dengue virus non-structural-1 protein with disease severity: a brief review

Dengue virus (DENV) was discovered by P. M. Ashburn and Charles F. Craig in 1907. Evidence of dengue-like illness was observed before 1907 and DENV epidemics have been reported from different parts of the world since then, with increased morbidity rates every year. DENV typically causes a febrile illness that ranges from mild asymptomatic infection to fatal dengue haemorrhagic fever (DHF) and/or dengue shock syndrome (DSS). Host mechanisms through which mild infection progresses to the fatal forms are still unknown. Few factors have been associated to aid severe disease acquisition, DENV non-structural 1 (NS1) protein being one of them. NS1 is a highly conserved glycoprotein among the Flavivirus and is often used as a biomarker for dengue diagnosis. This review focuses on assessing the role of NS1 in severe dengue. In this review, hospital-based studies on the association of dengue NS1 with severe dengue from all over the world have been assessed and analysed and the majority of the studies positively correlate high NS1 levels with DHF/DSS acquisition. The review also discusses a few experimental studies on NS1 that have shown it contributes to dengue pathogenesis. This review assesses the role of NS1 and disease severity from hospital-based studies and aims to provide better insights on the kinetics and dynamics of DENV infection with respect to NS1 for a better understanding of the role of NS1 in dengue.

What is the association between the IL6-174 G > C (rs1800795) polymorphism and the risk of dengue? Evidence from a meta-analysis

The association of polymorphisms in genes responsible for immunological mediators with dengue allows the identification of certain genetic alterations that increase or decrease the development risk of the disease. A few number of studies that correlate the interleukin 6-174 G > C (IL6-174 G > C) polymorphism (rs1800795) with dengue. However, there is an inconsistency on the polymorphism influence on the disease which motivated this meta-analysis. So, this study aimed to evaluate the rs1800795 polymorphism with protection or susceptibility for development of dengue. A search of the literature was performed for studies published before 05 September 2020 in various databases. Calculations of Odds Ratio (OR) with 95% of Confidence Intervals (CI) and heterogeneity (I²) were assessed and publication bias was done by Begg' and Egger's test. The value of P < 0.05 was considered as significant. As results, five case-control studies were identified and included in the results. The analysis showed that the heterozygous genotype has a protective role against dengue without warning signs (DWOS) (OR = 0.57, p = 0.001), as well as the polymorphic C allele (OR = 0.77, p = 0.04). When unifying the data from the included studies, the GG genotype was more prevalent among individuals with dengue with warning signs (DWWS) when compared to the control group (p = 0.0221). GC genotype was more prevalent in the control group than in the DWWS group (p = 0.0119). Therefore, in our study we observed that the GC genotype and the C allele have a protective role against DWOS. Since this polymorphism is associated with low IL-6 expression, thus it is expected that there will be a decreased pro-inflammatory response. However, more studies regarding this thematic are necessary to have a consensus about this polymorphism and dengue.