Dengue virus serotypes and related factors in children with dengue hemorrhagic fever in Southern Vietnam.

INTRODUCTION: After the Coronavirus Disease 2019 pandemic, a high number of cases and severe dengue in children were reported in some provinces in the south of Vietnam. This study aimed to determine the distribution of dengue virus serotypes and their correlation with demographic factors, disease severity, clinical manifestations, and laboratory findings. METHODOLOGY: This study employed a cross-sectional design. Ninety-six dengue-infected children admitted to Can Tho Children's Hospital between October 2022 and March 2023 were included. Confirmation of dengue infection was achieved through the real-time polymerase chain reaction (RT-PCR). RESULTS: Among the identified serotypes, DENV-2 accounted for the highest proportion (71.87%), followed by DENV-1 (23.96%), and DENV-4 (4.17%). DENV-3 was not detected. No significant demographic, disease severity, or laboratory differences were observed among the identified dengue serotypes. However, DENV-2 was associated with a higher occurrence of mucous membrane hemorrhages and gastrointestinal bleeding compared to other serotypes. CONCLUSIONS: Although DENV-2 was the most prevalent serotype responsible for dengue in children in southern Vietnam, it did not lead to more severe cases compared to other serotypes. This finding is crucial for evaluating the illness's prognosis.

Analysis of signs and symptoms in confirmed cases of severe dengue among children aged 0 to 10 years old.

OBJECTIVE: The prevalent symptoms of severe dengue in pediatric patients are divided into three subgroups: severe plasma leakage, severe bleeding, and severe organ damage. In addition, the seasonal patterns of the disease and the outcomes of cure or death from dengue were evaluated. METHODS: An epidemiological, observational, analytical, cross-sectional study was conducted with data from the Notifiable Disease Information System (SINAN - Sistema de Informação de Agravos de Notificação and DATASUS - Departamento de Informática do Sistema Único de Saúde) of the Ministry of Health from 2019 to 2020. RESULTS: During the study period, 1,857 cases of severe dengue were observed in the pediatric age group, with the most common symptoms being respiratory failure, melena, hematemesis, and altered level of consciousness. The total proportion of patients hospitalized for severe dengue was 89.6%, and 51.2% of these patients died, corroborating the importance of early detection of the disease. CONCLUSION: Severe dengue is more prevalent during the seasonal period, with hot and humid characteristics owing to the mechanism involved in the viral cycle. The most prevalent symptoms of severe dengue in pediatric patients were respiratory failure alone, gastrointestinal bleeding, and altered level of consciousness. It is important to identify signs of severity for early intervention and a better prognosis, considering that death is closely related to a delayed diagnosis.

Retrospective Analysis of Severe Dengue by Dengue Virus Serotypes in a Population with Social Security, Mexico 2023.

BACKGROUND: Risk factors for severe dengue manifestations have been attributed to various factors, including specific serotypes, sex, and age. Mexico has seen the re-emergence of DENV-3, which has not circulated in a decade. OBJECTIVE: To describe dengue serotypes by age, sex, and their association with disease severity in dengue-positive serum samples from epidemiological surveillance system units. MATERIALS AND METHODS: A descriptive analysis was conducted to evaluate the frequency of dengue severity by sex, age, disease quarter, geographical location, and dengue virus serotypes. The study was conducted using laboratory samples from confirmed dengue cases through RT-qPCR from the epidemiological surveillance laboratory network of the Mexican Social Security Institute, Mexico. Simple frequencies and proportions were calculated using the z-test for proportional differences between groups. Bivariate analysis with adjusted Chi2 was performed, and binary logistic regression models were constructed using the forward Wald method considering the model's predictive capacity. The measure of association was the odds ratio, with 95% confidence intervals. Statistical significance was set to an alpha level of <0.05. RESULTS: In 2023, 10,441 samples were processed for dengue RT-qPCR at the IMSS, with a predominance of serotype DENV-3 (64.4%). The samples were mostly from women (52.0%) and outpatient cases (63.3%). The distribution of dengue severity showed significant variations by age, with a lower proportion of severe cases in young children and a higher proportion in the 5- to 14-year-old group. Hospitalizations increased significantly with severity. Warm regions had more cases overall and severity. Cases were most frequent from July to September. While DENV-2 was associated with severity, DENV-4 was not. Binary regression identified higher risk in women, age extremes, and DENV-2, with an overall predictive model of 58.5%. CONCLUSIONS: Women, age groups at the extremes of life, and the DENV-2 serotype presented severe risk of dengue in a population with social security in Mexico during 2023.

Cytokine profiles in dengue fever and dengue hemorrhagic fever: A study from Indonesia.

Recent studies have demonstrated that cytokine dysregulation has a critical role in the pathogenesis of dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). The aim of this study was to investigate the association between tumor necrosis factor (TNF- α), interleukin 6 (IL-6), interleukin 10 (IL-10), and interleukin 17 (IL-17) with infection status, and severity of dengue. A prospective cross-sectional study was conducted at three hospitals in Gianyar regency and Denpasar municipality, Bali, Indonesia, from June to December 2022. Sixty-four dengue infected patients were involved. Patients' serum was tested for dengue infection using NS1 antigen rapid test, dengue virus immunoglobulin M (IgM) and immunoglobulin G (IgG) test, and reverse transcription polymerase chain reaction (RT-PCR). Cytokine levels (TNF-α, IL-6, IL-10, and IL-17) were measured using enzyme-linked immunosorbent assay (ELISA). Infection status was determined by combining serological and RT-PCR results, categorizing patients into primary and secondary infections. The present study found that DF patients had lower TNF-α, IL-6, and IL-17 but higher IL-10 levels compared to DHF patients (p<0.001). Elevated TNF-α, IL-6, and IL-17 levels were higher in secondary infection, while IL-10 level was higher in primary infection (p<0.001). In conclusion, cytokines play a crucial role in the interplay between cytokine dysregulation and dengue infection dynamics.

Evaluation of clinical and laboratory characteristics of dengue viral infection and risk factors of dengue hemorrhagic fever: a multi-center retrospective analysis.

BACKGROUND: Dengue Viral Infection (DVI) has become endemic in Pakistan since the first major outbreak in Karachi in 1996. Despite aggressive measures taken by relevant authorities, Pakistan has been dealing with a worsening dengue crisis for the past two decades. DHF is severe form of dengue infection which is linked with significant morbidity and mortality. Early identification of severe dengue infections can reduce the morbidity and mortality. In this context we planned current study in which we find out the different factors related with DHF as well as clinical laboratory features of DHF and compare them to DF so that patients can be best evaluated for DHF and managed accordingly at admission. METHODS: Retrospective study conducted over a period of 6 years (2013-2018) in two tertiary care hospitals in Pakistan. Data were collected by using a pre-structured data collection form. Data were statistically analyzed to determine the clinical and laboratory characteristics of DVI and risk factors of dengue hemorrhagic fever (DHF). RESULTS: A total 512 dengue cases (34.05 ± 15.08 years; Male 69.53%) were reviewed. Most common clinical manifestations of DVI were fever (99.60%), headache (89.1%), chills (86.5%), rigors (86.5%), myalgia (72.3%). Less common clinical manifestations were vomiting (52.5%), arthralgia (50.2%) and skin rashes (47.5%). Furthermore, nasal bleeding (44.1%), gum bleeding (32.6%), pleural effusion (13.9%) and hematuria (13.1%) were more profound clinical presentations among DHF patients. Mortality rate was 1.5% in this study. Logistic regression analysis indicated that delayed hospitalization (OR: 2.30) and diabetes mellitus (OR:2.71), shortness of breath (OR:2.21), association with risk groups i.e., living near stagnant water, travelling to endemic areas, living in endemic regions (OR:1.95), and presence of warning signs (OR:2.18) were identified as risk factors of DHF. Statistically we found that there is strong association of diabetes mellitus (DM) with DHF while the patient suffering from DM individually had higher odds (2.71) of developing DHF than patients without disease. CONCLUSIONS: The current study demonstrated that the clinical and laboratory profiles of DF and DHF are significantly distinct. Significant predictors of DHF were advanced age, diabetes mellitus, ascites, pleural effusion, thick gallbladder and delayed hospitalization. The identification of these factors at early stage provides opportunities for the clinicians to identify high risk patients and to reduce dengue-related morbidity and mortality.

Genotype of dengue virus serotype 1 in relation to severe dengue in Guangzhou, China.

Guangzhou has been the city most affected by the dengue virus (DENV) in China, with a predominance of DENV serotype 1 (DENV-1). Viral factors such as dengue serotype and genotype are associated with severe dengue (SD). However, none of the studies have investigated the relationship between DENV-1 genotypes and SD. To understand the association between DENV-1 genotypes and SD, the clinical manifestations of patients infected with different genotypes were investigated. A total of 122 patients with confirmed DENV-1 genotype infection were recruited for this study. The clinical manifestations, laboratory tests, and levels of inflammatory mediator factors were statistically analyzed to investigate the characteristics of clinical manifestations and immune response on the DENV-1 genotype. In the case of DENV-1 infection, the incidence of SD with genotype V infection was significantly higher than that with genotype I infection. Meanwhile, patients infected with genotype V were more common in ostealgia and bleeding significantly. In addition, levels of inflammatory mediator factors including IFN-γ, TNF-α, IL-10, and soluble vascular cell adhesion molecule 1 were higher in patients with SD infected with genotype V. Meanwhile, the concentrations of regulated upon activation normal T-cell expressed and secreted and growth-related gene alpha were lower in patients with SD infected with genotype V. The higher incidence of SD in patients infected with DENV-1 genotype V may be attributed to elevated cytokines and adhesion molecules, along with decreased chemokines.

Severe disease during both primary and secondary dengue virus infections in pediatric populations.

Dengue is a global epidemic causing over 100 million cases annually. The clinical symptoms range from mild fever to severe hemorrhage and shock, including some fatalities. The current paradigm is that these severe dengue cases occur mostly during secondary infections due to antibody-dependent enhancement after infection with a different dengue virus serotype. India has the highest dengue burden worldwide, but little is known about disease severity and its association with primary and secondary dengue infections. To address this issue, we examined 619 children with febrile dengue-confirmed infection from three hospitals in different regions of India. We classified primary and secondary infections based on IgM:IgG ratios using a dengue-specific enzyme-linked immunosorbent assay according to the World Health Organization guidelines. We found that primary dengue infections accounted for more than half of total clinical cases (344 of 619), severe dengue cases (112 of 202) and fatalities (5 of 7). Consistent with the classification based on binding antibody data, dengue neutralizing antibody titers were also significantly lower in primary infections compared to secondary infections (P ≤ 0.0001). Our findings question the currently widely held belief that severe dengue is associated predominantly with secondary infections and emphasizes the importance of developing vaccines or treatments to protect dengue-naive populations.

Harness risk stratification of diabetic patients with dengue in a cohort study.

BACKGROUND: Identifying predictors of severe dengue (SD) is key for triage and management of patients as well as for advising travellers to countries where dengue is endemic. In this, meta-analyses have raised diabetes mellitus as a risk factor for SD and a prognostic factor for dengue-related mortality. The purpose of this study was to assess whether diabetic patients (DPs) are at increased risk for SD in comparison to non-diabetic patients (NDPs) in a setting of high prevalence of type 2 diabetes mellitus and increasing endemicity for dengue. METHODS: In a cohort study conducted during the 2019 dengue epidemic on Reunion Island, we estimated the risk ratios (RR) of DPs for SD (WHO 2009 definition), hospitalisation, intensive care unit (ICU) admission, critical care need or death in the ICU, and scales rating severity or multiple organ dysfunction syndrome (MODS), among confirmed cases of dengue (positive RT-PCR or NS1 antigen). RESULTS: In a Poisson regression model adjusted for age, gender and comorbidity, DPs were more likely to develop SD (adjusted RR: 1.46, 95%CI 1.10-1.95), to be hospitalised, admitted to the ICU, and need critical care or die in the ICU. Subgroup analyses identified female DPs, non-elderly DPs (< 65 years) and DPs with low Charlson score (< 3) to be at higher risk for SD, the two first subgroups trough more severe presentation (higher Simplified Acute Physiology Score-2 values; higher MODS scores, respectively). Male gender, age less than 65 years and mixed comorbidity were identified as prognostic factors for critical care need or death in the ICU, male and non-elderly DPs being more likely to develop MODS than their non-diabetic counterparts. CONCLUSIONS: Together, these data highlight the role of diabetes mellitus in the progression from dengue to SD through higher severity per se or the event of MODS.

Risk factors associated with severe dengue in Latin America: A systematic review and meta-analysis.

OBJECTIVE: Severe dengue is a significant health problem in Latin America, with children being the most affected. Understanding risk factors for severe dengue is crucial for enhancing patient care. Therefore, this study aims to systematically review the literature to identify the risk factors associated with severe dengue in Latin America through systematic review and meta-analysis. METHODS: PubMed, SciELO, LILACS and EMBASE databases were used to search for eligible scientific articles for the review. The outcomes considered were symptoms of severe dengue, hospitalisation and death. The Joanna Briggs Institute Critical Appraisal Checklist was used to assess the quality of the studies. Data analysis was performed using STATA v 13.0 software. The degree of heterogeneity between studies was quantified using the I2 measure, and statistically significant results were defined as those with p values <0.05. RESULTS: Of the 1876 articles screened, 47 articles were included in the systematic review and 45 articles were analysed through meta-analysis. Identified risk factors associated with severe dengue included secondary dengue infection, female sex, white or Caucasian ethnicity and specific signs and symptoms such as headache, myalgia and/or arthralgia, vomiting/nausea, abdominal pain or tenderness, diarrhoea, prostration, lethargy, fatigue or similar. For the death outcome, respiratory symptoms and age <18 years were identified as risk factors. On the other hand, in women, the diagnosis of positive tourniquet test, platelet count <100,000 per µL and symptoms of capillary fragility were associated with a lower probability of death. These data highlight the importance of early screening of patients, to identify possible haemorrhagic signs and reduce deaths from dengue. This study has limitations, including possible publication bias, heterogeneity of results and study design biases. CONCLUSION: These findings are significant for shaping strategies, management approaches and identifying high-risk groups, which will help establish future guidelines.

Markers of prolonged hospitalisation in severe dengue.

BACKGROUND: Dengue is one of the most common diseases in the tropics and subtropics. Whilst mortality is a rare event when adequate supportive care can be provided, a large number of patients get hospitalised with dengue every year that places a heavy burden on local health systems. A better understanding of the support required at the time of hospitalisation is therefore of critical importance for healthcare planning, especially when resources are limited during major outbreaks. METHODS: Here we performed a retrospective analysis of clinical data from over 1500 individuals hospitalised with dengue in Vietnam between 2017 and 2019. Using a broad panel of potential biomarkers, we sought to evaluate robust predictors of prolonged hospitalisation periods. RESULTS: Our analyses revealed a lead-time bias, whereby early admission to hospital correlates with longer hospital stays - irrespective of disease severity. Importantly, taking into account the symptom duration prior to hospitalisation significantly affects observed associations between hospitalisation length and previously reported risk markers of prolonged stays, which themselves showed marked inter-annual variations. Once corrected for symptom duration, age, temperature at admission and elevated neutrophil-to-lymphocyte ratio were found predictive of longer hospitalisation periods. CONCLUSION: This study demonstrates that the time since dengue symptom onset is one of the most significant predictors for the length of hospital stays, independent of the assigned severity score. Pre-hospital symptom durations need to be accounted for to evaluate clinically relevant biomarkers of dengue hospitalisation trajectories.

Descriptive and comparative analysis of mucocutaneous manifestations in patients with dengue fever: A prospective study.

BACKGROUND: Dengue is an arbovirosis affecting nearly 4 billion people worldwide. Since 2018, dengue has been re-emerging in Reunion Island. The incidence of mucocutaneous manifestations varies according to the studies and is generally called 'rash'. OBJECTIVES: To assess the prevalence of different mucocutaneous symptoms and describe the characteristics of patients developing these symptoms and the clinical signs associated with severe dengue. METHODS: A prospective study was conducted in 2019 at the University Hospital of La Réunion, in patients presenting a positive PCR for dengue. Descriptive analyses were performed. All cases in the prospective study were examined by a dermatologist. RESULTS: A total of 163 cases were included. The prevalence of mucocutaneous signs was 80.4%. A pruritus was reported in 33.7% cases, an erythematous rash in 29.4% and a mouth involvement including lip, tongue, cheek, angular cheilitis, pharyngitis, mouth ulcer and gingivitis in 31.3%. Most of symptoms appeared in the first days, but some of them could disappear only after the 3rd week. Mucocutaneous signs were not associated with a severe dengue fever (p = 0.54), but ecchymotic purpura was (p = 0.037). In multivariate analysis, skin involvement was associated with flu-like syndrome (headache, pharyngitis, rachis pain) and patient required rehydration but not invasive reanimation. CONCLUSION: This work confirms the high prevalence of skin symptoms in dengue disease, but also their wide diversity. The mucocutaneous involvement of dengue fever appears to be accompanied by a pronounced flu-like syndrome in people without severity, but careful examination to identify ecchymotic purpura or sign of dehydration in the mucous membranes would better identify cases that may worsen.

Association of cardiovascular disease with severe dengue: A systematic review and meta-analysis.

BACKGROUND: Cardiovascular disease (CVD) and dengue are both significant global health concerns, and their intersection presents a growing clinical challenge. Emerging evidence suggests that individuals with pre-existing CVD may face an elevated risk of severe dengue outcomes. The present study aims to perform a systematic review to assess the relationship between CVD and the severity of dengue. METHODS: We conducted a literature search across multiple databases from inception to November 25, 2023. Primary studies reporting the number of dengue patients with CVD in severe dengue and non-severe dengue groups were included. Quality assessment was performed using the Newcastle-Ottawa Scale, and a meta-analysis was conducted using R software version 4.2 to determine the pooled Relative Risk (RR). The study protocol has been registered in PROSPERO. RESULTS: Based on data from 5 studies involving 274,576 dengue patients, our meta-analysis revealed a significant association between CVD and an increased risk of severe dengue, with a calculated RR of 2.71 (95  % CI: 1.03 to 7.10). However, substantial heterogeneity was observed among the included studies (I2 = 79  %). CONCLUSION: The current evidence suggests an association between CVD and severe dengue, emphasizing the importance of closely monitoring individuals with pre-existing cardiovascular disease and providing them with targeted interventions upon dengue diagnosis to mitigate the risk of severe outcomes.

Spatial model of Dengue Hemorrhagic Fever (DHF) risk: scoping review.

BACKGROUND: Creating a spatial model of dengue fever risk is challenging duet to many interrelated factors that could affect dengue. Therefore, it is crucial to understand how these critical factors interact and to create reliable predictive models that can be used to mitigate and control the spread of dengue. METHODS: This scoping review aims to provide a comprehensive overview of the important predictors, and spatial modelling tools capable of producing Dengue Haemorrhagic Fever (DHF) risk maps. We conducted a methodical exploration utilizing diverse sources, i.e., PubMed, Scopus, Science Direct, and Google Scholar. The following data were extracted from articles published between January 2011 to August 2022: country, region, administrative level, type of scale, spatial model, dengue data use, and categories of predictors. Applying the eligibility criteria, 45 out of 1,349 articles were selected. RESULTS: A variety of models and techniques were used to identify DHF risk areas with an arrangement of various multiple-criteria decision-making, statistical, and machine learning technique. We found that there was no pattern of predictor use associated with particular approaches. Instead, a wide range of predictors was used to create the DHF risk maps. These predictors may include climatology factors (e.g., temperature, rainfall, humidity), epidemiological factors (population, demographics, socio-economic, previous DHF cases), environmental factors (land-use, elevation), and relevant factors. CONCLUSIONS: DHF risk spatial models are useful tools for detecting high-risk locations and driving proactive public health initiatives. Relying on geographical and environmental elements, these models ignored the impact of human behaviour and social dynamics. To improve the prediction accuracy, there is a need for a more comprehensive approach to understand DHF transmission dynamics.

Dengue hemorrhagic fever: a growing global menace.

Dengue virus is an arthropod-borne virus, transmitted by Aedes aegypti among humans. In this review, we discussed the epidemiology of dengue hemorrhagic fever (DHF) as well as the disease's natural history, cycles of transmission, clinical diagnosis, aetiology, prevention, therapy, and management. A systematic literature search was done by databases such as PubMed and Google Scholar using search terms, 'dengue fever', 'symptoms and causes of dengue fever', 'dengue virus transmission', and 'strategies to control dengue'. We reviewed relevant literature to identify hazards related to DHF and the most recent recommendations for its management and prevention. Clinical signs and symptoms of dengue infection range from mild dengue fever (DF) to potentially lethal conditions like DHF or dengue shock syndrome (DSS). Acute-onset high fever, muscle and joint pain, myalgia, a rash on the skin, hemorrhagic episodes, and circulatory shock are among the most common symptoms. An early diagnosis is vital to lower mortality. As dengue virus infections are self-limiting, but in tropical and subtropical areas, dengue infection has become a public health concern. Hence, developing and executing long-term control policies that can reduce the global burden of DHF is a major issue for public health specialists everywhere.

Changing pattern of circulating dengue serotypes in the endemic region: An alarming risk to the healthcare system during the pandemic.

BACKGROUND: The pandemic of COVID-19 has created an unprecedented burden on the healthcare system and medical communities resulting in new public health challenges. On the other hand, in tropical countries, another concern arises due to the similar spectrum of clinical manifestations between COVID-19 and dengue fever. Thus, the neglected tropical disease 'Dengue' writhed with more inattention. This study aims to find the effect of the COVID-19 pandemic on dengue infections in endemic areas of West Bengal, India, and their combined impact on public health. The alterations in circulating dengue serotype and their genomic diversity in different COVID-19 waves were also monitored. METHODS: A total of 1782 patients were included in this study. Dengue NS1 ELISA, molecular serotyping, genotyping and their phylogenetic analysis were performed. GISaided analysis of various dengue serotypes and hotspot identification for risk maps of severe dengue in endemic zones were done. The burden of dengue fever and the sustainability of their viral strains with changing meteorological parameters in parallel to COVID-19 waves were analyzed. RESULTS: Co-circulation of all the four dengue serotypes with rapid change in the pattern of prevalent serotype DENV4 (Genotype-I) in the year 2020 and DENV3 (Genotype-III) in 2021 were observed, in parallel to different circulating strains of COVID-19. Spatiotemporal distribution of DENV using Geographic Information System (GIS) applications observed a serotypic shift and hotspot mapping for risk analysis detected Kolkata as a dengue hotspot, which has also reported the maximum number of COVID-19 cases. CONCLUSION: This study indicates the increased fitness of circulating dengue virus strains with optimal virulence as per changing environmental conditions and the inhabitant's immunity. The high infectivity rate of both the RNA viruses and considering.the consequences of severe dengue and COVID-19 in the population of the same geographical settings is an alarming risk.

Dengue virus serotype did not contribute to clinical severity or mortality in Taiwan's largest dengue outbreak in 2015.

BACKGROUND: Dengue virus serotype 2 (DENV-2) was the major serotype in the 2015 dengue outbreak in Taiwan, while DENV-1 and DENV-3 were dominant between 2005 and 2014. We aimed to investigate whether DENV-2 contributed to disease severity and mortality in the outbreak in Kaohsiung city, Taiwan. METHODS: We collected serum samples from dengue patients to detect the presence of DENV and determine the serotypes by using quantitative reverse transcription-polymerase chain reaction. Our cohorts comprised 105 DENV-1-infected cases and 1,550 DENV-2-infected cases. Demographic data, DENV serotype, and comorbidities were covariates for univariate and multivariate analyses to explore the association with severity and mortality. RESULTS: The results suggested that DENV-1 persisted and circulated, while DENV-2 was dominant during the dengue outbreak that occurred between September and December 2015. However, DENV-2 did not directly contribute to either severity or mortality. Aged patients and patients with diabetes mellitus (DM) or moderate to severe chronic kidney disease (CKD) had a higher risk of developing severe dengue. The mortality of dengue patients was related to a higher Charlson comorbidity index score and severe dengue. Among DENV-2-infected patients and older patients, preexisting anti-dengue IgG, DM, and moderate to severe CKD were associated with severe dengue. Moreover, female sex and severe dengue were associated with a significantly higher risk of death. CONCLUSIONS: Our findings highlight the importance of timely serological testing in elderly patients to identify potential secondary infections and focus on the meticulous management of elderly patients with DM or moderate to severe CKD to reduce dengue-related death.

Severity of Dengue Viral Infection Based on Clinical and Hematological Parameters among Pakistani Patients.

The global burden of dengue infections has increased dramatically. Early diagnosis of dengue infection is critical to proper medical management to avoid further complications in patients. This study was geared to assess the severity of dengue infections based on clinical and hematological examinations. A cross-sectional study was conducted among febrile patients with dengue infection in a teaching hospital in Pakistan. Blood samples were investigated for dengue-specific antibodies (IgM and IgG) and the nonstructural 1 antigen. The clinical findings of each subject were noted to assess the severity of the infection. Tests for hematological parameters were performed. Of 130 patients with confirmed dengue infection, 23 had severe and 107 had nonsevere dengue. Patients with severe dengue experienced mucosal bleeding (71.4%), fluid accumulation (57.1%), shock (35.7%), and gastrointestinal bleeding (28.6%). The most significant hematological findings among severe and nonsevere patients with dengue infection were thrombocytopenia, leukopenia, and a raised hematocrit level (P < 0.001). Patients with severe dengue infection showed marked thrombocytopenia, with a mean platelet count of 49.96 × 109 platelets/L. The clinical presentation of patients with dengue infection along with hematological markers are the most important clues for the diagnosis of, prognosis of, and therapy for dengue infection. Thrombocytopenia, leukopenia, and raised hematocrit levels were the most significant hematological parameters when assessing the severity of dengue infection.

A predictive score for severity in patients with confirmed dengue fever in a tertiary care hospital in Kerala, India.

BACKGROUND: The study aimed to identify predictors of severe dengue during the 2017 epidemic and to develop and validate a simple predictive score for severity. METHODS: A retrospective analytical study was conducted using clinical and laboratory data from adult dengue patients with a confirmed microbiological diagnosis. The study included patients who presented to a tertiary care centre in Kerala, India, during the febrile phase (≤4 d) between June 2017 and February 2019. Using appropriate statistical tests, we derived predictors of severe disease and computed a risk score model. RESULTS: Of the 153 patients (mean age 50±17 y; 64% males), 31 (20%) had severe dengue and 4 (3%) died. Petechial lesions, hypoalbuminemia (<3.5 g/dl), elevated alanine aminotransferase (>40 IU/l) and urea >40 IU/l were significant predictors. Our scoring system (cut-off: 2) showed excellent performance, with an area under the receiver operating characteristics curve of 0.9741, sensitivity of 100%, specificity of 96% and accuracy of 98%. The risk score was secondarily validated on 48 patients hospitalized from March 2019 to June 2019. CONCLUSION: Our scoring system is easy to implement and will help primary healthcare practitioners in promptly identifying severe dengue cases upon hospital presentation.

Direct and indirect effects of age on dengue severity: The mediating role of secondary infection.

Severe dengue occurrence has been attributed to increasing age and different dengue virus (DENV) serotypes that cause secondary infections and immune-enhancing phenomena. Therefore, we examined if the effect of age on dengue severity was mediated by infectivity status while controlling for sex and region. Further, we assessed the spatial clustering of dengue severity for individuals with primary and secondary infection across Mexican municipalities. Health data from 2012 to 2017 was retrieved from Mexico's Ministry of Health. A mediation analysis was performed using multiple logistic regression models based on a directed acyclic graph. The models were explored for the direct effect of age on dengue severity and its indirect impact through secondary infection. In addition, severe dengue clusters were determined in some Northeastern and Southeastern municipalities through spatial analysis. We observed a nonlinear trend between age and severe dengue. There was a downward trend of severe dengue for individuals between 0 and 10 years and an upward trend above 10 years. The effect of age on dengue severity was no longer significant for individuals between 10 and 60 years after introducing infectivity status into the model. The mediating role of infectivity status in the causal model was 17%. Clustering of severe dengue among individuals with primary infection in the Northeastern region may point to the high prevalence of DENV-3 in the region. Public health efforts may prevent secondary infection among infants and the aged. In addition, there should be a further investigation into the effect of DENV-3 in individuals with primary disease.