Why are people with dengue dying? A scoping review of determinants for dengue mortality

Dengue hospitalizations and in-hospital mortality changes in trend in Ecuador: a nationwide study from 2015 to 2022

OBJECTIVE

This study aimed to analyze dengue hospitalizations and in-hospital mortality trends in Ecuador, along with sociodemographic factors influencing adverse outcomes.

METHODS

This study included 31,616 dengue hospitalizations in Ecuador during 2015-2022, of which 115 (0.36%) died. Data were extracted from national hospital registries. Age adjusted rates were calculated, and for the analysis of changes in trend, a Joinpoint regression was performed. Multivariate binary and multinomial logistic regressions were performed for assessing sociodemographic factors influencing dengue adverse outcomes.

RESULTS

During 2015-2022, the mean age adjusted dengue hospitalization rate was 22.3 per 100,000 inhabitants with 49.41% annual decrease during 2015-2017 and 31.73% annual increase during 2017-2022 with higher rates in 2020 with 31.61, 2021 with 34.42, and 2022 with 25.81. The mean dengue in-hospital mortality rate was 0.08, mortality rates did not show significant changes during 2015-2022. Higher probability of death was observed in ages ≥50 years and ethnic minorities. People living in rural areas exhibited a 64% higher risk for complicated dengue hospitalization.

CONCLUSIONS

It was observed as an important accomplishment in Ecuador's ongoing efforts to improve healthcare regarding dengue. 0.36% of dengue hospitalizations ended in death which is below the recommended 1%. The increase in dengue hospitalizations in Ecuador during recent years remains a concern. The COVID-19 pandemic might have influenced dengue prevention and vector control to be neglected leading to an increase in cases.

Dengue Treatment-Seeking Behavior: A Qualitative Study With Costa Rican Residents

Treatment-seeking behavior (TSB) in relation to dengue infection is a critical aspect of public health, and understanding the factors that influence it is crucial for effective disease management. This research delves into key determinants of dengue TSB by examining the perceptions and behaviors of individuals in Costa Rica, in relation to the Health Belief Model (HBM). This study utilized naturalistic inquiry and incorporated a qualitative research design involving nine students organized into four teams, with at least one student on each team with high Spanish fluency. In total, we initiated 102 semi-structured field interviews with Costa Rican residents in four communities. The interviews were recorded, transcribed verbatim, and coded in several cycles using MAXQDA 2022©. Thematic analysis was used to identify patterns and themes using an inductive approach. We found that several HBM themes influenced dengue TSB among participants. Self-treatment was the most common initial step in managing dengue. Perceived inaccessibility of health care services and perceived ineffective treatment options discouraged medical care-seeking. Ultimately, the prevalence of self-treatment practices suggests a need for interventions that emphasize the importance of timely professional medical attention, while addressing real barriers and perceptions of existing health care services as inaccessible and ineffective. These findings provide a key perspective on dengue TSB, guiding future public health strategies aimed at optimizing health-seeking behaviors and mitigating the negative impacts of dengue on population health.

Determinants and prevalence of symptomatic dengue fever among adults in the Central Region of Burkina Faso: a hospital-based cross-sectional study

BACKGROUND

Dengue fever (DF) is a significant public health concern in Burkina Faso, particularly in the Central Region, previously endemic for malaria. However, limited research has focused on dengue prevalence and associated factors among adult febrile patients in this region. This study aimed to estimate the prevalence of symptomatic dengue fever among adults and identify the sociodemographic and clinical determinants of the disease.

METHODS

A seroepidemiological cross-sectional study was conducted in the Central Region of Burkina Faso, through a three-stage sampling. Five health facilities, one from each of the region five districts, were purposively selected. Febrile patients aged 16 and older, suspected of having dengue, were included in the study, after consenting. Bivariate analyses and multivariate binary logistic regression were done at a 5% confidence level.

RESULTS

A total of 637 patients between the ages of 16 and 90 years were included. Most of the participants were females (58.71%). Most dengue cases resided in Arrondissement 4 (59.62%), or were present in the Arrondissement 4 at daytime during the previous days (51.92%). 52.90% of the participants knew of dengue. Dengue prevalence was estimated at 8.16% (95% CI: 6.16%-10.57%). The most frequent markers for dengue were immunoglobulins M detected in 4.40% (2.94%-6.29%), followed by Antigen NS1 at 4.24% (95% CI: 2.81%-6.11%). The Antigen NS1 marker was associated with myalgia (p = 0.024), vomiting (p < 0.001), hemorrhagic manifestations (p = 0.001), and anorexia (p < 0.001). Staying at Arrondissement 4 (vs staying at Saaba) during daytime (aOR = 2.36 95% CI: 1.03-5.45; p = 0.044) significantly increased the odds of dengue. Dengue cases were about 3 times more likely to have vomited (aOR = 2.99 95% CI: 1.58-5.64; p = 0.001). Participants knowing of dengue (aOR = 0.53 95% CI: 0.29-0.98; p = 0.042) and those coinfected with malaria (aOR = 0.28 95% CI: 0.14-0.57; p < 0.001) instead had reduced odds of dengue.

CONCLUSION

The study revealed a relatively high prevalence of symptomatic dengue fever among adults in the Central Region of Burkina Faso in 2022. These findings emphasize the need for continuous surveillance and targeted control measures. The low coinfection of dengue and malaria warrants further investigation.

Effectiveness of a diagnostic algorithm for dengue based on an artificial neural network

Introduction

Dengue is a disease with a wide clinical spectrum. The early identification of dengue cases is crucial but challenging for health professionals; therefore, it is necessary to have effective diagnostic instruments to initiate timely care.

Objective

To evaluate the effectiveness of an algorithm based on an artificial neural network (ANN) to diagnose dengue in an endemic area.

Methods

A single-center case-control study was conducted in a secondary-care hospital in Ciudad Obregón, Sonora. An algorithm was built with the official operational definitions, which was called the "direct algorithm," and for the ANN algorithm, the brain.js library was used. The data analysis was performed with the diagnostic tests of sensitivity, specificity, positive predictive value (ppv), and negative predictive value (npv), with 95% confidence intervals and Cohen's kappa index.

Results

A total of 233 cases and 233 controls from 2022 were included. The ANN presented a sensitivity of 0.90 (95% CI [0.85, 0.94]), specificity of 0.82 (95% CI [0.77, 0.87]), npv of 0.91 (95% CI [0.87, 0.94]) and ppv of 0.81 (95% CI [0.76, 0.85]) and a kappa of 0.72. The direct algorithm had a sensitivity of 0.97 (95% CI [0.94, 0.99]), specificity of 0.96 (95% CI [0.92, 0.98]), npv 0.97 (95% CI [0.94, 0.98]), ppv 0.96 (95% CI [0.93, 0.98]) and kappa 0.93.

Conclusions

The direct algorithm performed better than the ANN in the diagnosis of dengue.

[Association between schooling and mortality rate from dengue in Brazil]

Dengue may be associated with individual level variables, such as schooling, increasing the risk of illness. The objective of this study is to analyze the disparities in dengue mortality among the least and the most educated in Brazil, from 2010 to 2018. This is a retrospective ecological study of the differences in the mortality rate due to dengue between the less and the more educated people in Brazil, according to the mortality rates due to general dengue, by age, sex, and Federative Unit (UF). A bootstrap and multiple imputation procedure for the variable schooling was implemented to consider the multilevel structure of the data from each UF over the years. For each aggregate bank generated, a multilevel Poisson model was adjusted. The improvement in the education level of the Brazilian population did not reflect on the decrease in mortality from dengue. There was an increase in the mortality rate from dengue in Brazil and an increase in the difference in mortality rates between less and more educated. Regardless of the imputation process, the results showed higher mortality rates from dengue among the less educated. Low schooling affected younger people more pronouncedly.

Unique Immune Blood Markers Between Severe Dengue and Sepsis in Children

BACKGROUND

Pediatric dengue and sepsis share clinical and pathophysiologic aspects. Multiple inflammatory and regulatory cytokines, decoy receptors and vascular permeability factors have been implicated in the pathogenesis of both diseases. The differential pattern and dynamic of these soluble factors, and the relationship with clinical severity between pediatric dengue and sepsis could offer new diagnosis and therapeutic strategies.

METHODS

We evaluated the concentration levels of 11 soluble factors with proinflammatory, regulatory and vascular permeability involvement, in plasma from children with dengue or sepsis, both clinically ranging from mild to severe, in the early, late and convalescence phases of the disease.

RESULTS

During early acute infection, children with sepsis exhibited specific higher concentration levels of IL-6, vascular endothelial growth factor (VEGF), and its soluble decoy receptor II (sVEGFR2) and lower concentration levels of IL-10 and the soluble tumor necrosis factor receptor 2 (sTNFR2), in comparison with children with severe dengue. In addition, the circulating amounts of soluble ST2, and VEGF/sVEGFR2 were widely associated with clinical and laboratory indicators of dengue severity, whereas secondary dengue virus infections were characterized by an enhanced cytokine response, relative to primary infections. In severe forms of dengue, or sepsis, the kinetics and the cytokines response during the late and convalescence phases of the disease also differentiate.

CONCLUSIONS

Dengue virus infection and septic processes in children are characterized by cytokine responses of a specific magnitude, pattern and kinetics, which are implicated in the pathophysiology and clinical outcome of these diseases.

Interferome signature dynamics during the anti-dengue immune response: a systems biology characterization

Dengue virus (DENV) infection manifests as a febrile illness with three distinct phases: early acute, late acute, and convalescent. Dengue can result in clinical manifestations with different degrees of severity, dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Interferons (IFNs) are antiviral cytokines central to the anti-DENV immune response. Notably, the distinct global signature of type I, II, and III interferon-regulated genes (the interferome) remains uncharacterized in dengue patients to date. Therefore, we performed an in-depth cross-study for the integrative analysis of transcriptome data related to DENV infection. Our systems biology analysis shows that the anti-dengue immune response is characterized by the modulation of numerous interferon-regulated genes (IRGs) enriching, for instance, cytokine-mediated signaling (e.g., type I and II IFNs) and chemotaxis, which is then followed by a transcriptional wave of genes associated with cell cycle, also regulated by the IFN cascade. The adjunct analysis of disease stratification potential, followed by a transcriptional meta-analysis of the interferome, indicated genes such as IFI27, ISG15, and CYBRD1 as potential suitable biomarkers of disease severity. Thus, this study characterizes the landscape of the interferome signature in DENV infection, indicating that interferome dynamics are a crucial and central part of the anti-dengue immune response.

Recent Dengue Infection in Bangladesh: A Seasonal Endemic Progressing to Year-long Serious Health Concern

Dengue represents one of the most dangerous mosquito-borne viral diseases. Although the disease has been prevalent around the globe over the centuries, recent outbreaks of dengue have devasted the healthcare delivery system of many countries. Being a global infection, dengue virus (DENV) is endemically present mainly in Latin America and Caribbean countries as well as countries in South Asia. The recent outbreak of DENV infection has indicated an exceptional outbreak of DENV in some countries in South Asia. There has been a serious endemic of DENV during 2019. After a heterogeneous pause, another severe outbreak of DENV was reported in some Asian countries in 2023. Among the Asian countries, Bangladesh has reported an acute upsurge of DENV infection in 2023 with record numbers of fatalities. However, this pattern of DENV has not been detected in neighbors of Bangladesh, such as India or other countries in Southeast Asia. This provides an emergent task of dissecting the present DENV infection in Bangladesh from different angles to get insights for future containment of the DENV infection, not only in Bangladesh but also in other DENV endemic areas or DENV-native areas.

How to cite this article

Akbar SMF, Khan S, Mahtab M, et al. Recent Dengue Infection in Bangladesh: A Seasonal Endemic Progressing to Year-long Serious Health Concern. Euroasian J Hepato-Gastroenterol 2023;13(2):145-151.

Economic burden estimation associated with dengue and chikungunya in Gujarat, India

Background

Dengue and chikungunya have been emerging as major vector-borne diseases. The global burden of the diseases is rising as a public health problem. The complexity of disease is governed by multiple constraints including only symptomatic treatment and inflicts heavy social and economic burden on society. The present study is designed to assess the economic burden of dengue and chikungunya infection by calculating cost per patient in Gujarat, India.

Methods

A total of 210 patients were enrolled in the study from Ahmedabad and Kheda district of Gujarat from May 2018 to December 2019 of which 150 had dengue and 60 chikungunya infections, subject to the willingness of participation in the survey. Information on wage loss days, cost associated with medicines, diagnosis, special food and travel cost, etc., for the calculation of the direct and indirect costs associated with dengue and chikungunya were collected from these participants using a structured questionnaire. Informed consent was taken before including any participant in the study.

Results

In the dengue sample, 86 were males (57.3%) and the rest were females, and in the chikungunya sample, 31 were males (51.7%) and the rest females. The median age of the participants with dengue and chikungunya was 18 (p25 to p75: 8 to 26) and 30 (p25 to p75: 21 to 45) years respectively. Median family income was recorded as Rs 15,000 (p25 to p75: 9000 to 25500) and Rs 12,000 (p25 to p75: 9000 to 18500) for the dengue and chikungunya cases, respectively. The average duration of the illness was observed to be higher in chikungunya (median days (P25 to p75): 15 (7-45)) than dengue (median days (P25 to p75): 10 (5-15)). The median indirect cost in the case of dengue was Rs 1,931 (p25 to p75: 300 to 4500) while Rs 2,550 (p25 to p75: 0 to 5250) was observed for chikungunya cases. Two types of direct cost, namely, direct cost related to medical expenses and direct cost related to other expenses were calculated. Direct cost related to medical expenses was observed to be higher in dengue (Md (P25 to p75): Rs 2,450 (400-5000)) than chikungunya (Md (P25 to p75): Rs 1,500 (150-5200)) while indirect cost related to other expenses were comparable between dengue (Md (P25 to p75): Rs 1,575 (1300-2600)) and chikungunya (Md (P25 to p75): Rs 1500 (850-2850)). The average total cost for one dengue episode was estimated to be Rs 6,860 (3700-12525) whereas it was Rs 7,000 (2550-14000) for one episode of Chikungunya.

Conclusions

Overall, patients have to bear high costs while suffering from dengue and chikungunya infections. Furthermore, the duration of illness while suffering from viral diseases also contributes to the substantial economic burden. Improved knowledge about the impact of the cost and the economic burden associated with dengue and chikungunya will help policymakers allocate and appropriate resources accordingly.

Endothelial Dysfunction, HMGB1, and Dengue: An Enigma to Solve

Dengue is a viral infection caused by dengue virus (DENV), which has a significant impact on public health worldwide. Although most infections are asymptomatic, a series of severe clinical manifestations such as hemorrhage and plasma leakage can occur during the severe presentation of the disease. This suggests that the virus or host immune response may affect the protective function of endothelial barriers, ultimately being considered the most relevant event in severe and fatal dengue pathogenesis. The mechanisms that induce these alterations are diverse. It has been suggested that the high mobility group box 1 protein (HMGB1) may be involved in endothelial dysfunction. This non-histone nuclear protein has different immunomodulatory activities and belongs to the alarmin group. High concentrations of HMGB1 have been detected in patients with several infectious diseases, including dengue, and it could be considered as a biomarker for the early diagnosis of dengue and a predictor of complications of the disease. This review summarizes the main features of dengue infection and describes the known causes associated with endothelial dysfunction, highlighting the involvement and possible relationship between HMGB1 and DENV.

Self-medication dilemma in dengue fever

This paper focuses on the trends of self-medication practices in treating symptoms that may lead to fatal complications in dengue. As dengue is a viral infection with increasing incidence, decision regarding its treatment is mostly affected by public health believes and practices to self-treat the condition by different home remedies, over-the-counter (OTC) drugs or using outdated prescription drugs that proved beneficial in the past experience. Poverty, lack of education, and poor access to health facilities pave the way for making such decisions. Future complications can be averted by raising awareness, counseling the patients and dispensing of pharmaceuticals with strict monitoring.

Spatio-temporal dynamics of dengue-related deaths and associated factors

Since the reintroduction of dengue viruses in 1987, Sao Paulo State (SP), Brazil, has experienced recurrent epidemics in a growing number of municipalities, each time with more cases and deaths. In the present study, we investigated the spatio-temporal dynamics of dengue-related deaths and associated factors in SP. This was an ecological study with spatial and temporal components, based on notified dengue-related deaths in the municipalities of SP between 2007 and 2017. A latent Gaussian Bayesian model with Poisson probability distribution was used to estimate the standardized mortality ratios (SMR) for dengue and relative risks (RR) for the socioeconomic, demographic, healthcare-related, and epidemiological factors considered. Epidemiological factors included the annual information on the number of circulating serotypes. A total of 1,019 dengue-related deaths (0.22 per 100,000 inhabitant-years) between 2007 and 2017 were confirmed in SP by laboratory testing. Mortality increased with age, peaking at 70 years or older (1.41 deaths per 100,000 inhabitant-years). Mortality was highest in 2015, and the highest SMR values were found in the North, Northwest, West, and coastal regions of SP. An increase of one circulating serotype, one standard deviation in the number of years with cases, and one standard deviation in the degree of urbanization were associated with increases of 75, 35, and 45% in the risk of death from dengue, respectively. The risk of death from dengue increased with age, and the distribution of deaths was heterogeneous in space and time. The positive relationship found between the number of dengue serotypes circulating and years with cases at the municipality/micro-region level indicates that this information can be used to identify risk areas, intensify surveillance and control measures, and organize healthcare to better respond to this disease.

Uncovering the Burden of Dengue in Africa: Considerations on Magnitude, Misdiagnosis, and Ancestry

Dengue is a re-emerging neglected disease of major public health importance. This review highlights important considerations for dengue disease in Africa, including epidemiology and underestimation of disease burden in African countries, issues with malaria misdiagnosis and co-infections, and potential evidence of genetic protection from severe dengue disease in populations of African descent. The findings indicate that dengue virus prevalence in African countries and populations may be more widespread than reported data suggests, and that the Aedes mosquito vectors appear to be increasing in dissemination and number. Changes in climate, population, and plastic pollution are expected to worsen the dengue situation in Africa. Dengue misdiagnosis is also a problem in Africa, especially due to the typical non-specific clinical presentation of dengue leading to misdiagnosis as malaria. Finally, research suggests that a protective genetic component against severe dengue exists in African descent populations, but further studies should be conducted to strengthen this association in various populations, taking into consideration socioeconomic factors that may contribute to these findings. The main takeaway is that Africa should not be overlooked when it comes to dengue, and more attention and resources should be devoted to this disease in Africa.

Evaluating Dengue Virus Pathogenesis in Mice and Humans by Histological and Immunohistochemistry Approaches

The analysis of dengue virus (DENV) infected tissues in mice experimental model and in human biopsies/autopsies may support the pathogenesis studies. Through such models, it is possible to investigate possible histopathological changes caused by the infection and detections of different targets of interest, such as viral antigens, immune cells, and cytokines. In this chapter, we showed a brief review of how histological and immunohistochemistry approaches may improve the knowledge in this field.

Brazilian Dengue Virus Type 2-Associated Renal Involvement in a Murine Model: Outcomes after Infection by Two Lineages of the Asian/American Genotype

Dengue virus type 2 (DENV-2) is, traditionally, the most studied serotype due to its association with explosive outbreaks and severe cases. In Brazil, almost 20 years after the first introduction in the 1990s, a new lineage (Lineage II) of the DENV-2 Asian/American genotype emerged and caused an epidemic with severe cases and hospitalizations. Severe dengue includes multiple organ failure, and renal involvement can be potentially related to increased mortality. In order to better understand the role of DENV infection in renal injury, here we aimed to investigate the outcomes of infection with two distinct lineages of DENV-2 Asian/American genotype in the kidney of a murine model. BALB/c mice were infected with Lineages I and II and tissues were submitted to histopathology, immunohistochemistry, histomorphometry and ultrastructural analysis. Blood urea nitrogen (BUN) was detected in blood sample accessed by cardiac puncture. A tendency in kidney weight increase was observed in mice infected with both lineages, but urea levels, on average, were increased only in mice infected with Lineage II. The DENV antigen was detected in the tissue of mice infected with Lineage II and morphological changes were similar to those observed in human dengue cases. Furthermore, the parameters such as organ weight, urea levels and morphometric analysis, showed significant differences between the two lineages in the infected BALB/c, which was demonstrated to be a suitable experimental model for dengue pathophysiology studies in kidneys.

Emerging Mosquito-Borne Viruses Linked to Aedes aegypti and Aedes albopictus: Global Status and Preventive Strategies

Emerging mosquito-borne viruses continue to cause serious health problems and economic burden among billions of people living in and near the tropical belt of the world. The highly invasive mosquito species Aedes aegypti and Aedes albopictus have successively invaded and expanded their presence as key vectors of Chikungunya virus, dengue virus, yellow fever virus, and Zika virus, and that has consecutively led to frequent outbreaks of the corresponding viral diseases. Of note, these two mosquito species have gradually adapted to the changing weather and environmental conditions leading to a shift in the epidemiology of the viral diseases, and facilitated their establishment in new ecozones inhabited by immunologically naive human populations. Many abilities of Ae. aegypti and Ae. albopictus, as vectors of significant arbovirus pathogens, may affect the infection and transmission rates after a bloodmeal, and may influence the vector competence for either virus. We highlight that many collaborating risk factors, for example, the global transportation systems may result in sporadic and more local outbreaks caused by mosquito-borne viruses related to Ae. aegypti and/or Ae. albopictus. Those local outbreaks could in synergy grow and produce larger epidemics with pandemic characters. There is an urgent need for improved surveillance of vector populations, human cases, and reliable prediction models. In summary, we recommend new and innovative strategies for the prevention of these types of infections.

Knowledge gaps in the epidemiology of severe dengue impede vaccine evaluation

The most severe consequences of dengue virus infection include shock, haemorrhage, and major organ failure; however, the frequency of these manifestations varies, and the relative contribution of pre-existing anti-dengue virus antibodies, virus characteristics, and host factors (including age and comorbidities) are not well understood. Reliable characterisation of the epidemiology of severe dengue first depends on the use of consistent definitions of disease severity. As vaccine trials have shown, severe dengue is a crucial interventional endpoint, yet the infrequency of its occurrence necessitates the inclusion of thousands of study participants to appropriately compare its frequency among participants who have and have not been vaccinated. Hospital admission is frequently used as a proxy for severe dengue; however, lack of specificity and variability in clinical practices limit the reliability of this approach. Although previous infection with a dengue virus is the best characterised risk factor for developing severe dengue, the influence of the timing between dengue virus infections and the sequence of dengue virus infections on disease severity is only beginning to be elucidated. To improve our understanding of the diverse factors that shape the clinical spectrum of disease resulting from dengue virus infection, prospective, community-based and clinic-based immunological, virological, genetic, and clinical studies across a range of ages and geographical regions are needed.

Dengue, Severity Paradox, and Socioeconomic Distribution Among Afro-Colombians

BACKGROUND

The clinical presentation of dengue ranges from self-limited mild illness to severe forms, including death. African ancestry is often described as protective against dengue severity. However, in the Latin American context, African ancestry has been associated with increased mortality. This "severity paradox" has been hypothesized as resulting from confounding or heterogeneity by socioeconomic status (SES). However, few systematic analyses have been conducted to investigate the presence and nature of the disparity paradox.

METHODS

We fit Bayesian hierarchical spatiotemporal models using individual-level surveillance data from Cali, Colombia (2012-2017), to assess the overall morbidity and severity burden of notified dengue. We fitted overall and ethnic-specific models to assess the presence of heterogeneity by SES across and within ethnic groups (Afro-Colombian vs. non-Afro-Colombians), conducting sensitivity analyses to account for potential underreporting.

RESULTS

Our study included 65,402 dengue cases and 13,732 (21%) hospitalizations. Overall notified dengue incidence rates did not vary across ethnic groups. Severity risk was higher among Afro-Colombians (risk ratio [RR] = 1.16; 95% Credible Interval [95% CrI] = 1.08, 1.24) but after accounting for underreporting by ethnicity this association was nearly null (RR = 1.02; 95% CrI = 0.97, 1.07). Subsidized health insurance and low-SES were associated with increased overall dengue rates and severity.

CONCLUSION

The paradoxically increased severity among Afro-Colombians can be attributed to differential health-seeking behaviors and reporting among Afro-Colombians. Such differential reporting can be understood as a type of intersectionality between SES, insurance scheme, and ethnicity that requires a quantitative assessment in future studies.

Social, health system and clinical determinants of fever mortality during an outbreak of dengue fever in Kerala, India

Background and Objectives:

The morbidity and mortality spectrum of the south Indian state of Kerala is dominated by chronic non-communicable diseases, yet febrile illnesses because of neglected tropical diseases and emerging viral infections are often reported. As fever deaths are mostly avoidable, understanding the determinants of mortality is essential for implementing preventive measures.

Methods:

A case-control study was done during an ongoing dengue outbreak in Thiruvananthapuram district, Kerala during 2017–18. Cases included all fever deaths from the line list of Integrated Disease Surveillance Program (IDSP). Data were obtained from hospital case records and by interviewing patients or care givers. The theoretical model for determinants of mortality was constructed at three levels namely sociodemographic factors, access to health care and health seeking behavior, and clinical determinants.

Results:

This study confirmed association of mortality with age above 40 years (P = 0.010, OR = 3.48), being heavy built (P = 0.029, OR = 13.25), clinical symptoms of breathlessness (P < 0.001, OR = 24.89), restlessness (P < 0.001, OR = 97.26), clinical signs of drowsiness (P = 0.024, OR = 7.97), hypotension (P < 0.001, OR = 42.22), complications such as ARDS (P = 0.047, OR = 171.56), and myocarditis (P = 0.012, OR = 16.59). A low occupation status of semiskilled work or less (P = 0.012, OR = 0.30), choosing a nearby hospital for treatment (P = 0.018, OR = 0.48) and shortening the time gap between onset of symptom and final diagnosis (P = 0.044, OR = 0.72) was found to be protective.

Conclusion:

Along with biological and clinical factors, distal determinants like social factors, health seeking behavior, and health system factors are associated with fever mortality.

Daily Quality-of-life Impact of Scars: An Interview-based Foundational Study of Patient-reported Themes

Background:

Scars negatively impact mental health. Prior patient interview studies on cutaneous scars have elicited opinions pertaining to psychosocial effects, appearance, and symptoms. There remains a need for patient-reported opinions in broader contexts, including career and sexual well-being, to better understand patients’ experiences with their cutaneous scars.

Methods:

In this qualitative study, patients with cutaneous scars participated in semi-structured interviews. Transcripts were analyzed using a constant comparative approach using the data software QDAMiner, to generate a thematic framework encompassing patients’ experience with cutaneous scars.

Results:

In total, 37 patients aged 25–79 years (mean 45, SD 17.9) were interviewed. Patients presented with keloid (2/37, 5%), hypertrophic (5/37, 14%), atrophic (4/37, 11%), and linear surgical (18/37, 49%) scars. Opinions fell under 8 overarching themes. Patients spoke commonly about psychological and social well-being (references to the frequency of thinking about a scar and talking about scars with others were mentioned 56 times by 26 patients and 103 times by 29 patients, respectively, for example). Discussions of sexual well-being and career were elicited but rarer (references to feeling uncomfortable when naked and negative impacts on professional networking were mentioned 17 times by 7 patients and 5 times by 3 patients, respectively, for example).

Conclusions:

The relationship between determinants of patients’ opinions of their scars and their impact on quality-of-life is complex. These results expand upon the existing knowledge of the effects scars have on quality-of-life and can contribute to the development and validation of future scar outcome measures.

Causes of death among dengue patients causes of death among hospitalized adults with dengue fever in Tainan, 2015: Emphasis on cardiac events and bacterial infections

INTRODUCTION

The 2015 dengue outbreak in southern Taiwan caused substantial mortality. We analyzed the causes of death among these patients.

MATERIALS AND METHODS

This retrospective study was conducted at a medical center in Tainan from August 2015 to December 2015. Dengue was diagnosed based on the detection of serum dengue NS1 antigen, IgM, or viral RNA in the blood. Causes of death were retrieved from chart reviews by three clinicians.

RESULTS

There were 4488 cases of dengue in the study hospital, with an in-hospital fatality rate of 1.3% (60 cases). The mean age of the 60 fatal cases was 73 years, among whom 90% were aged ≥65 years. Twenty-eight (46.7%) patients died of severe dengue, and 29 (48.3%) deaths were possibly related to dengue. Of the latter, 24 (40%) died of secondary infections. Thirteen cardiac arrest events, including out-of-hospital (5 events) and in-hospital (8) cardiac arrests in the emergency department, occurred during the dengue epidemic. Seven (53.8%) patients did not receive medical aid before the event. Of the 40 deaths that occurred within one week after hospitalization, 60% died of severe dengue. In contrast, 50% of 20 deaths that occurred one week after hospitalization were related to hospital-acquired infections, mainly pneumonia.

CONCLUSION

Of 60 fatal cases, with a predominance of elderly patients, deaths were related to severe dengue within the first week after admission and secondary infections thereafter. The absence of medical care before cardiac arrest events highlights the importance of health education for warning signs of dengue.

Data quality and arbovirus infection associated factors in pregnant and non-pregnant women of childbearing age in Brazil: A surveillance database analysis

The dengue surveillance system in Brazil has registered changes in the disease's morbidity and mortality profile over successive epidemics. Vulnerable groups, such as pregnant women, have been particularly hard hit. This study assessed the quality of notifications of dengue cases among pregnant women and non-pregnant women of childbearing age in Brazil, in addition to discussing the factors associated with arbovirus infection in the group of pregnant women. We carried out a retrospective study of cases registered in the national arbovirus surveillance system between 2007 and 2017. The indicator for assessing quality was incompleteness. Logistic regression was used to analyze the association between dengue during pregnancy and sociodemographic, epidemiological, clinical, and laboratory variables. The incompleteness of the data in the notification form for dengue cases in women of childbearing age and pregnant women indicates a significant loss of information. Dengue was shown to be positively associated with Social Determinants of Health in both groups, with more severe effects among pregnant women. The incompleteness of the data can limit the quality of information from the notification system and the national assessment of the situation of the disease in women of childbearing age and pregnant women.

Spatiotemporal distribution and socioeconomic disparities of dengue, chikungunya and Zika in two Latin American cities from 2007 to 2017

OBJECTIVE

To assess the presence, pattern and magnitude of socioeconomic inequalities on dengue, chikungunya and Zika in Latin America, accounting for their spatiotemporal distribution.

METHODS

Using longitudinal surveillance data (reported arboviruses) from Fortaleza, Brazil and Medellin, Colombia (2007-2017), we fit Bayesian hierarchical models with structured random effects to estimate: (i) spatiotemporally adjusted incidence rates; (ii) Relative Concentration Index and Absolute Concentration Index of inequality; (iii) temporal trends in RCIs; and (iv) socioeconomic-specific estimates of disease distribution. The spatial analysis was conducted at the neighbourhood level (urban settings). The socioeconomic measures were the median monthly household income (MMHI) for Brazil and the Socio-Economic Strata index (SES) in Colombia.

RESULTS

There were 281 426 notified arboviral cases in Fortaleza and 40 887 in Medellin. We observed greater concentration of dengue among residents of low socioeconomic neighbourhoods in both cities: Relative Concentration Index = -0.12 (95% CI = -0.13, -0.10) in Fortaleza and Relative Concentration Index = -0.04 (95% CI = -0.05, -0.03) in Medellin. The magnitude of inequalities varied over time across sites and was larger during outbreaks. We identified a non-monotonic association between disease rates and socioeconomic measures, especially for chikungunya, that changed over time. The Relative Concentration Index and Absolute Concentration Index showed few if any inequalities for Zika. The socioeconomic-specific model showed increased disease rates at MMHI below US$400 in Brazil and at SES-index below level four, in Colombia.

CONCLUSIONS

We provide robust quantitative estimates of socioeconomic inequalities in arboviruses for two Latin American cities. Our findings could inform policymaking by identifying spatial hotspots for arboviruses and targeting strategies to decrease disparities at the local level.

A serological framework to investigate acute primary and post-primary dengue cases reporting across the Philippines

BACKGROUND

In dengue-endemic countries, targeting limited control interventions to populations at risk of severe disease could enable increased efficiency. Individuals who have had their first (primary) dengue infection are at risk of developing more severe secondary disease, thus could be targeted for disease prevention. Currently, there is no reliable algorithm for determining primary and post-primary (infection with more than one flavivirus) status from a single serum sample. In this study, we developed and validated an immune status algorithm using single acute serum samples from reporting patients and investigated dengue immuno-epidemiological patterns across the Philippines.

METHODS

During 2015/2016, a cross-sectional sample of 10,137 dengue case reports provided serum for molecular (anti-DENV PCR) and serological (anti-DENV IgM/G capture ELISA) assay. Using mixture modelling, we re-assessed IgM/G seroprevalence and estimated functional, disease day-specific, IgG:IgM ratios that categorised the reporting population as negative, historical, primary and post-primary for dengue. We validated our algorithm against WHO gold standard criteria and investigated cross-reactivity with Zika by assaying a random subset for anti-ZIKV IgM and IgG. Lastly, using our algorithm, we explored immuno-epidemiological patterns of dengue across the Philippines.

RESULTS

Our modelled IgM and IgG seroprevalence thresholds were lower than kit-provided thresholds. Individuals anti-DENV PCR+ or IgM+ were classified as active dengue infections (83.1%, 6998/8425). IgG- and IgG+ active dengue infections on disease days 1 and 2 were categorised as primary and post-primary, respectively, while those on disease days 3 to 5 with IgG:IgM ratios below and above 0.45 were classified as primary and post-primary, respectively. A significant proportion of post-primary dengue infections had elevated anti-ZIKV IgG inferring previous Zika exposure. Our algorithm achieved 90.5% serological agreement with WHO standard practice. Post-primary dengue infections were more likely to be older and present with severe symptoms. Finally, we identified a spatio-temporal cluster of primary dengue case reporting in northern Luzon during 2016.

CONCLUSIONS

Our dengue immune status algorithm can equip surveillance operations with the means to target dengue control efforts. The algorithm accurately identified primary dengue infections who are at risk of future severe disease.

Dengue Fever: Prognostic Insights From a Complete Blood Count

Introduction

Dengue fever is endemic in more than 100 countries. Early indicators of prognosis are vital to reduce the fatality rate associated with dengue fever. The objective of this study is to investigate the value of a complete blood count (CBC) in determining the prognosis of dengue fever.

Methodology

This was a retrospective study of all patients admitted to Chigateri General and Bapuji hospitals, Davangere over two months. Fifty-six patients were included in the study. Medical records were accessed to obtain data on the clinical profile and laboratory investigations.

Results

Thrombocytopenia was the most common hematological feature, in 50 cases (~90%), followed by leukopenia in 43 cases (~76%). The duration of hospital stay ranged from two to seven days. Interestingly, the percentage of lymphocytes in the differential leukocyte count at the time of admission showed a significant negative correlation with the duration of hospital stay (p=0.028). Also, three distinct trends were observed in the sequence of recovery of platelets and white blood cells (WBCs).

Discussion

A repertoire of prognostic indicators have been described to predict the course and outcome of dengue fever: liver enzymes, interleukins 4 and 10, tumor necrosis factor α (TNFα), some proteases, soluble adhesion molecules, the surface area of atypical lymphocytes, high fluorescent lymphocyte counts, immature granulocytes and immature platelet factor (IPF). However, these markers are not routinely employed due to financial constraints and lack of infrastructure.

The percentage of lymphocytes in the differential leukocyte count performed at the time of admission predicted the length of hospital stay. The higher the percentage of lymphocytes, the faster the recovery from dengue and shorter the duration of stay in the hospital. This is particularly important in remote areas with limited laboratory facilities. High-risk patients can be referred to a higher centre before they develop complications of the disease.

Conclusion

The complete blood count can function as an early indicator of prognosis in dengue fever even in areas where sophisticated biomedical infrastructure is lacking. The lymphocyte percentage on admission could significantly predict the length of hospital stay.

Towards a better integration of social sciences in arbovirus research and decision-making: an experience from scientific collaboration between Cuban and Quebec institutions

In 2017, the Institute of Tropical Medicine Pedro Kourí, University of Montreal Public Health Research Institute, and McGill University joined efforts to provide scenarios for scientific exchange and knowledge dissemination about the social science contribution on arboviral research. This commentary describes the scientific collaboration between Cuban and Canadian (Quebec) institutions, illustrating the need and opportunities to facilitate research and effective decision-making processes for arboviral prevention and control, going beyond traditional biomedical aspects. We organized a set of scientific activities within three international events conducted in Cuba between 2017 and 2018. Given the collaborating institutions' expertise and the knowledge gaps in arboviral research, we selected three main thematic areas: social determinants and equity, community-based interventions and use of evidence for decision-making. The partnership shows that interdisciplinary collaboration and the use and integration of quantitative and qualitative methods from the social sciences is essential to face the current challenges in arbovirus research.

Measuring health related quality of life for dengue patients in Iquitos, Peru

Previous studies measuring the health-related quality of life (HRQoL) of individuals with dengue focused on treatment seeking populations. However, the vast majority of global dengue cases are unlikely to be detected by health systems. Representative measurements of HRQoL should therefore include patients with disease not likely to trigger treatment-seeking behavior. This study based in Iquitos, Peru used the Quality of Wellbeing Scale-Self Administered, a survey that enquires about not only physical health, but also psychological health, self-care, mobility, and usual social activities, and rates HRQoL between 0 (death) and 1 (optimum function), to evaluate the impact of dengue on HRQoL. In order to enroll treatment and non treatment-seeking participants, three modalities of participant recruitment were used. In addition to clinic and community-based febrile surveillance, a contact-cluster methodology was also employed to identify infected individuals less likely to seek treatment. We measured changes in HRQoL and identified common areas of health impairment in 73 virologically confirmed dengue cases at 3 time points during the participant's illness; the early-acute (days 0-6 post symptom onset), late-acute (days 7-20), and convalescent illness phases (days 21 +). Participants reported HRQoL related impairments at significantly higher frequency during the early-acute versus convalescent illness phase (Fisher's exact: P<0.01). There was substantial heterogeneity in scores during each illness phase with median scores in the early-acute, late-acute and convalescent phases of 0.56 (IQR: 0.41-0.64), 0.70 (IQR: 0.57-0.94), and 1 (IQR: 0.80-1.00), respectively. In all illness phases participants recruited in clinics had on average the lowest HRQoL scores where as those recruited in the contact clusters had the highest. Only 1 individual who was recruited in the contact-clusters had no reduction in HRQoL score during their illness. These data illustrate that dengue should be considered as a disease that may have significant implications for not only physical health but also psychological health and social functioning. The impact of dengue on the HRQoL of non-treatment-seeking individuals, although lower than the impact among treatment-seeking individuals, is not necessarily trivial.

Video as a public health knowledge transfer tool in Burkina Faso: A mixed evaluation comparing three narrative genres

BACKGROUND

The dengue virus is endemic in many low- and middle-income countries. In Burkina Faso, the proportion of fevers that could be due to dengue is growing. In 2013, a dengue epidemic spread there, followed by other seasonal outbreaks. Dengue is often confused with malaria, and health workers are not trained to distinguish between them. Three training videos using different narrative genres were tested with nursing students from two institutions in Ouagadougou: journalistic, dramatic and animated video. The study aimed to determine if video is an effective knowledge transfer tool, if narrative genre plays a role in knowledge acquisition, and which narrative elements are the most appreciated.

METHODOLOGY

A mixed method research design was used. The relative effectiveness of the videos was verified through a quasi-experimental quantitative component with a comparison group and post-test measurements. A qualitative component identified participants' perceptions regarding the three videos. Data were drawn from a knowledge test (n = 482), three focus groups with health professionals' students (n = 46), and individual interviews with health professionals (n = 10). Descriptive statistics and single-factor variance analysis were produced. A thematic analysis was used to analyse qualitative data.

PRINCIPAL FINDINGS

Results showed that all three videos led to significant rates of knowledge improvement when compared with the comparison group (p <0.05): 12.31% for the journalistic video, 20.58% for the dramatic video, and 18.91% for the animated video. The dramatic and animated videos produced a significantly higher increase in knowledge than did the journalistic video (with respectively 8.27% (p = 0.003) and 6.59% (p = 0.029) and can be considered equivalent with a difference of 1.68% (p = 0.895). Thematic analysis also revealed that these two videos were considered to be better knowledge transfer tools. Four key aspects are important to consider for a video to be effective: 1) transmitting information in a narrative form, 2) choosing good communicators, 3) creating a visual instrument that reinforces the message and 4) adapting the message to the local context.

CONCLUSIONS

Video has proven to be an effective and appreciated knowledge transfer and training tool for health professionals, but the narrative genre of the videos can influence knowledge acquisition. The production of other videos should be considered for training or updating health professionals and their narrative genre taken into consideration. The actual context of constant circulation of new diseases, such as COVID-19, reaffirms the need to train health professionals.

Fatal Dengue Cases Reveal Brain Injury and Viral Replication in Brain-Resident Cells Associated with the Local Production of Pro-Inflammatory Mediators

Dengue is an arboviral disease caused by dengue virus (DENV), which is transmitted to humans by Aedes aegypti mosquitoes. Infection by DENV most commonly results in a mild flu-like illness; however, the disease has been increasingly associated with neurological symptomatology. This association draws attention to further investigations on the impact of DENV infection in the host's central nervous system. Here, we analyzed brain samples of three fatal dengue cases that occurred in 2002 during an outbreak in Rio de Janeiro, Brazil. Brain tissues of these cases were marked by histopathological alterations, such as degenerated neurons, demyelination, hemorrhage, edema, and increased numbers of astrocytes and microglial cells. Samples were also characterized by lymphocytic infiltrates mainly composed of CD8 T cells. DENV replication was evidenced in neurons, microglia and endothelial cells through immunohistochemistry and in situ hybridization techniques. Pro-inflammatory cytokines, such as TNF-α and IFN-γ were detected in microglia, while endothelial cells were marked by the expression of RANTES/CCL5. Cytoplasmic HMGB1 and the production of nitric oxide were also found in neurons and microglial cells. This work highlights the possible participation of several local pro-inflammatory mediators in the establishment of dengue neuropathogenesis.

Dengue infection in North India: An experience of a tertiary care center from 2012 to 2017

Objective:

Recently, an alarming rise of dengue has been seen in India which remains a major public health concern. This study has been designed for a comprehensive overview of the epidemiology, gender, age, area distribution, symptomology, and seasonal variability.

Materials and Methods:

Retrospective analysis of 900 suspected dengue cases of all age groups of either sex from 2012 to 2017 at a North Indian tertiary care hospital revealed 461 (51.22%) cases seropositive for dengue.

Results:

The age group of 20–30 years was the most affected group with male predominance. The urban population was more affected as 75.05%, and maximum cases were detected in October month followed by November. Common abnormal laboratory parameters were thrombocytopenia (99.1%), hepatic dysfunction (59%), and leukopenia (26.68%). Two uncommon findings, pancytopenia and pancreatic dysfunction were reported in 7 and 3 cases respectively.

Conclusion:

Dengue infection in India has evolved rapidly, and regular outbreaks have been observed with a changing epidemiology, as the disease is rapidly spreading from urban to rural areas with increasing atypical manifestations.

A potential global surveillance tool for effective, low-cost sampling of invasive Aedes mosquito eggs from tyres using adhesive tape

BACKGROUND

The international movement of used tyres is a major factor responsible for global introductions of Aedes invasive mosquitoes (AIMs) (Diptera: Culicidae) that are major disease vectors (e.g. dengue, Zika, chikungunya and yellow fever). Surveillance methods are restricted by expense, availability and efficiency to detect all life stages. Currently, no tested method exists to screen imported used tyres for eggs in diapause, the life stage most at risk from accidental introduction. Here we test the efficiency of adhesive tape as an affordable and readily available material to screen tyres for eggs, testing its effect on hatch rate, larval development, DNA amplification and structural damage on the egg surface.

RESULTS

We demonstrated that the properties of adhesive tape can influence pick up of dormant eggs attached to dry surfaces. Tapes with high levels of adhesion, such as duct tape, removed eggs with high levels of efficiency (97% ± 3.14). Egg numbers collected from cleaned used tyres were found to explain larval hatch rate success well, particularly in subsequent larval to adult emergence experiments. The strength of this relationship decreased when we tested dirty tyres. Damage to the exochorion was observed following scanning electron microscopy (SEM), possibly resulting in the high variance in the observed model. We found that five days was the optimal time for eggs to remain on all tested tapes for maximum return on hatch rate success. Tape type did not inhibit amplification of DNA of eggs from three, five or ten days of exposure. Using this DNA, genotyping of AIMs was possible using species-specific markers.

CONCLUSIONS

We demonstrated for the first time that adhesive tapes are effective at removing AIM eggs from tyres. We propose that this method could be a standardised tool for surveillance to provide public health authorities and researchers with an additional method to screen tyre cargo. We provide a screening protocol for this purpose. This method has a global applicability and in turn can lead to increased predictability of introductions and improve screening methods at high risk entry points.

Bridging Efficacy of a Tetravalent Dengue Vaccine from Children/Adolescents to Adults in Highly Endemic Countries Based on Neutralizing Antibody Response

The CYD-TDV vaccine is licensed in multiple endemic countries based on vaccine efficacy (VE) against symptomatic, virologically confirmed dengue demonstrated in two phase 3 trials (CYD14, 2- to 14-year-olds, Asia; CYD15, 9- to 16-year-olds, Latin America). 50% plaque reduction neutralization test (PRNT₅₀) titers at baseline and month 13 (post-vaccination) were associated with VE and may enable bridging VE to adults. Two phase 2 trials of CYD-TDV measured baseline and month 13 PRNT₅₀ titers: CYD22 (9- to 45-year-olds, Vietnam) and CYD47 (18- to 45-year-olds, India). 50% plaque reduction neutralization test distributions were compared between age cohorts, and four versions of an epidemiological bridging method were used to estimate VE against any serotype (dengue virus [DENV]-Any) and against each serotype over 25 months post first vaccination in a hypothetical CYD14 + CYD15 18- to 45-year-old cohort (bridging population 1) and in the actual CYD47 18- to 45-year-old cohort (bridging population 2). Baseline and month 13 geometric mean PRNT₅₀ titers to each serotype were significantly greater in 18- to 45-year-olds than 9- to 16-year-olds for all comparisons. The four methods estimated VE against DENV-Any at 75.3-86.0% (95% CIs spanning 52.5-100%) for bridging population 1 and 68.4-77.5% (95% CIs spanning 42.3-88.5%) for bridging population 2. The vaccine efficacy against serotype 1, 2, 3, and 4 was estimated at 56.9-76.9%, 68.3-85.8%, 91.4-95.0%, and 93.2-100% (bridging population 1) and 44.5-66.9%, 53.2-69.2%, 79.8-92.0%, and 90.6-95.0% (bridging population 2), respectively; thus, CYD-TDV would likely confer improved efficacy in adults than 9- to 16-year-olds. Using the same methods, we predicted VE against hospitalized DENV-Any over 72 months of follow-up, with estimates 59.1-73.5% (95% CIs spanning 40.9-92.2%) for bridging population 1 and 50.9-65.9% (95% CIs spanning 38.1-82.1%) for bridging population 2.

Dengue Incidence and Sociodemographic Conditions in Pucallpa, Peruvian Amazon: What Role for Modification of the Dengue-Temperature Relationship?

Dengue is a climate-sensitive disease with an increasing global burden. Although the relationship between meteorological conditions and dengue incidence is well established, less is known about the modifying nature of sociodemographic variables on that relationship. We assess the strength and direction of sociodemographic effect modification of the temperature-dengue relationship in the second largest city of the Peruvian Amazon to identify populations that may have heightened vulnerability to dengue under varying climate conditions. We used weekly dengue counts and averaged meteorological variables to evaluate the association between disease incidence, meteorological exposures, and sociodemographic effect modifiers (gender, age, and district) in negative binomial regression models. District was included to consider geographical effect modification. We found that being a young child or elderly, being female, and living in the district of Manantay increased dengue's incidence rate ratio (IRR) as a result of 1°C increase in weekly mean temperature (IRR = 2.99, 95% CI: 1.99-4.50 for women less than 5 years old and IRR = 2.86, 95% CI: = 1.93-4.22 for women older than 65 years, both estimates valid for the rainy season). The effect of temperature on dengue depended on season, with stronger effects during rainy seasons. Sociodemographic variables can provide options for intervention to mitigate health impacts with a changing climate. Our results indicate that patterns of baseline risk between regions and sociodemographic conditions can differ substantially from trends in climate sensitivity. These results challenge the assumption that the distribution of climate change impacts will be patterned similarly to existing social gradients in health.

Considerations for the 2030 Sustainable Development Goals for dengue

Dengue circulates endemically in many tropical and subtropical regions. In 2012, the World Health Organization (WHO) set out goals to reduce dengue mortality and morbidity by 50% and 25%, respectively, between 2010 and 2020. These goals will not be met. This is, in part, due to existing interventions being insufficiently effective to prevent spread. Further, complex and variable patterns of disease presentation coupled with imperfect surveillance systems mean that even tracking changes in burden is rarely possible. As part of the Sustainable Development Goals, WHO will propose new dengue-specific goals for 2030. The 2030 goals provide an opportunity for focused action on tackling dengue burden but should be carefully developed to be ambitious but also technically feasible. Here we discuss the potential for clearly defined case fatality rates and the rollout of new and effective intervention technologies to form the foundation of these future goals. Further, we highlight how the complexity of dengue epidemiology limits the feasibility of goals that instead target dengue outbreaks.

Endemic Disease Control Agents' perception on the fight against Aedes aegypti and the prevention of arbovirus infections in Brazil

BACKGROUND

Arboviruses pose a serious and constant threat to public health, and have demanded surveillance efforts worldwide. The prevention of arbovirus transmission depends on effective measures to control vectors and promote health. The objective of this study was to examine the factors that enhance and impair the endemic disease control agents' field work, based on their own perspective.

METHODOLOGY AND MAIN FINDINGS

In 2017, 65 ACE of seven municipalities participated in a series of seven focus groups in the Zona de Mata mesoregion (Minas Gerais, Brazil). The focus groups were organized aiming to broaden and deepen the discussion and analysis of ACE perception of their performance in relation to attributions, work processes, training, continuous education, and evaluation. All the workers, irrespective of municipality, recognize their role in disease prevention and health promotion, however they suffer from a reductionist stigma associated with their profession. Also, internal and external factors such as infrastructure, resources, administrative management, and the work process affect the quality of service delivered and job satisfaction. Practice challenges include incompatible demands such as refusal by residents and high sense of insecurity related to violence. The respondents reported that success of their activities depend on the population.

CONCLUSIONS/SIGNIFICANCE

The recurrence of epidemics demands effective vector control policies. Therefore, the performance of these professionals as regards surveillance needs to be reassessed. Public awareness and acknowledgement of the role of ACE in the identification of risk and health protection factors are indispensable for the improvement of this workforce.

Predictors of Major Bleeding and Mortality in Dengue Infection: A Retrospective Observational Study in a Tertiary Care Centre in South India

We conducted a retrospective observational study to describe the clinical profile and outcomes of patients admitted with a diagnosis of dengue fever in a tertiary hospital in South India. A total of 159 patients admitted from April 2014 to October 2018 were included in the study. Vomiting (70.4%), myalgia (60.4%), headache (42.1%), abdominal pain (38.4%), bleeding (38%), and rash (37.1%) were the most common symptoms at presentation. The mean duration of hospital stay was 4.9 days (SD ± 2.4), and the median cost was INR 19,708 ($285) (IQR INR 12,968–32,056 ($188–$305)). Major bleeding was associated with elevated SGOT and SGPT, severe dengue, and secondary dengue. Mortality was associated with elderly age; elevated total leukocyte count, serum bilirubin, serum creatinine, SGOT, and SGPT; and high SOFA score. In view of these observations, we recommend stratifying patients according to the WHO classification of dengue and avoiding the use of thrombocytopenia as a single marker of the severity of the illness.

Dengue in Fiji: epidemiology of the 2014 DENV-3 outbreak

Introduction

Dengue virus serotype-3 caused a large community-level outbreak in Fiji in 2013 and 2014. We aimed to characterize the demographic features of affected individuals and to determine dengue mortality during the outbreak.

Methods

All laboratory-confirmed dengue cases and deaths were included in this study. Incidence and mortality were calculated according to demographic variables.

Results

A total of 5221 laboratory-confirmed cases of dengue were included in this analysis. The majority of patients were male (54.5%) and indigenous Fijians (iTaukei) (53.5%). The median age was 25 years old. The overall incidence was 603 per 100 000 population. The age-specific incidence was highest among people between 20 and 24 years of age (1057 per 100 000) for both sexes. The major urban and peri-urban areas of Suva and Rewa subdivisions reported the highest incidence of > 1000 cases per 100 000 population.

Discussion

Dengue morbidity and mortality were highest among males, indigenous people and residents of urban and peri-urban locations. Effective and integrated public health strategies are needed to ensure early detection and appropriate outbreak control measures.

Different Associations between DC-SIGN Promoter-336G/A (rs4804803) Polymorphism with Severe Dengue in Asians and South-Central Americans: a Meta-Analysis

Objective: This study was conducted to identify the association between rs4804803 polymorphism in DC-SIGN with the susceptibility of severe dengue. Methods: A comprehensive search was conducted to identify all eligible papers in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Google Scholar. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were used to assess the association. Subgroup analyses were performed by ethnicity. Sensitivity analyses were performed through employing different statistical models (fixed versus random effect model). Results: A total of nine papers and 12 studies, with 1520 severe dengue and 1496 clinical dengue infection were included. The overall meta-analysis revealed significant associations between rs4804803 and severe dengue under the recession (GG versus GA/AA: OR = 0.44, 95%CI, 0.23–0.82) and a codominant model (GG versus AA: OR = 0.43, 95%CI, 0.23–0.81), but sensitivity analysis indicated that the significant pooled ORs were not robust. The subgroup analysis suggested that the carrier of G in rs4804803 was a risk factor for severe dengue under dominant (GG/GA versus AA: OR = 1.86,95%CI, 1.01–3.45), superdominant (GA versus GG/AA: OR = 1.81,95%CI, 1.02–3.21) and a codominant (GA versus AA: OR=1.82,95%CI, 1.02–3.26) models in Asians, while it was a protective factor for severe dengue in South-central Americans under recessive (GG versus GA/AA: OR = 0.27,95%CI, 0.10–0.70) and codominant (GG versus AA: OR=0.24,95%CI, 0.09–0.64) models. The results from subgroup analysis were robust. Conclusions: Dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) promoter-336G/A (rs4804803) polymorphism is association with severe dengue, and it acts in different directions for Asians and South-central Americans.

Development of a dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF) for targeted antibody blocking

Targeted antibody blocking enables characterization of binding sites on immunoglobulin G (IgG), and can efficiently eliminate harmful antibodies from organisms. In this report, we present a novel peptide-denoted as a dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF)-for targeted blocking of antibodies. Synthesis of DCAF was achieved by native chemical ligation, and the molecule consists of three functional parts: a specific antigenic peptide, a linker and the Fc-III mimetic peptide, which has a high affinity toward the Fc region of IgG molecules. We demonstrate that DCAF binds the cognate antibody with high selectivity by simultaneously binding to the Fab and Fc regions of IgG. Animal experiments revealed that DCAF molecules diminish the antibody-dependent enhancement effect in a dengue virus infection model, and rescue the acetylcholine receptor by inhibiting the complement cascade in a myasthenia gravis model. These results suggest that DCAFs could have utility in the development of new therapeutics against harmful antibodies.

Clinical Indicators of Fatal Dengue in Two Endemic Areas of Colombia: A Hospital-Based Case-Control Study

According to the World Health Organization, 98% of fatal dengue cases can be prevented; however, endemic countries such as Colombia have recorded higher case fatality rates during recent epidemics. We aimed to identify the predictors of mortality that allow risk stratification and timely intervention in patients with dengue. We conducted a hospital-based, case-control (1:2) study in two endemic areas of Colombia (2009-2015). Fatal cases were defined as having either 1) positive serological test (IgM or NS1), 2) positive virological test (RT-PCR or viral isolation), or 3) autopsy findings compatible with death from dengue. Controls (matched by state and year) were hospitalized nonfatal patients and had a positive serological or virological dengue test. Exposure data were extracted from medical records by trained staff. We used conditional logistic regression (adjusting for age, gender, disease's duration, and health-care provider) in the context of multiple imputation to estimate exposure to case-control associations. We evaluated 110 cases and 217 controls (mean age: 35.0 versus 18.9; disease's duration pre-admission: 4.9 versus 5.0 days). In multivariable analysis, retro-ocular pain (odds ratios [OR] = 0.23), nausea (OR = 0.29), and diarrhea (OR = 0.19) were less prevalent among fatal than nonfatal cases, whereas increased age (OR = 2.46 per 10 years), respiratory distress (OR = 16.3), impaired consciousness (OR = 15.9), jaundice (OR = 32.2), and increased heart rate (OR = 2.01 per 10 beats per minute) increased the likelihood of death (AUC: 0.97, 95% confidence interval: 0.96, 0.99). These results provide evidence that features of severe dengue are associated with higher mortality, which strengthens the recommendations related to triaging patients in dengue-endemic areas.

Dengue fever in Dar es Salaam, Tanzania: clinical features and outcome in populations of black and non-black racial category

BACKGROUND

Although the incidence of dengue across Africa is high, severe dengue is reported infrequently. We describe the clinical features and the outcome of dengue according to raceduring an outbreak in Dar es Salaam, Tanzania that occurred in both native and expatriate populations.

METHODS

Adults with confirmed dengue (NS1 and/or IgM on rapid diagnostic test and/or PCR positive) were included between December 2013 and July 2014 in outpatient clinics. Seven-day outcome was assessed by a visit or a call. Association between black race and clinical presentation, including warning signs, was assessed by logistic regression adjusted for age, malaria coinfection, secondary dengue and duration of symptoms at inclusion. The independent association between demographic and comorbidities characteristics of the patients and severe dengue was evaluated by multivariate logistic regression that included potential confounders.

RESULTS

After exclusion of 3 patients of mixed race, 431 patients with dengue (serotype 2, genotype Cosmopolitan) were included: 241 of black and 190 of non-black race. Black patients were younger (median age 30 versus 41 years; p < 0.001) and attended care after a slightly longer duration of symptoms (median of 2.9 versus 2.7 days; p = 0.01). Malaria coinfection was not significantly different between black (5%) and non-black (1.6%) patients (p = 0.06). The same proportion of patients in both group had secondary dengue (13 and 14%; p = 0.78). Among warning signs, only mucosal bleed was associated with race, black race being protective (adjusted OR 0.44; 95% CI 0.21-0.92). Overall, 20 patients (4.7%) presented with severe dengue. Non-black race (adjusted OR 3.9; 95% CI 1.3-12) and previously known diabetes (adjusted OR 43; 95% CI 5.2-361) were independently associated with severe dengue.

CONCLUSIONS

Although all patients were infected with the same dengue virus genotype, black race was independently protective against a severe course of dengue, suggesting the presence of protective genetic or environmental host factors among people of African ancestry. The milder clinical presentation of dengue in black patients might partly explain why dengue outbreaks are under-reported in Africa and often mistaken for malaria. These results highlight the need to introduce point-of-care tests, beside the one for malaria, to detect outbreaks and orientate diagnosis.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT01947075 , retrospectively registered on the 13 of September 2014.

Adult Immunization - Need of the Hour

Immunization is the process of making individuals immune. Childhood immunization is a common process for various aliments, but adult immunization in the Indian scenario is obscure. Officially, India has been declared polio-free, which is an achievement despite cultural, political, economic, geographic, and so many other factors. The changing demographics of adult, geriatric population and growing cost of health-care maintenance are a concern in developing countries like India. Thus, promoting healthy lifestyle needs prevention, early detection, and management of various diseases and disorders. Certainly, prevention in adults is yet to be tapped completely, so that goal of 100% prevention can be achieved. Various fraternities of medical association have come up with guidelines for adult immunization schedules in India. The present paper reviews infectious diseases such as anthrax, chikungunya, cholera, dengue, influenza, and malaria in this section of the review. We humbly request all health-care professionals and educators to educate the mass for adult immunization. So that, cost involved for treatment and workforce for the management of diseases can be better utilized in some other needed areas.

Burden of dengue among febrile patients at the time of chikungunya introduction in Piedecuesta, Colombia

OBJECTIVE

To estimate the age-specific incidence of symptomatic dengue and chikungunya in Colombia.

METHOD

A passive facility-based fever surveillance study was conducted among individuals with undifferentiated fever. Confirmatory diagnostics included serological and molecular tests in paired samples, and surveillance's underreporting was assessed using capture-recapture methods.

RESULTS

Of 839 febrile participants 686 completed the study. There were 33.2% (295/839) dengue infections (51% primary infections), and 35.9% (191/532) of negative dengue cases there were chikungunya cases. On average, dengue cases were younger (median = 18 years) than chikungunya cases (median = 25 years). Thrombocytopaenia and abdominal pain were the main dengue predictors, while presence of rash was the main predictor for chikungunya diagnosis. Underreporting of dengue was 31%; the estimated expansion factors indicate an underreporting rate of dengue cases of threefold for all cases and of almost sixfold for inpatients.

CONCLUSIONS

These findings highlight the ongoing coexistence of both arboviruses, a distinct clinical profile of each condition in the study area that could be used by clinicians to generate a differential diagnosis, and the presence of underreporting, mostly among hospitalised cases.

Impact, economic evaluation, and sustainability of integrated vector management in urban settings to prevent vector-borne diseases: a scoping review

Background

The control of vector-borne diseases (VBD) is one of the greatest challenges on the global health agenda. Rapid and uncontrolled urbanization has heightened the interest in addressing these challenges through an integrated vector management (IVM) approach. The aim was to identify components related to impacts, economic evaluation, and sustainability that might contribute to this integrated approach to VBD prevention.

Main body

We conducted a scoping review of available literature (2000–2016) using PubMed, Web of Science, Cochrane, CINAHL, Econlit, LILACS, Global Health Database, Scopus, and Embase, as well as Tropical Diseases Bulletin, WHOLIS, WHO Pesticide Evaluation Scheme, and Google Scholar. MeSH terms and free-text terms were used. A data extraction form was used, including TIDieR and ASTAIRE. MMAT and CHEERS were used to evaluate quality.

Of the 42 documents reviewed, 30 were focused on dengue, eight on malaria, and two on leishmaniasis. More than a half of the studies were conducted in the Americas. Half used a quantitative descriptive approach (n = 21), followed by cluster randomized controlled trials (n = 11). Regarding impacts, outcomes were: a) use of measures for vector control; b) vector control; c) health measures; and d) social measures. IVM reduced breeding sites, the entomology index, and parasite rates. Results were heterogeneous, with variable magnitudes, but in all cases were favourable to the intervention. Evidence of IVM impacts on health outcomes was very limited but showed reduced incidence. Social outcomes were improved abilities and capacities, empowerment, and community knowledge. Regarding economic evaluation, only four studies performed an economic analysis, and intervention benefits outweighed costs. Cost-effectiveness was dependent on illness incidence. The results provided key elements to analyze sustainability in terms of three dimensions (social, economic, and environmental), emphasizing the implementation of a community-focused eco-bio-social approach.

Conclusions

IVM has an impact on reducing vector breeding sites and the entomology index, but evidence of impacts on health outcomes is limited. Social outcomes are improved abilities and capacities, empowerment, and community knowledge. Economic evaluations are scarce, and cost-effectiveness is dependent on illness incidence. Community capacity building is the main component of sustainability, together with collaboration, institutionalization, and routinization of activities. Findings indicate a great heterogeneity in the interventions and highlight the need for characterizing interventions rigorously to facilitate transferability.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0464-x) contains supplementary material, which is available to authorized users.

30 years of dengue fatal cases in Brazil: a laboratorial-based investigation of 1047 cases

BACKGROUND

Dengue viruses (DENV) have emerged and reemerged in Brazil in the past 30 years causing explosive epidemics. The disease may range from clinically asymptomatic infections to severe and fatal outcomes. We aimed to describe the epidemiological, clinical and laboratorial aspects of the dengue fatal cases received by a Regional Reference Laboratory, Brazil in 30 years.

METHODS

A total of 1047 suspected fatal dengue cases were received from 1986 to 2015 and analyzed in the Laboratory of Flavivirus, FIOCRUZ. Suspected cases were submitted to viral detection, serological and molecular methods for cases confirmation. Influence of gender, age, serotype and type of infection (primary/secondary) on death outcome, as well the interactions between serotype and age or infection and age and type of infection were also studied.

RESULTS

A total of 359 cases (34.2%) were confirmed and DENV-1 (11.1%), DENV-2 (43.9%), DENV-3 (32.8%) and DENV-4 (13.7%) were detected. Overall, fatal cases occurred more often in primary infections (59.3%, p = 0.001). However, in 2008, fatal cases were mainly associated to secondary infections (p = 0.003). In 2008 and 2011, deaths were more frequent on children and those infected by DENV-2 presented a higher risk for fatal outcome. Moreover, children with secondary infections had a 4-fold higher risk for death.

CONCLUSIONS

Dengue is a multifactorial disease and, factors such as viral strain/serotype, occurrence of secondary infections and co-morbidities may lead to a severe outcome. However, the high dengue incidence and transmission during epidemics, such as those observed in Brazil may overwhelm and collapse the public health services, potentially impacting on increased disease severity and mortality.