Persistent Symptoms of Dengue: Estimates of the Incremental Disease and Economic Burden in Mexico

Estimating dengue disease and economic burden to inform municipal-level policymakers: Method for a pragmatic city-level observational cohort study

Background

Recent trials have confirmed the effectiveness of promising dengue control technologies - two vaccines and Wolbachia. These would generally be applied at the municipal level. To help local officials decide which, if any, control strategy to implement, they need affordable, timely, and accurate data on dengue burden. Building on our previous work in Mexico, Indonesia, and Thailand, we developed a streamlined prospective method to estimate dengue burden at the municipal level quickly, accurately, and efficiently.

Methods

The method entails enrolling and repeatedly interviewing 100 patients with laboratory-confirmed dengue. They will be selected after screening and testing about 1,000 patients with clinical dengue. The method will capture both acute and chronic effects relating to disease, economic burden, and psychological impacts (presenteeism). The total time requirements are 1.5 years, comprised of 0.25 years for planning and approvals, 1 year for data collection (a full dengue cycle), and 0 .25 years for data cleaning and analysis. A collaboration with municipal and academic colleagues in the city of Semarang, Central Java, Indonesia shows how the method could be readily applied in Indonesia's eighth largest city (population 1.8 million).

Conclusions

Many surveillance studies gather only information on numbers of cases. This proposed method will provide a comprehensive picture of the dengue burden to the health system, payers, and households at the local level.

Dengue versus COVID-19: comparing the incidence of cardiovascular, neuropsychiatric and autoimmune complications

BACKGROUND

While persistence of chronic symptoms following dengue infection has been documented in small prospective cohorts, population-based studies are limited. The post-acute risk of new-incident multi-systemic complications following dengue infection was contrasted against that following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a multi-ethnic adult Asian population.

METHODS

National testing and healthcare claims that databases in Singapore were utilized to build a retrospective population-based adult cohort with laboratory-confirmed infection during overlapping waves of SARS-CoV-2 and dengue transmission (1 July 2021 to 31 October 2022). Risks of new-incident cardiovascular/neuropsychiatric/autoimmune complications 31-300 days of post-dengue infection, contrasted with SARS-CoV-2 infection, were estimated using Cox regression with overlap weights. Risks were reported in terms of adjusted hazard ratio (aHR) and excess burden per 1000 persons.

RESULTS

11 707 dengue-infected individuals and 1 248 326 contemporaneous coronavirus disease 2019 (COVID-19) cases were included; the majority had mild initial infection not requiring hospitalization. Amongst dengue-infected individuals, there was 21% [aHR = 1.21 (1.06-1.38)] increased risk of any sequelae, with 55% [aHR = 1.55 (1.27-1.89)] increased risk of cardiovascular sequelae. Specifically, increased risk of dysrhythmias [aHR = 1.79(1.35-2.37)], ischemic heart disease [aHR = 1.45(1.12-1.89)], other cardiac disorders [aHR = 2.21(1.54-3.16)] and thrombotic disorders [aHR = 2.55(1.50-4.35)] was noted. Elevated risk of individual neuropsychiatric sequelae, including cerebrovascular disorders [aHR = 1.49(1.09-2.13)], cognition/memory disorders [aHR = 2.13(1.55-2.93)], extrapyramidal/movement disorders [aHR = 1.98(1.33-2.94)] and anxiety disorders [aHR = 1.61(1.01-2.56)], was observed in dengue-infected individuals compared to COVID-19 cases. Elevated risks of post-acute sequelae in dengue survivors were observed when contrasted against COVID-19 survivors infected during Delta/Omicron predominance, as well as across vaccination strata.

CONCLUSION

Increased risk of post-acute cardiovascular/neuropsychiatric complications was observed in dengue survivors, when contrasted against COVID-19 survivors infected during Delta/Omicron predominance.

RESEARCH IN CONTEXT

Parallel prediction of dengue cases with different risks in Mexico using an artificial neural network model considering meteorological data

In 2022, Mexico registered an increase in dengue cases compared to the previous year. On the other hand, the amount of precipitation reported annually was slightly less than the previous year. Similarly, the minimum-mean-maximum temperatures recorded annually were below the previous year. In the literature, it is possible to find studies focused on the spread of dengue only for some specific regions of Mexico. However, given the increase in the number of cases during 2022 in regions not considered by previously published works, this study covers cases reported in all states of the country. On the other hand, determining a relationship between the dynamics of dengue cases and climatic factors through a computational model can provide relevant information on the transmission of the virus. A multiple-learning computational approach was developed to simulate the number of the different risks of dengue cases according to the classification reported per epidemiological week by considering climatic factors in Mexico. For the development of the model, the data were obtained from the reports published in the Epidemiological Panorama of Dengue in Mexico and in the National Meteorological Service. The classification of non-severe dengue, dengue with warning signs, and severe dengue were modeled in parallel through an artificial neural network model. Five variables were considered to train the model: the monthly average of the minimum, mean, and maximum temperatures, the precipitation, and the number of the epidemiological week. The selection of variables in this work is focused on the spread of the different risks of dengue once the mosquito begins transmitting the virus. Therefore, temperature and precipitation were chosen as climatic factors due to the close relationship between the density of adult mosquitoes and the incidence of the disease. The Levenberg-Marquardt algorithm was applied to fit the coefficients during the learning process. In the results, the ANN model simulated the classification of the different risks of dengue with the following precisions (R2): 0.9684, 0.9721, and 0.8001 for non-severe dengue, with alarm signs and severe, respectively. Applying a correlation matrix and a sensitivity analysis of the ANN model coefficients, both the average minimum temperature and precipitation were relevant to predict the number of dengue cases. Finally, the information discovered in this work can support the decision-making of the Ministry of Health to avoid a syndemic between the increase in dengue cases and other seasonal diseases.

The potency of hematopoietic stem cell reprogramming for changing immune tone

Innate immune memory endows innate immune cells with antigen independent heightened responsiveness to subsequent challenges. The durability of this response can be mediated by inflammation induced epigenetic and metabolic reprogramming in hematopoietic stem and progenitor cells (HSPCs) that are maintained through differentiation to mature immune progeny. Understanding the mechanisms and extent of trained immunity induction by pathogens and vaccines, such as BCG, in HSPC remains a critical area of exploration with important implications for health and disease. Here we review these concepts and present new analysis to highlight how inflammatory reprogramming of HSPC can potently alter immune tone, including to enhance specific anti-tumor responses. New findings in the field pave the way for novel HSPC targeting therapeutic strategies in cancer and other contexts of immune modulation. Future studies are expected to unravel diverse and extensive effects of infections, vaccines, microbiota, and sterile inflammation on hematopoietic progenitor cells and begin to illuminate the broad spectrum of immunologic tuning that can be established through altering HSPC phenotypes. The purpose of this review is to draw attention to emerging and speculative topics in this field where we posit that focused study of HSPC in the framework of trained immunity holds significant promise.

Frailty in Older Adults with Dengue Fever

Background and objectives: Dengue is one of the most common epidemic infections around the world. Dengue infections in older adults are related to an atypical presentation and a high mortality. Frailty is associated with poor recovery from hospitalization due to infection. However, few studies describe frailty and functional decline after dengue infection. The current case series study aims to investigate the baseline frailty status, functional decline, and time to recovery in older adults after dengue infection. Method: We studied seven patients with post-dengue frailty who had been admitted to the geriatric ward in one tertiary medical center in Taiwan during the 2023 dengue fever outbreak. Result: The mean age was 82 years old. The clinical frailty scale worsened from a mean of 4.7 at baseline to 6.3 at dengue diagnosis. The mean Katz Index of independence in activities of daily living decreased from 10.6 at baseline to 4.7 with dengue, and it recovered to 6.7 one month after discharge. Conclusions: Our preliminary data suggest that there is indeed an increase in frailty in older adults due to dengue. Post-dengue frailty and functional decline might be profound and persistent. Acute geriatric care intervention rehabilitation for frailty after dengue may benefit this population.

Insights into dengue immunity from vaccine trials

The quest for an effective dengue vaccine has culminated in two approved vaccines and another that has completed phase 3 clinical trials. However, shortcomings exist in each, suggesting that the knowledge on dengue immunity used to develop these vaccines was incomplete. Vaccine trial findings could refine our understanding of dengue immunity, because these are experimentally derived, placebo-controlled data. Results from these trials suggest that neutralizing antibody titers alone are insufficient to inform protection against symptomatic infection, implicating a role for cellular immunity in protection. These findings have relevance for both future dengue vaccine development and application of current vaccines for maximal public health benefit.

An economic evaluation of Wolbachia deployments for dengue control in Vietnam

INTRODUCTION

Dengue is a major public health challenge and a growing problem due to climate change. The release of Aedes aegypti mosquitoes infected with the intracellular bacterium Wolbachia is a novel form of vector control against dengue. However, there remains a need to evaluate the benefits of such an intervention at a large scale. In this paper, we evaluate the potential economic impact and cost-effectiveness of scaled Wolbachia deployments as a form of dengue control in Vietnam-targeted at the highest burden urban areas.

METHODS

Ten settings within Vietnam were identified as priority locations for potential future Wolbachia deployments (using a population replacement strategy). The effectiveness of Wolbachia deployments in reducing the incidence of symptomatic dengue cases was assumed to be 75%. We assumed that the intervention would maintain this effectiveness for at least 20 years (but tested this assumption in the sensitivity analysis). A cost-utility analysis and cost-benefit analysis were conducted.

RESULTS

From the health sector perspective, the Wolbachia intervention was projected to cost US$420 per disability-adjusted life year (DALY) averted. From the societal perspective, the overall cost-effectiveness ratio was negative, i.e. the economic benefits outweighed the costs. These results are contingent on the long-term effectiveness of Wolbachia releases being sustained for 20 years. However, the intervention was still classed as cost-effective across the majority of the settings when assuming only 10 years of benefits.

CONCLUSION

Overall, we found that targeting high burden cities with Wolbachia deployments would be a cost-effective intervention in Vietnam and generate notable broader benefits besides health gains.

Dengue as a Disease Threatening Global Health: A Narrative Review Focusing on Latin America and Brazil

Arboviruses constitute the largest known group of viruses. These viruses are the etiological agents of pathologies known as arboviruses, with dengue being one of the most prevalent. Dengue has resulted in important socioeconomic burdens placed on different countries around the world, including those in Latin America, especially Brazil. Thus, this work intends to carry out a narrative-based review of the literature, conducted using a study of the secondary data developed through a survey of scientific literature databases, and to present the situation of dengue, particularly its distribution in these localities. Our findings from the literature demonstrate the difficulties that managers face in controlling the spread of and planning a response against dengue, pointing to the high cost of the disease for public coffers, rendering the resources that are already limited even scarcer. This can be associated with the different factors that affect the spread of the disease, including ecological, environmental, and social factors. Thus, in order to combat the disease, it is expected that targeted and properly coordinated public policies need to be adopted not only in specific localities, but also globally.

Proceedings of the 5th Asia Dengue Summit

The 5th Asia Dengue Summit, themed "Roll Back Dengue", was held in Singapore from 13 to 15 June 2022. The summit was co-convened by Asia Dengue Voice and Action (ADVA), Global Dengue and Aedes transmitted Diseases Consortium (GDAC), Southeast Asian Ministers of Education Tropical Medicine and Public Health Network (SEAMEO TROPMED), and the Fondation Mérieux (FMx). Dengue experts from academia and research and representatives from the Ministries of Health, Regional and Global World Health Organization (WHO), and International Vaccine Institute (IVI) participated in the three-day summit. With more than 270 speakers and delegates from over 14 countries, 12 symposiums, and 3 full days, the 5th ADS highlighted the growing threat of dengue, shared innovations and strategies for successful dengue control, and emphasized the need for multi-sectoral collaboration to control dengue.

Burden of Postinfectious Symptoms after Acute Dengue, Vietnam

We assessed predominantly pediatric patients in Vietnam with dengue and other febrile illness 3 months after acute illness. Among dengue patients, 47% reported >1 postacute symptom. Most resolved by 3 months, but alopecia and vision problems often persisted. Our findings provide additional evidence on postacute dengue burden and confirm children are affected.

Chronic sequelae complicate convalescence from both dengue and acute viral respiratory illness

Long Covid has raised awareness of the potentially disabling chronic sequelae that afflicts patients after acute viral infection. Similar syndromes of post-infectious sequelae have also been observed after other viral infections such as dengue, but their true prevalence and functional impact remain poorly defined. We prospectively enrolled 209 patients with acute dengue (n = 48; one with severe dengue) and other acute viral respiratory infections (ARI) (n = 161), and followed them up for chronic sequelae up to one year post-enrolment, prior to the onset of the Covid-19 pandemic. Baseline demographics and co-morbidities were balanced between both groups except for gender, with more males in the dengue cohort (63% vs 29%, p<0.001). Except for the first visit, data on symptoms were collected remotely using a purpose-built mobile phone application. Mental health outcomes were evaluated using the validated SF-12v2 Health Survey. Almost all patients (95.8% of dengue and 94.4% of ARI patients) experienced at least one symptom of fatigue, somnolence, headache, concentration impairment or memory impairment within the first week of enrolment. Amongst patients with at least 3-months of follow-up, 18.0% in the dengue cohort and 14.6% in the ARI cohort experienced persistent symptoms. The median month-3 SF-12v2 Mental Component Summary Score was lower in patients who remained symptomatic at 3 months and beyond, compared to those whose symptoms fully resolved (47.7 vs. 56.0, p<0.001), indicating that patients who self-reported persistence of symptoms also experienced functionally worse mental health. No statistically significant difference in age, gender distribution or hospitalisation status was observed between those with and without chronic sequelae. Our findings reveal an under-appreciated burden of post-infection chronic sequelae in dengue and ARI patients. They call for studies to define the pathophysiology of this condition, and determine the efficacy of both vaccines as well as antiviral drugs in preventing such sequelae.

Chronic sequelae after viral infections such dengue have been observed, but their true prevalence and impact remain undefined. We prospectively enrolled a cohort of 209 patients with dengue and acute viral respiratory infections (ARI) and followed them up chronic sequelae for up to one year. 18% of patients in the dengue cohort and 14.6% of patients in the ARI cohort experienced chronic sequelae such as fatigue, somnolence, headache, concentration impairment and memory impairment. Patients who experienced chronic sequelae also had lower month-3 SF-12v2 Mental Component Summary Scores, suggesting that such those who self-reported persistence of symptoms experienced functionally worse mental health. Overall our findings reveal an under-appreciated burden of chronic sequelae in dengue and ARI patients and call for further studies to define the pathophysiology and potential therapeutic options for this condition.

Dengue and COVID-19: two sides of the same coin

BACKGROUND

Many countries in Asia and Latin America are currently facing a double burden of outbreaks due to dengue and COVID-19. Here we discuss the similarities and differences between the two infections so that lessons learnt so far from studying both infections will be helpful in further understanding their immunopathogenesis and to develop therapeutic interventions.

MAIN BODY

Although the entry routes of the SARS-CoV-2 and the dengue virus (DENV) are different, both infections result in a systemic infection, with some similar clinical presentations such as fever, headache, myalgia and gastrointestinal symptoms. However, while dengue is usually associated with a tendency to bleed, development of micro and macrothrombi is a hallmark of severe COVID-19. Apart from the initial similarities in the clinical presentation, there are further similarities between such as risk factors for development of severe illness, cytokine storms, endothelial dysfunction and multi-organ failure. Both infections are characterised by a delayed and impaired type I IFN response and a proinflammatory immune response. Furthermore, while high levels of potent neutralising antibodies are associated with protection, poorly neutralising and cross-reactive antibodies have been proposed to lead to immunopathology by different mechanisms, associated with an exaggerated plasmablast response. The virus specific T cell responses are also shown to be delayed in those who develop severe illness, while varying degrees of endothelial dysfunction leads to increased vascular permeability and coagulation abnormalities.

CONCLUSION

While there are many similarities between dengue and SARS-CoV-2 infection, there are also key differences especially in long-term disease sequelae. Therefore, it would be important to study the parallels between the immunopathogenesis of both infections for development of more effective vaccines and therapeutic interventions.

Dengue and post-infection fatigue: findings from a prospective cohort-the Colombo Dengue Study

BACKGROUND

Previous studies on post-infection fatigue in dengue are few but suggest that up to 25% of dengue patients may suffer from fatigue. This study aimed to evaluate the prevalence and associations of post-infection fatigue in dengue patients compared with non-dengue fever patients.

METHODS

Post-infection fatigue and its demographic and clinical associations were assessed in adult dengue and non-dengue fever patients 2 months after the acute infection in a prospective cohort study in Sri Lanka. Fatigue at 2 months (primary endpoint) was assessed with the fatigue questionnaire as a dichotomous outcome based on a pre-recommended cut-off (score ≥4) and as the total score from the questionnaire (higher score indicates more fatigue).

RESULTS

Of 260 patients, 158 had dengue and, of these, 51 (32%) had fatigue at 2 months. Risk was higher in dengue patients (vs non-dengue; relative risk [RR] 4.93 [95% confidence interval {CI} 2.3 to 10.4]) and more so in female dengue patients (vs male dengue patients; RR 2.45 [95% CI 1.24 to 4.86]). Severe dengue patients had a higher mean fatigue score (p=0.024).

CONCLUSIONS

Post-infection fatigue is an underappreciated burden of this widely prevalent infection. Our findings are useful to triage patients at risk of fatigue for follow-up.

Persistence of symptoms in dengue patients: a clinical cohort study

BACKGROUND

Dengue is commonly considered an acute illness and follows three phases: febrile, critical in some cases and recovery. However, a number of studies have described a continuation of dengue symptoms for weeks or months, extending the recovery phase. Here we evaluate this persistence of dengue symptoms during convalescence.

METHODS

Our clinical cohort study included patients who sought medical services 48 to 144 h from the onset of fever at seven hospitals or ambulatory centers in Morelos, Mexico. Seventy-nine laboratory-confirmed dengue patients were followed up regularly using clinic and/or home visits and telephone calls for as long as symptoms persisted or up to 6 mo.

RESULTS

In total, 55.7% of patients had dengue-related symptoms 1 mo after the onset of fever; pain and dermatological manifestations were the most common persistent symptoms. Prognostic factors for symptom persistence were: ≥4 d of fever (RR 1.72; 95% CI 1.35 to 2.19), platelet count ≤100 000/mm3 (RR 1.20; 95% CI 1.20 to 2.20), petechiae/bruises (RR 1.97; 95% CI 1.56 to 2.48) and abdominal pain/hepatomegaly (RR 1.79; 95% CI 1.41 to 2.28).

CONCLUSIONS

Persistence of dengue symptoms were common in laboratory-confirmed dengue patients. Manifestations related to tissue damage were associated with persistence after 30 d; host characteristics, such as age and health status before infection, were associated with prolonged persistence (>60 d). The burden of dengue may be higher than previously estimated.

Health-Related Quality of Life after Dengue Fever, Morelos, Mexico, 2016-2017

We adapted the EQ-5D-3L questionnaire and visual analog scale to assess health-related quality of life (HRQOL) and persistent symptoms in 79 patients with laboratory-confirmed dengue in Morelos, Mexico. The lowest HRQOLs were 0.53 and 38.1 (febrile phase). Patients recovered baseline HRQOL in ≈2 months.

Assessing the reporting of Dengue, Chikungunya and Zika to the National Surveillance System in Colombia from 2014-2017: A Capture-recapture analysis accounting for misclassification of arboviral diagnostics

BACKGROUND

Chikungunya, dengue, and Zika are three different arboviruses which have similar symptoms and are a major public health issue in Colombia. Despite the mandatory reporting of these arboviruses to the National Surveillance System in Colombia (SIVIGILA), it has been reported that the system captures less than 10% of diagnosed cases in some cities.

METHODOLOGY/PRINCIPAL FINDINGS

To assess the scope and degree of arboviruses reporting in Colombia between 2014-2017, we conducted an observational study of surveillance data using the capture-recapture approach in three Colombian cities. Using healthcare facility registries (capture data) and surveillance-notified cases (recapture data), we estimated the degree of reporting by clinical diagnosis. We fit robust Poisson regressions to identify predictors of reporting and estimated the predicted probability of reporting by disease and year. To account for the potential misclassification of the clinical diagnosis, we used the simulation extrapolation for misclassification (MC-SIMEX) method. A total of 266,549 registries were examined. Overall arboviruses' reporting ranged from 5.3% to 14.7% and varied in magnitude according to age and year of diagnosis. Dengue was the most notified disease (21-70%) followed by Zika (6-45%). The highest reporting rate was seen in 2016, an epidemic year. The MC-SIMEX corrected rates indicated underestimation of the reporting due to the potential misclassification bias.

CONCLUSIONS

These findings reflect challenges on arboviruses' reporting, and therefore, potential challenges on the estimation of arboviral burden in Colombia and other endemic settings with similar surveillance systems.

Resistance exercises improve physical function in chronic Chikungunya fever patients: a randomized controlled trial

BACKGROUND

Chikungunya fever is an arboviral disease, caused by an alphavirus, the Chikungunya virus, characterized by fever and joint pain that is generally disabling in the acute phase and may last from months to years, with the potential to evolve into chronic musculoskeletal symptoms, as polyarthralgia and arthritis, which can lead to significant impairment of physical function. The non-pharmacological treatment is very important for these patients, and resistance exercises may be one rehabilitation option.

AIM

This study aimed to evaluate the efficacy of a resistance exercise protocol on the physical function, pain, and quality of life of patients with chronic Chikungunya fever.

DESIGN

A randomized, controlled, blind trial for the evaluators.

SETTING

Clinic-school of Physical therapy.

POPULATION

Thirty-one patients with Chikungunya fever and musculoskeletal symptoms lasting more than three months, recruited from the Rheumatology outpatient clinic at Clinical Hospital, Federal University of Pernambuco (HC-UFPE).

METHODS

Patients (aged 56±10 years) were randomly assigned into one of two groups: Resistance Exercise Group (REG, N.=15) or Control Group (CG, N.=16). REG performed progressive resistance exercises with elastic bands (24 sessions over 12 weeks). CG only had their symptoms monitored through phone calls, maintaining the usual care treatment. Assessments were taken at baseline and after 6 and 12 weeks of the following: physical function (30-second Chair Stand Test (30-s CST), 4-step Stair Climb Power Test (4SCPT), 40-m Fast-paced Walk Test (40m FPWT), and Disabilities of the Arm, Shoulder, Hand (DASH) questionnaire); pain (VAS and painful joints count); quality of life (Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36]); and Patient Global Impression of Change (PGIC) scale.

RESULTS

There was a reduction of pain (P=0.01; d=-0.83) and an improvement of 30-s CST (P=0.04; d=0.85) in REG participants after 12 weeks. There was no significant change in the domains of SF-36. Nearly 70% of trained patients reported improvement on PGIC.

CONCLUSIONS

Resistance exercises improved physical function in sitting and standing and reduced pain in patients with chronic Chikungunya fever.

CLINICAL REHABILITATION IMPACT

Resistance exercises can be considered as a treatment approach for patients with musculoskeletal disorders in the chronic stage of Chikungunya fever.

Cost of Dengue Illness in Indonesia across Hospital, Ambulatory, and not Medically Attended Settings

Informed decisions concerning emerging technologies against dengue require knowledge about the disease’s economic cost and each stakeholder’s potential benefits from better control. To generate such data for Indonesia, we reviewed recent literature, analyzed expenditure and utilization data from two hospitals and two primary care facilities in Yogyakarta city, and interviewed 67 dengue patients from hospital, ambulatory, and not medically attended settings. We derived the cost of a dengue episode by outcome, setting, and the breakdown by payer. We then calculated aggregate Yogyakarta and national costs and 95% uncertainty intervals (95% UIs). Dengue costs per nonfatal case in hospital, ambulatory, not medically attended, and overall average settings were US$316.24 (95% UI: $242.30–$390.18), US$22.45 (95% UI: $14.12–$30.77), US$7.48 (95% UI: $2.36–$12.60), and US$50.41 (95% UI: $35.75–$65.07), respectively. Costs of nonfatal episodes were borne by the patient’s household (37%), social contributors (relatives and friends, 20%), national health insurance (25%), and other sources (government, charity, and private insurance, 18%). After including fatal cases, the average cost per episode became $90.41 (95% UI: $72.79–$112.35). Indonesia had an estimated 7.535 (95% UI: 1.319–16.513) million dengue episodes in 2017, giving national aggregate costs of $681.26 (95% UI: $232.28–$2,371.56) million. Unlike most previous research that examined only the formal medical sector, this study included the estimated 63% of national dengue episodes that were not medically attended. Also, this study used actual costs, rather than charges, which generally understate dengue’s economic burden in public facilities. Overall, this study found that Indonesia’s aggregate cost of dengue was 73% higher than previously estimated, strengthening the need for effective control.

Evaluation of the Models for Forecasting Dengue in Brazil from 2000 to 2017: An Ecological Time-Series Study

We aimed to evaluate the accuracy of deterministic and stochastic statistical models by means of a protocol developed in a free programming environment for monthly time-series analysis of the incidence of confirmed dengue cases in the states and federal district of Brazil from January 2000 to December 2017. This was an ecological time-series study conducted to evaluate and validate the accuracy of 10 statistical models for predicting the new cases of dengue. Official data on the monthly cases of dengue from January 2000 to December 2016 were used to train the statistical models, while those for the period January-December 2017 were used to test the predictive capacity of the models by considering three forecasting horizons (12, 6, and 3 months). Deterministic models proved to be reliable for predicting dengue in a 12-month forecasting horizon, while stochastic models were reliable for predicting the disease in a 3-month forecasting horizon. We were able to reliably employ models for predicting dengue in the states and federal district of Brazil. Hence, we strongly recommend incorporating these models in state health services for predicting dengue and for decision-making with regard to the advanced planning of interventions before the emergence of epidemics.

Profuse Sweating and Hot Flashes: An Unusual Presentation of Post-Dengue Fatigue Syndrome

The dengue virus is a mosquito-borne flavivirus that causes dengue fever (DF), dengue hemorrhagic fever, and dengue shock syndrome. DF is characterized by fever, headache, arthralgia, retro-orbital pain, and skin rashes. However, some patients with DF develop post-dengue fatigue syndrome (PDFS) following their initial febrile episode. Fatigue is common during the febrile episode of DF; however, PDFS is defined as the presence of a stubborn sense of tiredness that results in a decreased capacity for physical and mental work. PDFS carries a spectrum of musculoskeletal and neurological features. Following the recovery of DF, vasomotor symptoms such as hot flashes, excess sweating, and mood changes are rare. We present the first reported case of PDFS in a young woman in Sri Lanka.

Burden of communicable diseases and cost of illness: Asia pacific region

BACKGROUND

Communicable diseases such as AIDS/HIV, dengue fever, and malaria have a great burden and subsequent economic loss in the Asian region. The purpose of this article is to review the widespread burden of communicable diseases and related health-care burden for the patient in Asia and the Pacific.

AREAS COVERED

In Central Asia, the number of new AIDS cases increased by 29%. It is more endemic in the poor population with variations in the cost of illness. Dengue is prevalent in more than 100 countries, including the Asia-Pacific region. In Southeast Asia, the annual economic burden of dengue fever was between $ 610 and $ 1,384 million, with a per capita cost of $ 1.06 to $ 2.41. Globally, 2.9 billion people are at risk of developing malaria, 90% of whom are residents of the Asia and Pacific region. The annual per capita cost of malaria control ranged from $ 0.11 to $ 39.06 and for elimination from $ 0.18 to $ 27.

EXPERT OPINION

The cost of AIDS, dengue, and malaria varies from country to country due to different health-care systems. The literature review has shown that the cost of dengue disease and malaria is poorly documented.

Productivity costs from a dengue episode in Asia: a systematic literature review

Background

Dengue is a mosquito-borne viral infection which has been estimated to cause a global economic burden of US$8.9 billion per year. 40% of this estimate was due to what are known as productivity costs (the costs associated with productivity loss from both paid and unpaid work that results from illness, treatment or premature death). Although productivity costs account for a significant proportion of the estimated economic burden of dengue, the methods used to calculate them are often very variable within health economic studies. The aim of this review was to systematically examine the current estimates of the productivity costs associated with dengue episodes in Asia and to increase awareness surrounding how productivity costs are estimated.

Method

We searched PubMed and Web of Knowledge without date and language restrictions using terms related to dengue and cost and economics burden. The titles and abstracts of publications related to Asia were screened to identify relevant studies. The reported productivity losses and costs of non-fatal and fatal dengue episodes were then described and compared. Costs were adjusted for inflation to 2017 prices.

Results

We reviewed 33 relevant articles, of which 20 studies reported the productivity losses, and 31 studies reported productivity costs. The productivity costs varied between US$6.7–1445.9 and US$3.8–1332 for hospitalized and outpatient non-fatal episodes, respectively. The productivity cost associated with fatal dengue episodes varied between US$12,035-1,453,237. A large degree of this variation was due to the range of different countries being investigated and their corresponding economic status. However, estimates for a given country still showed notable variation.

Conclusion

We found that the estimated productivity costs associated with dengue episodes in Asia are notable. However, owing to the significant variation in methodology and approaches applied, the reported productivity costs of dengue episodes were often not directly comparable across studies. More consistent and transparent methodology regarding the estimation of productivity costs would help the estimates of the economic burden of dengue be more accurate and comparable across studies.

A review of the economic evidence of Aedes-borne arboviruses and Aedes-borne arboviral disease prevention and control strategies

Introduction: Aedes-borne arboviruses contributes substantially to the disease and cost burden.Areas covered: We performed a systematic review of the economic evidence surrounding aedes-borne arboviruses and strategies to prevent and control these diseases to inform disease control policy decisions and research directions. We searched four databases covering an 18-year period (2000-2018) to identify arboviral disease-related cost of illness studies, cost studies of vector control and prevention strategies, cost-effectiveness analyses and cost-benefit analyses. We identified 74 published studies that revealed substantial global total costs in yellow fever virus and dengue virus ranging from 2.1 to 57.3 billion USD. Cost studies of vector control and surveillance programs are limited, but a few studies found that costs of vector control programs ranged from 5.62 to 73.5 million USD. Cost-effectiveness evidence was limited across Aedes-borne diseases, but generally found targeted dengue vaccination programs cost-effective. This review revealed insufficient economic evidence for vaccine introduction and implementation of surveillance and vector control programs.Expert opinion: Evidence of the economic burden of aedes-borne arboviruses and the economic impact of strategies for arboviral disease prevention and control is critical to inform policy decisions and to secure continued financial support for these preventive and control measures.

Assessment of Prolonged Dengue Virus Infection in Dermal Fibroblasts and Hair-Follicle Dermal Papilla Cells

Dengue virus (DENV)-mediated hair loss is one of the post-dengue fatigue syndromes and its pathophysiology remains unknown. Whether long-term or persistent infection with DENV in the scalp results in hair loss is unclear. In this study, we cultured human dermal fibroblasts (WS1 cells) and primary human hair-follicle dermal papilla cells (HFDPCs) in the long term with DENV-2 infection. The production of virion, the expression of inflammatory and anti-virus genes, and their signaling transduction activity in the infected cells were analyzed. DENV-2 NS3 protein and DENV-2 5′ UTR RNA were detected in fibroblasts and HFDPCs that were subjected to long-term infection with DENV-2 for 33 days. A significant amount of DENV-2 virion was produced by both WS1 cells and HFDPCs in the first two days of acute infection. The virion was also detected in WS1 cells that were infected in the long term, but HFDPCs failed to produce DENV-2 after long-term culture. Type I and type III interferons, and inflammatory cytokines were highly expressed in the acute phase of DENV infection in HFPDC and WS1 cells. However, in the long-term cultured cells, modest levels of anti-viral protein genes were expressed and we observed reduced signaling activity, which was correlated with the level of virus production changes. Long-term infection of DENV-2 downregulated the expression of hair growth regulatory factors, such as Rip1, Wnt1, and Wnt4. This in vitro study shows that the long-term infection with DENV-2 in dermal fibroblasts and dermal papilla cells may be involved with the prolonged-DENV-infection-mediated hair loss of post-dengue fatigue syndrome. However, direct evidence for viral replication in the human hair of a dengue victim or animal infection model is required.

The Global Expansion of Dengue: How Aedes aegypti Mosquitoes Enabled the First Pandemic Arbovirus

Dengue is an emerging viral disease principally transmitted by the Aedes (Stegomyia) aegypti mosquito. It is one of the fastest-growing global infectious diseases, with 100-400 million new infections a year, and is now entrenched in a growing number of tropical megacities. Behind this rapid rise is the simple adaptation of Ae. aegypti to a new entomological niche carved out by human habitation. This review describes the expansion of dengue and explores how key changes in the ecology of Ae. aegypti allowed it to become a successful invasive species and highly efficient disease vector. We argue that characterizing geographic heterogeneity in mosquito bionomics will be a key research priority that will enable us to better understand future dengue risk and design control strategies to reverse its global spread.

Impact of a Nonfatal Dengue Episode on Disability-Adjusted Life Years: A Systematic Analysis

As dengue causes about 4,000 symptomatic nonfatal episodes for every dengue death globally, quantitative disability assessments are critical to assess the burden of dengue and the cost-effectiveness of dengue control interventions. This systematic analysis of disability or quality of life lost from a symptomatic nonfatal dengue episode combined a systematic literature review, statistical modeling, and probabilistic sensitivity analyses. We conceptualized a dengue episode as having two phases: acute and persistent symptoms. Our estimates for the acute phase, consisting of onset and recovery periods and defined as the first 20 days (0.054 year), were based on literature review. We searched PubMed, POPLINE, EconLit, Google Scholar, scientific conferences, and other sources, for “dengue” plus “quality of life” or related terms. From 4,322 initial entries, six met our criteria (original studies with empirical data). The median disability-adjusted life year (DALY) burden for the acute phase was 0.011 (95% certainty interval [CI]: 0.006–0.015) for ambulatory episodes, 0.015 (CI: 0.010–0.020) for hospitalized episodes, and 0.012 (CI: 0.006–0.019) overall. Using literature reviews about persistent dengue, we estimated that 34% of episodes experienced persistent symptoms with a median duration of symptoms of 0.087 (CI: 0.040–0.359) year, which resulted in median DALYs of 0.019 (CI: 0.008–0.082). Thus, the overall median DALY burden was 0.031 (CI: 0.017–0.092) for ambulatory episodes, 0.035 (CI: 0.024–0.096) for hospitalized episodes, and 0.032 (CI: 0.018–0.093) overall. Our dengue-specific burden of a dengue episode was 2.1 times the 2013 Global Burden of Disease estimate. These literature-based estimates provide an empirical summary for policy and cost-effectiveness analyses.

The Uncertainty Surrounding the Burden of Post-acute Consequences of Dengue Infection

Post-acute consequences currently form a significant component of the dengue disability-adjusted life year (DALY) burden estimates. However, there is considerable uncertainty regarding the incidence, duration, and severity of these symptoms. Further research is needed to more accurately estimate the health and economic burden of these dengue manifestations.

Economic impact of dengue in Mexico considering reported cases for 2012 to 2016

Background

Given that dengue disease is growing and may progress to dengue hemorrhagic fever (DHF), data on economic cost and disease burden are important. However, data for Mexico are limited.

Methodology/Principal findings

Burden of dengue fever (DF) and DHF in Mexico was assessed using official databases for epidemiological information, disabilities weights from Shepard et al, the reported number of cases and deaths, and costs. Overall costs of dengue were summed from direct medical costs to the health system, cost of dengue to the patient (out-of-pocket expenses [medical and non-medical], indirect costs [loss of earnings, patient and/or caregiver]), and other government expenditures on prevention/surveillance. The first three components, calculated as costs per case by a micro-costing approach (PAATI; program, actions, activities, tasks, inputs), were scaled up to overall cost using epidemiology data from official databases. PAATI was used to calculate cost of vector control and prevention, education, and epidemiological surveillance, based on an expert consensus and normative construction of an ideal scenario.

Disability-adjusted life years (DALYs) for Mexico in 2016 were calculated to be 2283.46 (1.87 per 100,000 inhabitants). Overall economic impact of dengue in Mexico for 2012 was US$144 million, of which US$44 million corresponded to direct medical costs and US$5 million to the costs from the patient’s perspective. The estimated cost of prevention/surveillance was calculated with information provided by federal government to be US$95 million. The overall economic impact of DF and DHF showed an increase in 2013 to US$161 million and a decrease to US$133, US$131 and US$130 million in 2014, 2015 and 2016, respectively.

Conclusions/Significance

The medical and economic impact of dengue were in agreement with other international studies, and highlight the need to include governmental expenditure for prevention/surveillance in overall cost analyses given the high economic impact of these, increasing the necessity to evaluate its effectiveness.

Dengue fever is caused by a flavivirus transmitted predominantly by the mosquito Aedes aegypti. Infection causes a broad spectrum of clinical signs and symptoms, from mild disease, such as dengue fever to a life threatening form known as dengue hemorrhagic fever. The disease is widespread in tropical regions. Measures such as vector control can slow the spread of infection, and most countries where the disease is endemic, Mexico included, have programs in place to this end. However, faced with other health issues that also require attention, it is important to quantify the suffering caused by dengue and also its economic costs. In this study, we aimed to produce detailed figures for Mexico to complement and refine those available from international studies. Such information will help guide how the money budgeted for health in dengue is spent.

The Estimates of the Health and Economic Burden of Dengue in Vietnam

Dengue has been estimated to cause a substantial health and economic burden in Vietnam. The most recent studies have estimated that it is responsible for 39884 disability-adjusted life years (DALYs) annually, representing an economic burden of US$94.87 million per year (in 2016 prices). However, there are alternative burden estimates that are notably lower. This variation is predominantly due to differences in how the number of symptomatic dengue cases is estimated. Understanding the methodology of these burden calculations is vital when interpreting health economic analyses of dengue. This review aims to provide an overview of the health and economic burden estimates of dengue in Vietnam. We also highlight important research gaps for future studies.

Economic impact of dengue fever in Latin America and the Caribbean: a systematic review

OBJECTIVES

To assess the economic impact of dengue in Latin America and the Caribbean using a systematic review that includes studies not previously considered by other reviews.

METHODS

Cochrane methodology was used to conduct a systematic review of the cost of dengue in Latin America. PubMed Central, EMBASE, and the Biblioteca Virtual en Salud-which includes scientific, peer-reviewed journals not indexed by other databases-were searched from inception through August 2016. All articles that reported cost of illness data for countries in Latin America were included. Included studies underwent a methodological appraisal using a seven-question instrument designed for cost of illness studies. Extracted data were direct and indirect costs for outpatient and hospitalized cases and total cost of the disease. Values were adjusted to 2015 US dollars using the consumer price index.

RESULTS

From a total of 848 initial references, 17 studies were included, mainly from Brazil, Colombia, Cuba, Mexico, and Puerto Rico; costs were available for 39 countries. The methodological appraisal showed that 70% of the studies met more than 70% of the evaluated items. The main economic impact of dengue was due to productivity costs. Average annual cost was more than US$ 3 billion. Direct costs represented over 70% of the total share for hospitalized cases. For outpatients, direct medical costs were low, but social costs were significant since indirect costs may account for up to 80% of the total cost.

CONCLUSIONS

Dengue fever has a significant economic impact in Latin America. It is essential to develop new public health interventions, such as dengue vaccination, to decrease the propagation of the disease and its total cost.

Clinical, laboratory, and demographic determinants of hospitalization due to dengue in 7613 patients: A retrospective study based on hierarchical models

In Brazil, the incidence of hospitalization due to dengue, as an indicator of severity, has drastically increased since 1998. The objective of our study was to identify risk factors associated with subsequent hospitalization related to dengue. We analyzed 7613 dengue confirmed via serology (ELISA), non-structural protein 1, or polymerase chain reaction amplification. We used a hierarchical framework to generate a multivariate logistic regression based on a variety of risk variables. This was followed by multiple statistical analyses to assess hierarchical model accuracy, variance, goodness of fit, and whether or not this model reliably represented the population. The final model, which included age, sex, ethnicity, previous dengue infection, hemorrhagic manifestations, plasma leakage, and organ failure, showed that all measured parameters, with the exception of previous dengue, were statistically significant. The presence of organ failure was associated with the highest risk of subsequent dengue hospitalization (OR=5·75; CI=3·53-9·37). Therefore, plasma leakage and organ failure were the main indicators of hospitalization due to dengue, although other variables of minor importance should also be considered to refer dengue patients to hospital treatment, which may lead to a reduction in avoidable deaths as well as costs related to dengue.

A multi-country study of the economic burden of dengue fever: Vietnam, Thailand, and Colombia

Background

Dengue fever is a major public health concern in many parts of the tropics and subtropics. The first dengue vaccine has already been licensed in six countries. Given the growing interests in the effective use of the vaccine, it is critical to understand the economic burden of dengue fever to guide decision-makers in setting health policy priorities.

Methods/Principal findings

A standardized cost-of-illness study was conducted in three dengue endemic countries: Vietnam, Thailand, and Colombia. In order to capture all costs during the entire period of illness, patients were tested with rapid diagnostic tests on the first day of their clinical visits, and multiple interviews were scheduled until the patients recovered from the current illness. Various cost items were collected such as direct medical and non-medical costs, indirect costs, and non-out-of-pocket costs. In addition, socio-economic factors affecting disease severity were also identified by adopting a logit model. We found that total cost per episode ranges from $141 to $385 for inpatient and from $40 to $158 outpatient, with Colombia having the highest and Thailand having the lowest. The percentage of the private economic burden of dengue fever was highest in the low-income group and lowest in the high-income group. The logit analyses showed that early treatment, higher education, and better knowledge of dengue disease would reduce the probability of developing more severe illness.

Conclusions/Significance

The cost of dengue fever is substantial in the three dengue endemic countries. Our study findings can be used to consider accelerated introduction of vaccines into the public and private sector programs and prioritize alternative health interventions among competing health problems. In addition, a community would be better off by propagating the socio-economic factors identified in this study, which may prevent its members from developing severe illness in the long run.

Dengue fever has been prevalent in South-East Asia and South America. Despite the increase of dengue fever cases, there continues to be a lack of economic assessment partly due to the absence of vaccines until recent times. Many of the previous economic burden studies for dengue fever were not standardized, making them difficult to compare. We implemented the standardized economic burden survey for dengue fever in a multi-country setting: Vietnam, Thailand, and Colombia. We found that the economic burden of dengue fever is substantial in all three dengue endemic countries. Our study also identified socio-economic factors which are related to the probability of experiencing severe illness. The first live attenuated, tetravalent dengue vaccine (CYD-TDV) has been already licensed in some dengue-endemic countries. As three countries will soon face decisions on whether and how to incorporate current and future vaccine candidates within their budget constraints, the updated economic burden estimates can be used to develop sustainable financing plans.

Prospective study of patients with persistent symptoms of dengue in Brazil

Dengue is an arboviral infection clinically recognized as an acute and self-limited disease. Persistence of dengue symptoms is known, but it has been little studied. The aim of this study was to characterize persistent symptoms in 113 patients with dengue followed up clinically and by laboratory testing at a tertiary hospital. Symptoms that persisted for more than 14 days were observed in 61 (54.0%) patients, and six (6.2%) of them had symptoms for 6 months or more. The persistent symptoms identified were myalgia, weakness, hair loss, memory loss, reduced resistance to physical effort, headache, reasoning problems, arthralgia, sleepiness- and emotional lability. The progression to persistent symptoms was significantly associated with hospitalization, older age, more severe disease, the presence of bleeding and comorbidities upon univariate analysis. Upon multivariate analysis, the presence of persistent symptoms continued to be significantly associated only with increased age and dengue with warning signs. The platelet count during the acute phase of the disease was significantly lower in the group with persistent symptoms. In conclusion, the frequency of progression to persistent symptoms in dengue is relevant in patients seen at a tertiary hospital and the persistence of symptoms is more common in patients with dengue with warning signs.

Disease Burden of Dengue in the Philippines: Adjusting for Underreporting by Comparing Active and Passive Dengue Surveillance in Punta Princesa, Cebu City

AbstractDengue virus (DENV) is a serious threat to public health. Having reliable estimates of the burden of dengue is important to inform policy and research, but surveillance systems are not designed to capture all symptomatic DENV infections. We derived the rate of reporting of dengue by comparing active surveillance of symptomatic DENV infections in a prospective community-based seroepidemiological cohort study (N = 1008) of acute febrile illness in Punta Princesa, Cebu City, Philippines, with passive surveillance data from the Cebu City Health Department. Febrile episodes detected in a weekly follow-up of participants were tested for serotype-specific DENV by hemi-nested reverse transcription-polymerase chain reaction (nested RT-PCR) and acute/convalescent blood samples tested by dengue IgM/IgG enzyme immunoassay. We estimated the burden of dengue in the Philippines in disability-adjusted life years (DALYs), and conducted a probabilistic sensitivity analysis using Monte-Carlo simulations to address uncertainty. The results showed a 21% cumulative reporting rate of symptomatic DENV infections, equivalent to an expansion factor of 4.7 (95% certainty level [CL]: 2.2-15.1). Based on surveillance data in the Philippines for 2010-2014, we estimated 794,255 annual dengue episodes (95% CL: 463,000-2,076,000) and a disease burden of 535 (95% CL: 380-994) DALYs per million population using age weights and time discounting and 997 (95% CL: 681-1,871) DALYs per million population without age and time adjustments. Dengue imposes a substantial burden in the Philippines; almost 10 times higher than estimated for rabies, about twice the burden of intestinal fluke infections, and about 10% of the burden of tuberculosis. Our estimates should inform policy makers and raise awareness among the public.

Disease and economic burdens of dengue

The burden of dengue is large and growing. More than half of the global population lives in areas with risk of dengue transmission. Uncertainty in burden estimates, however, challenges policy makers' ability to set priorities, allocate resources, and plan for interventions. In this report, the first in a Series on dengue, we explore the estimations of disease and economic burdens of dengue, and the major estimation challenges, limitations, and sources of uncertainty. We also reflect on opportunities to remedy these deficiencies. Point estimates of apparent dengue infections vary widely, although the confidence intervals of these estimates overlap. Cost estimates include different items, are mostly based on a single year of data, use different monetary references, are calculated from different perspectives, and are difficult to compare. Comprehensive estimates that decompose the cost by different stakeholders (as proposed in our framework), that consider the cost of epidemic years, and that account for productivity and tourism losses, are scarce. On the basis of these estimates, we propose the most comprehensive framework for estimating the economic burden of dengue in any region, differentiated by four very different domains of cost items and by three potential stakeholders who bear the costs. This framework can inform future estimations of the economic burden of dengue and generate demand for additional routine administrative data collection, or for systematic incorporation of additional questions in nationally representative surveys in dengue-endemic countries. Furthermore, scholars could use the framework to guide scenario simulations that consider ranges of possible values for cost items for which data are not yet available. Results would be valuable to policy makers and would also raise awareness among communities, potentially improving dengue control efforts.

Long-term sequelae of chikungunya virus disease: A systematic review

BACKGROUND

The acute phase of chikungunya is well documented; less so are its long-term effects. This systematic literature review provides an overview of the currently available data.

METHODS

We performed an electronic search in PubMed/Medline and checked reference lists. We included studies in English on long-term sequelae of chikungunya in adults and on long-term sequelae of congenital infection from 2000 to 2016. Case reports, reviews and studies with a follow-up shorter than 6 weeks were excluded.

RESULTS

In total, 37 studies were included; with follow-up periods ranging from 1.5 to 72 months. Most studies were questionnaire-based studies only, in which clinical diagnoses such as arthritis, alopecia and depression were mostly recorded without professional verification. Persisting arthralgia/arthritis (arthralgia/joint stiffness plus joint swelling) was the most frequent problem encountered. Further frequently mentioned sequelae were alopecia and depression. Quality of life was reduced in many for months to years after the acute phase of chikungunya. Female gender, older age, some co-morbidities and the severity of the acute phase were associated with persistent arthralgia. Congenital infection was associated with neurocognitive dysfunctioning in early childhood.

CONCLUSION

Chikungunya leads to (self-perceived) long-term sequelae in a considerable proportion of patients, impacting significantly on quality of life. Long-term chikungunya sequelae must be taken into account when dealing with this disease because of its important effect on public and individual health. Prospective large-scale, long-term studies with objective assessment of signs and symptoms attributed to the disease are needed to optimally quantify and qualify these problems.

The global economic burden of dengue: a systematic analysis

BACKGROUND

Dengue is a serious global burden. Unreported and unrecognised apparent dengue virus infections make it difficult to estimate the true extent of dengue and current estimates of the incidence and costs of dengue have substantial uncertainty. Objective, systematic, comparable measures of dengue burden are needed to track health progress, assess the application and financing of emerging preventive and control strategies, and inform health policy. We estimated the global economic burden of dengue by country and super-region (groups of epidemiologically similar countries).

METHODS

We used the latest dengue incidence estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease Study 2013 and several other data sources to assess the economic burden of symptomatic dengue cases in the 141 countries and territories with active dengue transmission. From the scientific literature and regressions, we estimated cases and costs by setting, including the non-medical setting, for all countries and territories.

FINDINGS

Our global estimates suggest that in 2013 there were a total of 58·40 million symptomatic dengue virus infections (95% uncertainty interval [95% UI] 24 million-122 million), including 13 586 fatal cases (95% UI 4200-34 700), and that the total annual global cost of dengue illness was US$8·9 billion (95% UI 3·7 billion-19·7 billion). The global distribution of dengue cases is 18% admitted to hospital, 48% ambulatory, and 34% non-medical.

INTERPRETATION

The global cost of dengue is substantial and, if control strategies could reduce dengue appreciably, billions of dollars could be saved globally. In estimating dengue costs by country and setting, this study contributes to the needs of policy makers, donors, developers, and researchers for economic assessments of dengue interventions, particularly with the licensure of the first dengue vaccine and promising developments in other technologies.

FUNDING

Sanofi Pasteur.