Dengue Outcomes Research Articles

Behavioural Response to a Sudden Health Risk: Dengue and Educational Outcomes in Colombia

Epidemics tend to have a debilitating influence on the lives of directly afflicted families. However, the presence of an epidemic can also change the behaviour and outcomes of those not directly affected. This paper makes use of a short, sharp, unexpected epidemic to examine the behavioural response of the public to a sudden shift in the perceived risk to one’s health and mortality. Our analysis finds that unafflicted school students change their behaviour substantially, affecting important life outcomes. In particular, we find that between 1.9 and 4.7 fewer students, out of a typical cohort of 47 pupils, sit their school leaving examination for every additional 10 cases of severe Dengue per 10 000 inhabitants in a municipality. We rule out several possible mechanisms, leaving an increase in the salience of the disease’s risks as a plausible explanation for our findings.

Diabetic patients suffering dengue are at risk for development of dengue shock syndrome/severe dengue: Emphasizing the impacts of co-existing comorbidity(ies) and glycemic control on dengue severity.

The impact of type 2 diabetes mellitus (DM2) on clinical severity of dengue has not been fully understood. We aimed to assess risk factors for dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS) and severe dengue (SD) (defined based on the World Health Organization 1997 and 2009 dengue classifications), and additionally identify, among DM2 patients, who are at risk for developing DHF/DSS and severe dengue. A retrospective analysis of dengue patients diagnosed between 2002 and 2010. Risk factors for development of DHF/DSS/SD were identified using multivariate analysis. To elucidate the impacts of coexisting comorbidity(ies) (i.e., hypertension, chronic kidney disease, old stroke, and/or ischemic heart disease) and glycemic control on clinical outcomes of dengue in DM2 patients, the overall DM2 patients and stratified DM2 patients (HbA1c<7% vs. HbA1c≧7%), with or without comorbidity(ies), were separately compared to controls (patients without any morbidity). Of 767 (146 DM2 and 621 controls) included patients, 1.4% suffered DSS and 3.3% SD. While DM2 was an independent risk factor for DSS (adjusted odds ratio [AOR]=7.473; 95% confidence interval [CI]=2.221-25.146) and SD (AOR=6.207; 95% CI=2.464-15.636), only DM2 patients with additional comorbidity(ies) and suboptimal glycemic control (HbA1c≧7%) had significantly higher incidences of non-shock DHF (60.8% vs. 29%), DSS (8.7% vs. 0.8%) and SD (34.8% vs. 1.1%). These data could help narrow down the number of targets in the triage for risky DM2 dengue patients to those with suboptimal glycemic control and co-existing comorbidity(ies).

Clinical profile and outcome of dengue in children admitted in pediatric intensive care unit in a tertiary center in South India

Background: As dengue being a tropical infection presenting with varying degrees of severity of illness in Indian children, present study is aimed at studying the clinical profile, outcome, predictors for mortality of moderate and severe dengue cases admitted to PICU in a tertiary care center in South India. Methods: It is a retrospective observational study. All patients admitted in PICU from April 2016 to March 2017 were included in the study. Patients were classified based on National Vector Borne Disease Control Program (NVBDP). Clinical characteristics, laboratory parameters, complications, outcome and predictors for mortality were studied. Results: All 58 seropositive dengue cases admitted were included. Most common presenting symptoms were fever in 58 (100%), vomiting in 33 (56.8%) and abdomen pain in 19 (32.7%). Among severe dengue, expanded dengue syndrome was present in 10 (30%), expanded dengue syndrome with shock was present in 10 (30%), significant hemorrhage with shock in 2 (6%), hemorrhage without shock in 1(3%) and combination of expanded dengue syndrome with hemorrhage and shock in 10 (30%).Pleural effusion was present in 38 (65.5%) and ascites in 18(31%) children. Among severe dengue,12(36.3%) received invasive mechanical ventilation,8(24%) received inotropes,19(57.5%) received steroids and 7 (21%) had abdomen compartment syndrome requiring drainage of ascites. Conclusion: Significantly more number of children who died received ventilator support and inotropes. Commonest cause of death is catecholamine resistant shock. There is no major adverse effect of steroids when used in severe dengue.

Impact of resuscitation with 20% versus 5% albumin in outcome of severe dengue: A prospective observational study

Background : Severe dengue is characterized by severe vascular leakage and abnormal haemostasis which can lead to mortality. As per exciting guidelines fluid resuscitation is recognised as the critical therapeutic intervention; however these guidelines are more empirical than evidence based. Methods : This was a prospective observational study (June 2016 to august 2017), conducted in a tertiary care intensive care unit. Children aged between one month and 18 years with diagnosis of severe dengue were categorized to receive either 20%A or 5%A, in addition to routine fluid resuscitation with crystalloids as per WHO guidelines. Children admitted between June 2016 to August2017, were allocated to receive 20%A (group A) during first 6 month (June 2016 to December 2016) and 5%A (group B) during next 6 month. Arterial blood lactates were measured before and after albumin transfusion and lactate clearance were calculated using the formula (Lactate before - lactate after)/lactate before (%)(mill moles/ liter) . Children were followed up to recovery or mortality. The primary outcome was lactate clearance and the secondary outcome variables were length of hospital stay, duration of mechanical ventilation, fluid overload, mortality and inotrope requirement, which were compared between the two groups. Results : A total of 90 children with 45 in each group were enrolled in the study. The mean lactate clearance in 20%A group was 43.3±17.75% (95% CI: 33.5-53.17) and 5%A group was 19.46±19.0% (95% CI: 8.8 -30.0). This difference was found to be statistically significant (p value=0.001).The mean hospital stay was 129.5±42.1 hours (95%CI: 106.1-152.9) and 162.73±57.2 (95%CI: 131-194.4) in the 20%A and 5%A groups respectively (p value=0.081),and the net fluid overload in 20%A was 133.6±119.8ml/kg (95%CI: 67.2 -199.9) and in the 5%A group was 162.3±96.8ml/kg (95%CI: 108.7-215.9) (p value=0.47), but both were statistically not significant. The need of inotrope requirement between two groups was statistically not significant (p value=0.5). The need of ventilation and mortality (n=1) could not be statistically determined because of inadequate data. Conclusion : Children treated with 20%A had better lactate clearance and relatively lesser fluid overload when compared to 5%A. Since lactate clearance is a viable surrogate marker of resuscitation adequacy 20%A can be considered superior to 5%A as per our study for resuscitation of severe dengue cases. However, randomised control trials with larger sample size are warranted to confirm the advantage of 20%A over 5%A.

Symptomatic dengue infection during pregnancy and the risk of stillbirth in Brazil, 2006–12: a matched case-control study

Maternal infections during pregnancy can increase the risk of fetal death. Dengue infection is common, but little is known about its role in fetal mortality. We aimed to investigate the association between symptomatic dengue infection during pregnancy and fetal death. We did a nested case-control study using obstetrician-collected data from the Brazilian livebirth information system (SINASC), the mortality information system (SIM), and the national reportable disease information system (SINAN). We identified all pregnancies ending in stillbirth and a random sample of livebirths between Jan 1, 2006, and Dec 31, 2012. We did linkage to determine which mothers were diagnosed with dengue infection during pregnancy. By use of stillbirths as cases and a sample of matched livebirths as a control, we calculated matched odds ratios (mORs) using conditional logistic regression adjusted for maternal age and education. 275 (0·2%) of 162 188 women who had stillbirths and 1507 (0·1%) of 1 586 105 women who had livebirths were diagnosed with dengue infection during pregnancy. Symptomatic dengue infection during pregnancy almost doubled the odds of fetal death (mOR 1·9, 95% CI 1·6-2·2). The increase in risk was similar when analyses were restricted to laboratory-confirmed cases of dengue infection (1·8, 1·4-2·4). Severe dengue infection increased the risk of fetal death by about five times (4·9, 2·3-10·2). Symptomatic dengue infection during pregnancy is associated with an increased risk of fetal death. We recommend further epidemiological and biological studies of the association between dengue and poor birth outcomes to measure the burden of subclinical infections and elucidate pathological mechanisms. Brazilian National Council for Scientific and Technological Development, Horizon 2020.

Management of dengue in Australian travellers: a retrospective multicentre analysis.

To describe the epidemiology, clinical and laboratory features and outcomes of dengue in returned Australian travellers, applying the revised WHO dengue classification (2009) to this population. Retrospective case series analysis of confirmed dengue cases hospitalised at one of four Australian tertiary hospitals, January 2012 - May 2015. Clinical features, laboratory findings and outcomes of patients with dengue; dengue classification according to 2009 WHO guidelines. 208 hospitalised patients (median age, 32 years; range, 4-76 years) were included in the study. Dengue was most frequently acquired in Indonesia (94 patients, 45%) and Thailand (40, 19%). The most common clinical features were fever (98% of patients) and headache (76%). 84 patients (40%) met the WHO criteria for dengue with warning signs, and one the criteria for severe dengue; the most common warning signs were mucosal bleeding (44 patients, 21%) and abdominal pain (43, 21%). Leukopenia (176 patients, 85%), thrombocytopenia (133, 64%), and elevated liver enzyme levels (154, 76%) were the most common laboratory findings. 46 patients (22%) had serological evidence of previous exposure to dengue virus. WHO guidelines were documented as a management benchmark in ten cases (5%); 46 patients (22%) received non-steroidal anti-inflammatory drugs (NSAIDs). A significant proportion of returning Australian travellers hospitalised for dengue have unrecognised warning signs of severe disease. Many received NSAIDs, which can increase the risk of haemorrhage in dengue. As travel to Asia from Australia continues to increase, it is vital for averting serious outcomes that clinicians can recognise and manage dengue.

Clinico-epidemiological profile of dengue cases in a Medical College Hospital, Bengaluru, Karnataka, India

Background: Medical college hospital being a tertiary care center receives a significant number of dengue cases from within and outside the catchment area and provides a good opportunity to study the clinical and epidemiological features of dengue infection, its prognosis and outcome so as to institute prompt preventive and control measures. The objective was to describe the clinico-epidemiological features of dengue cases admitted to pediatric ward at a Medical College Hospital, Bengaluru, Karnataka, India.Methods: Cross-sectional study of 140 cases positive for NS1Ag, IgM and/or IgG by dengue rapid immuno-chromatographic card test, admitted in pediatric ward during June to August 2013 at Rajarajeswari Medical College and Hospital.Results: Majority of the patients were from rural area. Fever was present in all 140 cases. Vomiting followed by headache were the common presenting symptoms. Of the 140, 50% cases were classified as dengue fever without warning signs, 46.4% as dengue fever with warning signs and 3.6% as severe dengue. Thrombocytopenia was present in 77.1%, leucopenia in 47.9%, and raised haematocrit in 52.1% of cases. Mortality rate was 0.71%.Conclusions: Children above 5 years of age were most commonly affected age group. About 5 (3.6%) of the patients belonged to severe dengue category according to revised WHO Dengue Case Classification.

Clinical profile and outcome of dengue among hospitalized children - a single centre prospective study

Introduction: Dengue is the most rapidly spreading mosquito-borne viral disease in the world.In India, there is increased proportion of Dengue cases with severe disease. Early recognition and prompt initiation of appropriate treatment are vital to reduce disease related morbidity and mortality. Objective: To study the clinical profile and outcome of hospitalized dengue fever cases in children during outbreaks. Methods: This is an observational prospective study conducted at tertiary care hospital. All children who presented with clinical features of dengue & dengue serology positive children were included in the study. Results: A total of 185 children diagnosed to have dengue fever were admitted in the hospital during the study period. The cases were classified according to WHO protocol as Dengue without warning sign (48.1%), Dengue with warning signs (27%) and severe dengue (24.8%). All the children had fever as the presenting complaint. The other predominant symptoms observed were vomiting (61.6%), abdominal pain (50.2%), rashes (30.2%), myalgia (24.3%), and bleeding manifestation (16.2%). The other significant findings noted were Hepatomegaly (52.4%), Ascites (47.01%), and pleural effusion (41%). Gallbladder wall thickness (80.4%) was the most common radiological abnormality. Mortality in this study was 1.08%. Conclusion: Children in the age group of 5-15 years were most commonly affected. Fever, Persistent vomiting, abdominal pain, Hepatomegaly, pleural effusion, were predominant presenting symptoms and signs. Early recognition, precise assessment and appropriate treatment with the help of WHO revised classification and management guidelines have reduced the mortality.

English

English

Patterns of medication use and factors associated with antibiotic use among adult fever patients at Singapore primary care clinics.

BackgroundAntimicrobial resistance is a public health problem of global importance. In Singapore, much focus has been given to antibiotic usage patterns in hospital settings. Data on antibiotic use in primary care is lacking. We describe antibiotic usage patterns and assess factors contributing to antibiotic usage among adults presenting with acute febrile illness (AFI) in primary care settings in Singapore.MethodsWe analyzed data from the Early Dengue infection and outcome study. Adults with AFI presenting at 5 Singapore polyclinics were included. We used multivariable logistic regression to assess demographic, clinical and laboratory factors associated with antibiotic usage among adults with AFI.ResultsBetween December 2007 and February 2013, 1884 adult AFI patients were enrolled. Overall, 16% of adult AFI patients reported antibiotic use. We observed a rise in the use of over-the-counter medications in late 2009 and a decrease in antibiotic use during 2010, possibly related to the outbreak of pandemic influenza A H1N1 virus. After adjusting for age, gender, polyclinic and year of enrolment, the following factors were associated with higher odds of antibiotic use: living in landed property (compared to public housing) (OR = 1.73; 95% CI: 1.06–2.80); body mass index (BMI) <18.5 (OR = 1.87; 95% CI: 1.19–2.93); elevated white blood cell (WBC) count (OR = 1.98; 95% CI: 1.42–2.78); and persistence of initial symptoms at 2–3 days follow-up with OR (95% CI) for categories of 1, 2, 3, and ≥4 persisting symptoms being 2.00 (1.38–2.92), 2.67 (1.80–3.97), 4.26 (2.73–6.64), and 2.79 (1.84–4.24) respectively.ConclusionsOur study provides insights on antibiotic usage among adult patients presenting to primary care clinics with febrile illness, and suggests that high socio-economic status, and risk factors of a severe illness, that is, low BMI and persistence of initial symptoms, are associated with higher antibiotic use. Further work to understand trends of antibiotic usage in both private and public primary care clinics, and factors that influence patient expectation and physician prescribing of antibiotics is important.

Characteristics of acute febrile illness and determinants of illness recovery among adults presenting to Singapore primary care clinics.

BackgroundUndifferentiated acute febrile illness (AFI) is a common presentation among adults in primary care settings in Singapore but large gaps exist in the understanding of the characteristics of these patients. We studied clinical and epidemiological characteristics of AFI patients and factors associated with delayed recovery from AFI.MethodsWe performed a secondary data analysis using data from the Early DENgue infection and outcome (EDEN) study on 2046 adult patients presenting at 5 Singapore polyclinics between December 2007 and February 2013 with a history of fever (≥38 °C) for less than 72 h. We used an accelerated failure time model to investigate factors associated with delayed recovery from AFI.ResultsThe mean age of patients was 36.6 years, 65 % were male, 51 % were of Chinese ethnicity, and 75 % lived in public housing. Median illness duration was 5 days (interquartile range, 3–7). In multivariable analysis, the unemployed and white collar workers had longer illness duration compared with blue collar workers (time ratio (TR), 1.10; 95 % confidence interval (CI), 1.03–1.17 and TR, 1.08; 95 % CI, 1.02–1.15, respectively). Patients with more symptoms at initial consultation had slower recovery (TR, 1.03 per additional symptom; 95 % CI, 1.02–1.03). Other clinical factors were also associated with longer duration of illness, including use of analgesics (TR, 1.21; 95 % CI, 1.15–1.28); use of cough medicines (TR, 1.14; 95 % CI, 1.08–1.20); use of antibiotics (TR, 1.14; 95 % CI, 1.07–1.21); and hospitalization (TR, 1.59; 95 % CI, 1.39–1.82). Compared to patients with normal WBC count at first consultation, those with low WBC count had slower recovery (TR, 1.14; 95 % CI, 1.07–1.21), while the reverse was observed among patients with high WBC count (TR, 0.94; 95 % CI, 0.88–1.00).ConclusionsDifferences in illness duration among different types of employment may reflect differences in their underlying general health status. Early identification of factors delaying recovery could help triage management in a primary care setting. In-depth characterization of fever etiology in Singapore will improve surveillance and control activities.

Influence of demographics on clinical outcome of dengue: a cross-sectional study of 6703 confirmed cases in Vitória, Espírito Santo State, Brazil.

Dengue presents a wide clinical spectrum of signs and symptoms, with characteristics of the host potentially influencing the disease evolution. Therefore, the purpose of this study was to evaluate the influence of gender and age on dengue clinical outcomes in a recent outbreak situation in Brazil, applying a cross-sectional design and including 6703 dengue cases with laboratory confirmation, occurring in Vitória, Espírito Santo State, Brazil, between 2007 and 2013. Data were obtained from the Information System for Notifiable Diseases. Overall, 11·3% of the sample presented with severe dengue, which affected 13·0% of males, 10·0% of females, 8·8% of children, 12·5% of adolescents, 10·5% of adults and 15·5% of the elderly. Age was higher in the severe dengue group (P = 0·03). Severe dengue was associated with males and the elderly (P < 0·01); however, considering only severe cases, children presented haemorrhage and plasma leakage more frequently than older age groups. The results emphasize the importance of a differentiated protocol for management of dengue cases, taking into consideration host factors like age. These findings also suggest the elderly and children as priority groups for immunization in a future implementation of a vaccine.

HLA-DRB1 Alleles Are Associated With Different Magnitudes of Dengue Virus-Specific CD4+ T-Cell Responses.

Each year dengue virus (DENV) infects 400 million human but causes symptomatic disease in only a subset of patients, suggesting that host genetic factors may play a role. HLA molecules that restrict T-cell responses are one of the most polymorphic host factors in humans. Here we map HLA DRB1-restricted DENV-specific epitopes in individuals previously exposed to DENV, to identify the breadth and specificity of CD4(+) T-cell responses. To investigate whether HLA-specific variations in the magnitude of response might predict associations between dengue outcomes and HLA-DRB1 alleles, we assembled samples from hospitalized patients with known severity of disease. The capsid protein followed by nonstructural protein 3 (NS3), NS2A, and NS5 were the most targeted proteins. We further noticed a wide variation in magnitude of T-cell responses as a function of the restricting DRB1 allele and found several HLA alleles that showed trends toward a lower risk of hospitalized disease were associated with a higher magnitude of T-cell responses. Comprehensive identification of unique CD4(+) T-cell epitopes across the 4 DENV serotypes allows the testing of T-cell responses by use of a simple, approachable technique and points to important implications for vaccine design.

Behavioural Response to a Sudden Health Risk: Dengue and Educational Outcomes in Colombia

English Abstract: This paper makes use of a short, sharp, unexpected health shock to examine the indirect behavioural response of the general public to a sudden shift in the perceived risk of a substantial deterioration of health and mortality. While existing work has been done estimating the direct effects of an epidemic on the afflicted families, we instead focus on assessing the indirect effect of a sudden epidemic on the population as a whole, mediated by the behavioural response to the sudden shift in the perceived risks of engaging in certain activities. Our analysis finds that the influence of the epidemic extends far beyond those directly afflicted: it essentially comprises a behavioural response to the fear of contracting the disease. Strikingly, we find that close to 4 fewer students, out of a typical class of 47 pupils, sit their school leaving examination for every additional 10 cases of severe Dengue per 10.000 inhabitants in a municipality, but the response to classic Dengue is inconclusive. Spanish Abstract: Este documento utiliza un evento de salud corto e inesperado para analizar la existencia de respuestas indirectas de la poblacion frente a cambios repentinos en el riesgo percibido de un deterioro de salud. El trabajo se enfoca en evaluar los efectos indirectos de un brote epidemico repentino sobre la poblacion como un todo, reconociendo la existencia de otros trabajos que evaluan los efectos directos. El analisis encuentra que la influencia de la epidemia va mas alla de los directamente afectados, mostrando que existe un comportamiento particular en respuesta al temor de contraer la enfermedad. En particular, se encuentra que en un curso con un tamano aproximado de 47 estudiantes, faltan aproximadamente 4 estudiantes a la prueba Saber 11 por cada 10 casos adicionales de dengue hemorragico por 10.000 habitantes, pero la respuesta a casos de dengue clasico no es concluyente.

Lower Low-Density Lipoprotein Cholesterol Levels Are Associated with Severe Dengue Outcome.

Dengue virus (DENV) is a flavivirus of worldwide importance, with approximately 4 billion people across 128 countries at risk of infection, and up to 390 million infections and 96 million clinically apparent cases estimated annually. Previous in vitro studies have shown that lipids and lipoproteins play a role in modifying virus infectivity. However, the relationship between development of severe dengue and total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), respectively, is unclear. We analyzed data from 789 laboratory-confirmed dengue cases and 447 other febrile illnesses (OFI) in a prospective pediatric hospital-based study in Managua, Nicaragua between August 2005 and January 2013, using three different classifications of dengue severity: World Health Organization (WHO) 1997, WHO 2009, and standardized intervention categories. Total serum cholesterol and LDL-C levels decreased over the course of illness and were generally lower with increasing dengue severity, regardless of classification scheme. Greater decreases in LDL-C than HDL-C were observed among dengue-positive patients compared to patients with OFI and among severe dengue compared to mild dengue cases. Furthermore, daily cholesterol levels declined with daily albumin blood levels. To examine the effect of cholesterol at presentation on subsequent risk of development of severe dengue, relative risks and 95% confidence intervals were calculated using multivariable modified Poisson models. We found that lower total serum cholesterol and LDL-C levels at presentation were associated with subsequent risk of developing dengue hemorrhagic fever/dengue shock syndrome using the WHO 1997 dengue severity classification, and thus that the reduction in LDL-C is likely driving the decreases observed in total serum cholesterol levels among dengue-positive patients. Our results suggest that cholesterol blood levels are important correlates of dengue pathophysiology and should be explored as part of a prognostic biomarker panel for severe dengue.

Temperature and the field stability of a dengue rapid diagnostic test in the tropics.

The global incidence of dengue has increased significantly in recent decades, resulting in a large public health burden in tropical and subtropical countries. Dengue rapid diagnostic tests (RDTs) can provide accurate, rapid accessible diagnosis for patient management and may be easily used by health workers in rural areas. However, in dengue-endemic areas, ambient temperatures are often higher than manufacturer's recommendation. We therefore evaluated the effect of high temperature over time on the performance of one commonly used dengue RDT, the Standard Diagnostics Bioline Dengue Duo. RDTs were kept in five different conditions (at 4°C, 35°C, 45°C, 60°C, and at fluctuant ambient temperatures in a free-standing hut) for between 2 days and 2 years in the Lao People's Democratic Republic (PDR). RDTs were tested with four control sera (negative, dengue nonstructural protein 1 [NS1], anti-dengue immunoglobulin [Ig] M, and anti-dengue IgG positive). The RDTs had 100% consistency over the 2-year study, despite high temperatures, including in the hut in which temperatures exceeded the manufacturer's recommendations for 29% of time points. These data suggest that the diagnostic accuracy of the SD Bioline Dengue Duo RDT remains stable even after long-term storage at high temperatures. Therefore, use at such ambient temperatures in tropical areas should not jeopardize the dengue diagnostic outcome.

Differential clinical outcome of dengue infection among patients with and without HIV infection: a matched case-control study.

Clinical characteristics and outcome among dengue patients with and without human immunodeficiency virus (HIV) infection remain elusive. A total of 10 dengue virus (DENV)–HIV Chinese patients were compared with 40 Chinese dengue patients without HIV, who were matched for age, gender, type of care received, methods, and year of dengue diagnosis from 2005 to 2008. Univariate and multivariate conditional logistics regression were applied. DENV-HIV patients were significantly associated with the World Health Organization (WHO) 2009 severe dengue (conditional odds ratio [COR] = 5.72; 95% confidence interval [CI] = 1.01–32.64) but not with the WHO 1997 dengue hemorrhagic fever/dengue shock syndrome (COR = 0.40; 95% CI = 0.09–1.71). This is mainly due to severe plasma leakage and the lack of hemorrhagic manifestations. Hospitalization duration was longer for DENV-HIV patients (10.5 days; interquartile range [IQR] = 5.5–26.3 days) compared with dengue patients (5 days; IQR = 4–6 days). There were no significant differences in presentation of clinical warning signs and symptoms at admission and during hospitalization, except for rash (adjusted COR [ACOR] = 0.06; 95% CI = 0.03–0.92). DENV-HIV patients were associated with higher pulse rate (ACOR = 1.13; 95% CI = 1.02–1.25), eosinophils proportion (ACOR = 3.07; 95% CI = 1.12–8.41) and lower hematocrit level (ACOR = 0.79; 95% CI = 0.64–0.98) compared with dengue patients. Even though DENV-HIV patients may present similarly to dengue patients, they may be more likely to have severe dengue outcome. Hence, close monitoring of DENV-HIV patients is highly recommended as part of dengue clinical care and management.

Is dengue a disease of poverty? A systematic review

Policy prescriptions for combating dengue fever tend to focus on addressing environmental and social conditions of poverty. However, while poverty has long been considered a determinant of dengue, the research evidence for such a relationship is not well established. Results of a systematic review of the research literature designed to identify and assess the current state of the empirical evidence for the dengue–poverty link reveal a mixed story. Of 260 peer-reviewed articles referencing dengue–poverty relationships, only 12 English-language studies empirically assessed these relationships. Our analysis covering various social and economic conditions of poverty showed no clear associations with dengue rates. While nine of the 12 studies demonstrated some positive associations between measures of dengue and poverty (measured inconsistently through income, education, structural housing condition, overcrowding, and socioeconomic status), nine also presented null results and five with negative results. Of the five studies relating to access to water and sanitation, four reported null associations. Income and physical housing conditions were more consistently correlated with dengue outcomes than other poverty indicators. The small size of this sample, and the heterogeneity of measures and scales used to capture conditions of poverty, make it difficult to assess the strength and consistency of associations between various poverty indicators and dengue outcomes. At present, the global body of eligible English-language peer-reviewed literature investigating dengue–poverty relationships is too small to support a definitive relationship. We conclude that more research, particularly using standardized measures of both outcomes and indicators, is needed to support evidence-informed policies and approaches.

Ferritin levels predict severe dengue.

Currently, no tests are available to monitor and predict severity and outcome of dengue. To find potential markers that predict dengue severity, the present study validated the serum level of three acute-phase proteins α-1 antitrypsin, ceruloplasmin and ferritin in a pool of severe dengue cases compared to non-severe forms and other febrile illness controls. A total of 96 patients were divided into two equal groups with group 'A' comprising dengue-infected cases and group 'B' with other febrile illness cases negative for dengue. Out of 48 dengue-infected cases, 13 had severe dengue and the remaining 35 were classified as non-severe dengue. Immunoassays were performed to evaluate the serum levels of acute-phase proteins both on the day of admission and on the day of defervescence. The efficiency of individual proteins in predicting the disease severity was assessed using receiver operating characteristic curve. The study did not find any significant difference in the levels of α-1 antitrypsin between the clinical groups. A significant increase in the levels of ceruloplasmin around defervescence in severe cases compared to non-severe and other febrile controls was observed and this is the first report describing the potential association of ceruloplasmin and dengue severity. Interestingly, a steady increase in the level of serum ferritin was recorded throughout the course of illness. Among all the three proteins, the elevated ferritin level could predict the disease severity with highest sensitivity and specificity of 76.9 and 83.3 %, respectively, on the day of admission and the same was found to be 90 and 91.6 % around defervescence. On the basis of this diagnostic efficiency, we propose that ferritin may serve as a potential biomarker for an early prediction of disease severity.

Challenges in Dengue Fever in the Elderly: Atypical Presentation and Risk of Severe Dengue and Hospita-Acquired Infection

Background/methodsTo better understand dengue fever in the elderly, we compared clinical features, World Health Organization (WHO) dengue classification and outcomes between adult (<60) and elderly (≥60) dengue patients. We explored the impact of co-morbidity and hospital-acquired infection (HAI) on clinical outcomes in the elderly. All patients managed at the Communicable Disease Centre, Singapore, between 2005 and 2008 with positive dengue polymerase chain reaction (PCR) or who fulfilled WHO 1997 or 2009 probable dengue criteria with positive dengue IgM were included.ResultsOf the 6989 cases, 295 (4.4%) were elderly. PCR was positive in 29%. The elderly suffered more severe disease with more dengue haemorrhagic fever (DHF) (29.2% vs. 21.4%) and severe dengue (SD) (20.3% vs. 14.6%) (p<0.05). Classic dengue symptoms were more common in the adult group. The elderly were less likely to fulfill WHO 1997 (93.6% vs. 96.4%) (p = 0.014), but not WHO 2009 probable dengue (75.3% vs. 71.5%). Time to dengue diagnosis was similar. There was no significant difference in the frequency of warning signs between the two groups, but the elderly were more likely to have hepatomegaly (p = 0.006) and malaise/lethargy (p = 0.033) while the adults had significantly more mucosal bleeding (p<0.001). Intensive care admission occurred in 15 and death in three, with no age difference. Notably, the elderly stayed in hospital longer (median 5 vs. 4 days), and suffered more pneumonia (3.8% vs. 0.7%) and urinary infection (1.9% vs. 0.3%) (p = 0.003). Predictors of excess length of stay were age (adjusted odds ratio [aOR] 2.01, 95% confidence interval [CI] 1.37–2.88), critical illness (aOR 5.13, 95%CI 2.59–9.75), HAI (aOR 12.06, 95%CI 7.39–19.9), Charlson score (aOR 6.9, 95%CI 2.02–22.56) and severe dengue (DHF/dengue shock syndrome/SD) (aOR 2.24, 95%CI 1.83–2.74).ConclusionElderly dengue patients present atypically and are at higher risk of DHF, SD and HAI. Aside from dengue severity, age, co-morbidity and HAI were associated with longer hospital stay.