Accuracy and applicability of the revised WHO classification (2009) of dengue in children seen at a tertiary healthcare facility in northern India

Severe dengue in the intensive care unit

Dengue fever is considered the most prolific vector-borne disease in the world, with its transmission rate increasing more than eight times in the last two decades. While most cases present mild to moderate symptoms, 5% of patients can develop severe disease. Although the mechanisms are yet not fully comprehended, immune-mediated activation leading to excessive cytokine expression is suggested as a cause of the two main findings in critical patients: increased vascular permeability that may shock and thrombocytopenia, and coagulopathy that can induce hemorrhage. The risk factors of severe disease include previous infection by a different serotype, specific genotypes associated with more efficient replication, certain genetic polymorphisms, and comorbidities such as diabetes, obesity, and cardiovascular disease. The World Health Organization recommends careful monitoring and prompt hospitalization of patients with warning signs or propensity for severe disease to reduce mortality. This review aims to update the diagnosis and management of patients with severe dengue in the intensive care unit.

Frequency of pleural effusion in dengue patients by severity, age and imaging modality: a systematic review and meta-analysis

BACKGROUND

Identification of pleural effusion (PE) in dengue infection is an objective measure of plasma leakage and may predict disease progression. However, no studies have systematically assessed the frequency of PE in patients with dengue, and whether this differs across age and imaging modality.

METHODS

We searched Pubmed, Embase Web of Science and Lilacs (period 1900-2021) for studies reporting on PE in dengue patients (hospitalized and outpatient). We defined PE as fluid in the thoracic cavity detected by any imaging test. The study was registered in PROSPERO (CRD42021228862). Complicated dengue was defined as hemorrhagic fever, dengue shock syndrome or severe dengue.

RESULTS

The search identified 2,157 studies of which 85 studies were eligible for inclusion. The studies (n = 31 children, n = 10 adults, n = 44 mixed age) involved 12,800 patients (30% complicated dengue). The overall frequency of PE was 33% [95%CI: 29 to 37%] and the rate of PE increased significantly with disease severity (P = 0.001) such that in complicated vs. uncomplicated dengue the frequencies were 48% and 17% (P < 0.001). When assessing all studies, PE occurred significantly more often in children compared to adults (43% vs. 13%, P = 0.002) and lung ultrasound more frequently detected PE than conventional chest X-ray (P = 0.023).

CONCLUSIONS

We found that 1/3 of dengue patients presented with PE and the frequency increased with severity and younger age. Importantly, lung ultrasound demonstrated the highest rate of detection. Our findings suggest that PE is a relatively common finding in dengue and that bedside imaging tools, such as lung ultrasound, potentially may enhance detection.

Successful Outpatient Management of Children at a Secondary Care Hospital in Pakistan in a Dengue Fever Epidemic and Their Clinical Outcomes

Background

There is limited published literature on the feasibility of WHO 2009 guidelines for the management of dengue fever (DF) in Pakistani children. This study aimed to assess the outcome of children with DF who received outpatient treatment according to these guidelines during a DF epidemic.

Method

This was a prospective cohort study conducted at Federal General Hospital, a secondary care hospital, Islamabad, Pakistan, from 1st August to 31st October 2019. Using WHO DF 2009 guidelines, children ≤13 years, diagnosed as confirmed DF (NS1 Ag +), were classified into the outpatient (DF) or the inpatient group (DF with warning signs or severe dengue (SD)). The inpatient group was admitted to the Pakistan Institute of Medical Sciences, a tertiary care hospital, and discharged on recovery. These children were followed for the primary outcome, i.e., recovery or hospitalization by day 14 of enrollment. Additionally, clinical and laboratory features (Hb, HCT, TLC, PLT, and ALT) of the patients in the outpatient who remained stable with those who progressed to inpatient care during follow-up were compared; also, time of recovery of blood counts was assessed.

Results

Of 93 children with DF, 87 (93.5%) received outpatient care at enrollment. Of these, 6 (7.8%) deteriorated by day 7 and were admitted to inpatient care. SD was present in 6/93 (6.4%) patients at presentation and were admitted. All children showed signs of recovery until day 14. Male gender (p=0.049), lower normal mean platelet (p=0.02), and high mean hematocrit (p=0.001) were associated with disease progression.

Conclusion

The majority of children with confirmed DF who received outpatient treatment according to WHO 2009 guidelines were successfully managed. Additionally, confirmed DF with warning signs or SD were admitted and recovered. Regular follow-ups according to the guidelines are pertinent. Thrombocytopenia and high HCT were associated with disease progression.

Clinical signs and symptoms associated with WHO severe dengue classification: a systematic review and meta-analysis

The World Health Organization (WHO) introduced the new dengue classification in 2009. We aimed to assess the association of clinical signs and symptoms with WHO severe dengue classification in clinical practice. A systematic literature search was performed using the databases of PubMed, Embase, and Scopus between 2009 and 2018 according to PRISMA guideline. Meta-analysis was performed with the RevMan software. A random or fixed-effect model was applied to pool odds ratios and 95% confidence intervals of important signs and symptoms across studies. Thirty nine articles from 1790 records were included in this review. In our meta-analysis, signs and symptoms associated with higher risk of severe dengue were comorbidity, vomiting, persistent vomiting, abdominal pain or tenderness, pleural effusion, ascites, epistaxis, gum bleeding, GI bleeding, skin bleeding, lethargy or restlessness, hepatomegaly (>2 cm), increased HCT with decreased platelets, shock, dyspnea, impaired consciousness, thrombocytopenia, elevated AST and ALT, gall bladder wall thickening and secondary infection. This review shows new factors comorbidity, epistaxis, GI and skin bleeding, dyspnea, gall bladder wall thickening and secondary infection may be useful to refine the 2009 classification to triage severe dengue patients.

Clinical Profile, Liver Dysfunction and Outcome of Dengue Infection in Children: A Prospective Observational Study

BACKGROUND

Liver involvement in dengue illness is common and can lead to acute liver failure (ALF). No single method can effectively identify patients at risk for disease progression and bad outcome. We aimed to determine the relationship between liver dysfunction, kinetics of liver function tests (LFTs) and severity of hepatitis on the outcome in pediatric dengue illness.

METHODS

We conducted a prospective observational study of hospitalized children (1-12 years) with dengue infection (July 2014-July 2015). Serial monitoring of LFTs was done in confirmed dengue cases. Patients were classified into non-severe (NSD) and severe dengue (SD). Severity of hepatitis was graded: mild, moderate and severe hepatitis. Events were noted during hospitalization.

RESULTS

One hundred two children (66, boys), median age 72 (48-96) months, were analyzed (NSD, n = 41; SD, n = 61). Elevated transaminases (92%) was the most common abnormality; aspartate transaminase (AST) and alanine transaminase (ALT) in 87% and 82%, respectively. Maximum abnormalities in LFTs peaked at day 5 (AST, ALT) and day 7 (Alkaline Phosphatase [ALP], gamma-glutamyl transferase) of illness. Elevated transaminases was found to be higher in SD than NSD (100% vs. 80%, P = 0.006). Severe hepatitis developed organ dysfunction such as altered sensorium (P < 0.001), ALF (P < 0.001), acute kidney injury (P < 0.001) and shock (P < 0.001), more commonly than those with mild to moderate hepatitis. Fourteen patients died, two-thirds of whom had severe hepatitis (P < 0.001). Using binary logistic regression, presence of severe hepatitis and shock at presentation was an independent predictor for ALF (odds ratio: 77; 95% confidence interval : 13-457, P < 0.001) and mortality (odds ratio: 55; 95% confidence interval: 4.6-66, P < 0.001), respectively.

CONCLUSIONS

Many children with dengue have liver involvement. Severe hepatitis in dengue is associated with significant organ dysfunction and poor outcome.

Knowledge, attitude and practice towards dengue fever prevention and associated factors among public health sector health-care professionals: in Dire Dawa, eastern Ethiopia

Background: The Ethiopian national strategy for the prevention, control and elimination of malaria is one of the Health Development Programs (HDP IV). Dengue fever is one of the vector borne diseases that causes Acute Febrile Illness and death in tropical and sub-tropical countries. Knowledge, attitude and practice of health-care professionals towards dengue fever prevention and associated factors among health professionals is not yet well known across the country and concern is varied in context and place. Therefore, the aim of this research was to assess knowledge, attitude and practice towards dengue fever prevention and associated factors among public health sector health-care professionals in Dire Dawa administrative city, eastern Ethiopia.

Materials and methods: An Institution-based cross sectional study was conducted from September 9 to October 13, 2017. The study was conducted among a sample of 348 health-care professionals which were from the randomly selected nine clusters of public health facilities located in urban and rural areas of Dire Dawa. Data were collected by self-administered structured questionnaire. Bivariate and multinomial logistic regression analyses were made to check the associations among predictor variables and to control for confounding factors. A P-value <0.05 was used to declare statistical significance.

Results: Of the 348 sampled health-care professionals, 300 were included in the analysis giving a response rate of 86.2%. Nearly half (148/49.3%) of the participants demonstrated a moderate level of knowledge, 140 (46.7%) a neutral level of attitude and 156 (52%) a low level of practice towards dengue fever prevention. Multinomial logistic regression revealed that type of health profession, type of health facility and dengue fever prevention training status were significantly associated with the knowledge, attitude and practice of health-care professionals. The odds of physicians and public-health officers having a high level of knowledge or a low knowledge level were (AOR [95% CI] =38.793 [7.279, 206.734]) and (AOR[95% CI] =6.15[1.643, 23.026]) times higher than the odds for nurse professionals. The odds for professionals who worked in health centers and had a high knowledge level towards dengue fever prevention were (AOR [95% CI] =0.252 [0.086, 0.737]) times higher than those working in referral hospitals. The odds of health-care professionals who were public-health officers and those who worked in primary hospitals having a favorable attitude towards dengue fever prevention were (AOR [95% CI] =7.011 [1.867, 26.321]) and (AOR [95% CI] =3.683 [1.284, 10.563]) times higher than the odds for nurse professionals and those who worked in a referral hospital setting respectively. The odds of health-care professionals who took dengue fever prevention training were 10.23 times (AOR [95% CI] =10.23 [1.052, 99.478]) higher than the odds for health-care professionals who had not received the training.

Conclusion: Knowledge attitude and practice of health-care professionals were not satisfactory towards dengue fever. Additional training is required to plug this gap. Thus, the regional health bureau and stakeholders should follow up and provide support including provision of the World Health Organization’s standardized guidelines of dengue fever prevention. We recommend similar studies to be done specifically in Ethiopia and elsewhere to better understand the gaps.

Classification of dengue cases in Southwest India based on the WHO systems-a retrospective analysis

Background

The WHO dengue classification 1997 was revised in 2009 and the revised classification system has now been in use for the past decade. This study was carried out to compare the 1997 and revised classifications in assessing the severity of dengue infection among all age groups during a dengue outbreak in southwest India.

Methodology

This retrospective cross-sectional study was carried out including serologically confirmed dengue cases. A total of 1033 dengue cases were classified on the basis of the 1997 WHO classification and 2009 revised classification. The statistical analysis was carried out using SPSS 15.0 for Windows (SPSSTM Inc, Chicago, IL, USA).

Results

Both the 1997 and revised WHO classifications were applied to 1033 confirmed dengue cases, including 692 males (67%) and 341 females (33%). The median age of the study participants was 23 years (IQR 10-33), including 112 (10.8%) children at and below the age of 5 years. The level of agreement between the two systems of classification was poor (kappa=0.143, 0.055-0.198, p-value <0.001).

Conclusion

A greater sensitivity and specificity of the revised classification was observed in comparison with the 1997 WHO classification. In the context of changing dengue epidemiology and geographical expansion, the revised classification is helpful in the identification of severe cases, facilitating timely management.

Dengue infection in India: A systematic review and meta-analysis

INTRODUCTION

Dengue is the most extensively spread mosquito-borne disease; endemic in more than 100 countries. Information about dengue disease burden, its prevalence, incidence and geographic distribution is critical in planning appropriate control measures against dengue fever. We conducted a systematic review and meta-analysis of dengue fever in India.

METHODS

We searched for studies published until 2017 reporting the incidence, the prevalence or case fatality of dengue in India. Our primary outcomes were (a) prevalence of laboratory confirmed dengue infection among clinically suspected patients, (b) seroprevalence in the general population and (c) case fatality ratio among laboratory confirmed dengue patients. We used binomial-normal mixed effects regression model to estimate the pooled proportion of dengue infections. Forest plots were used to display pooled estimates. The metafor package of R software was used to conduct meta-analysis.

RESULTS

Of the 2285 identified articles on dengue, we included 233 in the analysis wherein 180 reported prevalence of laboratory confirmed dengue infection, seven reported seroprevalence as evidenced by IgG or neutralizing antibodies against dengue and 77 reported case fatality. The overall estimate of the prevalence of laboratory confirmed dengue infection among clinically suspected patients was 38.3% (95% CI: 34.8%-41.8%). The pooled estimate of dengue seroprevalence in the general population and CFR among laboratory confirmed patients was 56.9% (95% CI: 37.5-74.4) and 2.6% (95% CI: 2-3.4) respectively. There was significant heterogeneity in reported outcomes (p-values<0.001).

CONCLUSIONS

Identified gaps in the understanding of dengue epidemiology in India emphasize the need to initiate community-based cohort studies representing different geographic regions to generate reliable estimates of age-specific incidence of dengue and studies to generate dengue seroprevalence data in the country.

Dengue-specific serotype related to clinical severity during the 2012/2013 epidemic in centre of Brazil

Multilingual abstracts

Please see Additional file 1 for translations of the abstract into the five official working languages of the United Nations.

Background

Currently, in Brazil, there is a co-circulation of the four dengue (DENV-1 to DENV-4) serotypes. This study aimed to assess whether different serotypes and antibody response patterns were associated with the severity of the disease during a dengue outbreak, which occurred in 2012/2013 in centre of Brazil.

Methods

We conducted a prospective study with 452 patients with laboratory confirmed dengue in central Brazil, from January 2012 to July 2013. The clinical outcome was the severity of cases: dengue, dengue with warning signs, and severe dengue. The patients were evaluated at three different moments. Blood sampling for laboratory testing and confirmatory tests for dengue infection were performed. We performed a multinomial analysis considering the three categories of the dependent variable, as outlined above. The odds ratios (ORs) were calculated. A multinomial logistic regression model was applied for variables with a P-value <0.20. Statistical analysis was performed with STATA 12.0 software.

Results

Four hundred fifty-two patients (452/632, 71.5%) were diagnosed with dengue. The dengue virus (DENV) serotypes were identified in 243 cases. DENV-4 was detected in 135 patients (55.6%), DENV-1 in 91 (37.4%), DENV-3 in 13 (5.3%), and DENV-2 in 4 (1.6%). Patients with the DENV-1 serotype were more prone to present with several clinical and laboratory features as compared with DENV-4 patients, including spontaneous bleeding (P = 0.03), intense abdominal pain (P = 0.004), neurological symptoms (P = 0.09), and thrombocytopenia (P = 0.01). Secondary infection was more predominant among DENV-4 cases (80.0%) compared with DENV-1 cases (62.3%) (P = 0.03). The univariate analysis showed that females (OR = 2.12; 95% CI: 1.44–3.13; P < 0.01) had a higher risk of having dengue with warning signs. The multinomial analysis showed that severe dengue cases with secondary infection had an adjusted OR of 2.80 (95% CI: 0.78–10.00; P = 0.113) as compared with dengue fever with primary infection when adjusted for age and sex.

Conclusion

The current data show that 5.8% of patients recruited for treatment in healthcare centres and hospitals during the study period had severe dengue. DENV-4 was the predominant serotype, followed by DENV-1, in a large outbreak of dengue in central Brazil. Our findings contribute to the understanding of clinical differences and immune status related to the serotypes DENV-1 and DENV-4 in central of Brazil.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0328-9) contains supplementary material, which is available to authorized users.

Dengue

Dengue is one of the most important mosquito-borne viral infections caused by single-stranded RNA virus that are transmitted by the Aedes aegypti and Aedes albopictus mosquito species. Dengue is endemic in over 140 countries in Asia, the USA, the Eastern Mediterranean, and Africa. The World Health Organization (WHO) estimated that there are more than 2.5 billion people—mainly occurs in children living in tropical and subtropical countries—at risk of dengue infection with one or more dengue viruses. There are estimated nearly 100 million symptomatic dengue infections occurring worldwide annually, nearly 75% in Asia and the Western Pacific region [1]. During the past decades, the outbreaks of dengue infection have been reported throughout the world with increased severity. Ecologic and demographic changes are considered to be the contributing factors to the emergence of dengue infection in the past decades. Dengue has expanded into new countries and into urban settings associated with increased distribution of A. aegypti, population growth, urbanization, development of slums, migration of population, movement of dengue virus by infected travelers, trade development, and improved diagnostic capabilities in medical practice [2, 3]. Increased transmission of dengue virus in tropical urban areas has been created by substandard housing and crowding as well as deterioration in water, sewer, and waste management systems, all of which are intimately associated with unplanned urbanization [4–7]. So it is likely that dengue will expand its geographic reach and become an increasing burden on health resources in affected areas during the next decade. An effective vector-control management is the only means to reduce dengue infection in endemic areas. Because vector control has achieved only limited success so far in reducing the transmission of dengue, the usage of effective dengue vaccine in target population along with the preventive measures already used such as raising public awareness may be the means to effectively control of this disease in endemic area [8].

Dengue infection

Dengue is widespread throughout the tropics and local spatial variation in dengue virus transmission is strongly influenced by rainfall, temperature, urbanization and distribution of the principal mosquito vector Aedes aegypti. Currently, endemic dengue virus transmission is reported in the Eastern Mediterranean, American, South-East Asian, Western Pacific and African regions, whereas sporadic local transmission has been reported in Europe and the United States as the result of virus introduction to areas where Ae. aegypti and Aedes albopictus, a secondary vector, occur. The global burden of the disease is not well known, but its epidemiological patterns are alarming for both human health and the global economy. Dengue has been identified as a disease of the future owing to trends toward increased urbanization, scarce water supplies and, possibly, environmental change. According to the WHO, dengue control is technically feasible with coordinated international technical and financial support for national programmes. This Primer provides a general overview on dengue, covering epidemiology, control, disease mechanisms, diagnosis, treatment and research priorities.

Knowledge, attitudes, and practices regarding dengue infection among public sector healthcare providers in Machala, Ecuador

Background

Dengue fever is a rapidly emerging infection throughout the tropics and subtropics with extensive public health burden. Adequate training of healthcare providers is crucial to reducing infection incidence through patient education and collaboration with public health authorities. We examined how public sector healthcare providers in a dengue-endemic region of Ecuador view and manage dengue infections, with a focus on the 2009 World Health Organization (WHO) Dengue Guidelines.

Methods

A 37-item questionnaire of dengue knowledge, attitudes, and practices was developed and administered to dengue healthcare providers in Machala, Ecuador. Survey focus areas included: “Demographics,” “Infection and Prevention of Dengue,” “Dengue Diagnosis and the WHO Dengue Guide,” “Laboratory Testing,” “Treatment of Dengue,” and “Opinions Regarding Dengue.”

Results

A total of 76 healthcare providers participated in this study, of which 82 % were medical doctors and 14 % were nurses. Fifty-eight percent of healthcare professionals practiced in ambulatory clinics and 34 % worked in a hospital. Eighty-nine percent of respondents were familiar with the 2009 WHO Dengue Guidelines, and, within that group, 97 % reported that the WHO Dengue Guide was helpful in dengue diagnosis and clinical management. Knowledge gaps identified included Aedes aegypti mosquito feeding habits and dengue epidemiology. Individuals with greater dengue-related knowledge were more likely to consider dengue a major health problem. Only 22 % of respondents correctly reported that patients with comorbidities and dengue without warning signs require hospital admission, and 25 % of providers reported never admitting patients with dengue to the hospital. Twenty percent of providers reported rarely (≤25 % of cases) obtaining laboratory confirmation of dengue infection. Providers reported patient presumptive self-medication as an ongoing problem. Thirty-one percent of healthcare providers reported inadequate access to resources needed to diagnose and treat dengue.

Conclusion

Participants demonstrated a high level of knowledge of dengue symptoms and treatment, but additional training regarding prevention, diagnosis, and admission criteria is needed. Interventions should not only focus on increasing knowledge, but also encourage review of the WHO Dengue Guidelines, avoidance of presumptive self-medication, and recognition of dengue as a major health problem. This study provided an assessment tool that effectively captured healthcare providers’ knowledge and identified critical gaps in practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s40794-016-0024-y) contains supplementary material, which is available to authorized users.

Evaluation of the World Health Organization 2009 classification of dengue severity in autopsied individuals, during the epidemics of 2011 and 2012 in Brazil

INTRODUCTION

The dengue classification proposed by the World Health Organization (WHO) in 2009 is considered more sensitive than the classification proposed by the WHO in 1997. However, no study has assessed the ability of the WHO 2009 classification to identify dengue deaths among autopsied individuals suspected of having dengue. In the present study, we evaluated the ability of the WHO 2009 classification to identify dengue deaths among autopsied individuals suspected of having dengue in Northeast Brazil, where the disease is endemic.

METHODS

This retrospective study included 121 autopsied individuals suspected of having dengue in Northeast Brazil during the epidemics of 2011 and 2012. All the autopsied individuals included in this study were confirmed to have dengue based on the findings of laboratory examinations.

RESULTS

The median age of the autopsied individuals was 34 years (range, 1 month to 93 years), and 54.5% of the individuals were males. According to the WHO 1997 classification, 9.1% (11/121) of the cases were classified as dengue hemorrhagic fever (DHF) and 3.3% (4/121) as dengue shock syndrome. The remaining 87.6% (106/121) of the cases were classified as dengue with complications. According to the 2009 classification, 100% (121/121) of the cases were classified as severe dengue. The absence of plasma leakage (58.5%) and platelet counts <100,000/mm3 (47.2%) were the most frequent reasons for the inability to classify cases as DHF.

CONCLUSIONS

The WHO 2009 classification is more sensitive than the WHO 1997 classification for identifying dengue deaths among autopsied individuals suspected of having dengue.

Clinical profile of dengue among children according to revised WHO classification: analysis of a 2012 outbreak from Southern India

OBJECTIVE

To study the clinical profile of dengue fever and its outcome in children with application of revised WHO classification and to identify risk factors for severe dengue.

METHODS

This study was a prospective observational study of children diagnosed with dengue from July 2012 through February 2013 at a tertiary care hospital in Bangalore, Karnataka (South India).

RESULTS

Eighty one children including 55(67.9 %) boys and 26(32.1 %) girls were diagnosed with dengue. Mean age of presentation was 8 y. Vomiting (60.5 %), pain abdomen (32 %), headache (30.9 %), myalgia (23.5 %) and bleeding manifestations (16 %) were the common presenting complaints. Facial puffiness (63 %), hepatomegaly (51.9 %), ascites (48.1 %), pleural effusion (39.5 %) and petechiae (14.8 %) were noted during examination. Dengue NS1 antigen, IgM, IgG were positive in 66.7 %, 29.6 % and 18.5 % of cases respectively. Investigations showed hemoconcentration in 72.8 %, leucopenia (34.5 %), thrombocytopenia (82.7 %), abnormal liver function test (LFT) (33.3 %). USG abdomen was suggestive of dengue in 66.7 % and gall bladder edema was noted in 53.1 %. Two patients died out of the total 81 patients with mortality rate of 2.5 %. Number of cases classified as Dengue without warning signs (D), Dengue with warning signs (DW) and Severe Dengue (SD) were 48.1 %, 27.2 % and 24.7 % respectively.

CONCLUSIONS

Children between 5 and 15 y were most affected by dengue fever. Pain abdomen and vomiting were most common presenting symptoms. Ascites, plerural effusion, hepatomegaly, gall bladder wall thickening and abnormal LFT were found significantly high in severe dengue cases.

WHO dengue case classification 2009 and its usefulness in practice: an expert consensus in the Americas

INTRODUCTION

In 2009, the new World Health Organization (WHO) dengue case classification - dengue/severe dengue (D/SD) - was introduced, replacing the 1997 WHO dengue case classification: dengue fever/dengue haemorrhagic fever/dengue shock syndrome (DF/DHF/DSS).

METHODS

A 2-day expert consensus meeting in La Habana/Cuba aimed to (1) share the experiences from Pan American Health Organization (PAHO) member states when applying D/SD, (2) present national and local data using D/SD, and (3) agree with the presented evidence on a list of recommendations for or against the use of D/SD for PAHO, and also globally.

RESULTS

Eight key questions were discussed, concluding: (1) D/SD is useful describing disease progression because it considers the dynamic nature of the disease, (2) D/SD helps defining dengue cases correctly for clinical studies, because it defines more precisely disease severity and allows evaluating dynamically the progression of cases, (3) D/SD describes correctly all clinical forms of severe dengue. Further standards need to be developed regionally, especially related to severe organ involvement, (4) D/SD allows for pathophysiological research identifying - in a sequential manner - the clinical manifestations of dengue related to pathophysiological events, (5) the warning signs help identifying early cases at risk of shock (children and adults), pathophysiology of the warning signs deserves further studies, (6) D/SD helps treating individual dengue cases and also the reorganization of health-care services for outbreak management, (7) D/SD helps diagnosing dengue, in presumptive diagnosis and follow-up of the disease, because of its high sensitivity and high negative predictive value (NPV), and (8) there is currently no update of the International Disease Classification10 (ICD10) to include the new classification of dengue (D/SD); therefore, there are not enough experiences of epidemiological reporting. Once D/SD has been implemented in epidemiological surveillance, D/SD allows to (1) identify severity of dengue cases in real time, for any decision-making on actions, (2) measure and compare morbidity and mortality in countries, and also globally, and (3) trigger contingency plans early, not only based on the number of reported cases but also on the reported severity of cases.

CONCLUSION

The expert panel recommends to (1) update ICD10, (2) include D/SD in country epidemiological reports, and (3) implement studies improving sensitivity/specificity of the dengue case definition.

Characterization of the dengue outbreak in Nuevo Leon state, Mexico, 2010

We studied serotypes circulating dengue virus (DENV) cases, entomological Breteau index, rain-fall index and epidemiology of groups affected during the 2010 outbreak in Nuevo Leon, Mexico. From 2,271 positive cases, 94% were dengue classic and 6% dengue hemorrhagic fever; DENV1 was mainly isolated (99%) (Central-American lineage of American-African-genotype). We found correlation between two environmental phenomena (Increment of rainfall and vector-indexes) (p ≤ 0.05) with epidemiological, clinical and risk of DENV-1 ongoing transmission.

Comparing the usefulness of the 1997 and 2009 WHO dengue case classification: a systematic literature review

The 1997 and 2009 WHO dengue case classifications were compared in a systematic review with 12 eligible studies (4 prospective). Ten expert opinion articles were used for discussion. For the 2009 WHO classification studies show: when determining severe dengue sensitivity ranges between 59-98% (88%/98%: prospective studies), specificity between 41-99% (99%: prospective study) - comparing the 1997 WHO classification: sensitivity 24.8-89.9% (24.8%/74%: prospective studies), specificity: 25%/100% (100%: prospective study). The application of the 2009 WHO classification is easy, however for (non-severe) dengue there may be a risk of monitoring increased case numbers. Warning signs validation studies are needed. For epidemiological/pathogenesis research use of the 2009 WHO classification, opinion papers show that ease of application, increased sensitivity (severe dengue) and international comparability are advantageous; 3 severe dengue criteria (severe plasma leakage, severe bleeding, severe organ manifestation) are useful research endpoints. The 2009 WHO classification has clear advantages for clinical use, use in epidemiology is promising and research use may at least not be a disadvantage.

Utility of warning signs in guiding admission and predicting severe disease in adult dengue

BACKGROUND

The recommendation from the 2009 World Health Organization guidelines for managing dengue suggests that patients with any warning sign can be hospitalized for observation and management. We evaluated the utility of using warning signs to guide hospital admission and predict disease progression in adults.

METHODS

We conducted a prospective cohort study from January 2010 to September 2012. Daily demographic, clinical and laboratory data were collected from adult dengue patients. Warning signs were recorded. The proportion of admitted patients using current admission criteria and warning signs was compared. The sensitivity, specificity, positive and negative predictive values of warning signs in predicting disease progression were also evaluated.

RESULTS

Four hundred and ninety-nine patients with confirmed dengue were analyzed. Using warning signs instead of the current admission criteria will lead to a 44% and 31% increase in admission for DHF II-IV and SD cases respectively. The proportion of non-severe dengue cases which were admitted also increased by 32% for non DHF II-IV and 33% for non-SD cases. Absence of any warning signs had a NPV of 91%, 100% and 100% for DHF I-IV, DHF II-IV and SD. Of those who progressed to severe illness, 16.3% had warning signs on the same day while 51.3% had warning signs the day before developing severe illness, respectively.

CONCLUSIONS

Our findings demonstrated that patients without any warning signs can be managed safely with ambulatory care to reduce hospital resource burden. No single warning sign can independently predict disease progression. The window from onset of warning sign to severe illness in most cases was within one day.