Identifying Adult Dengue Patients at Low Risk for Clinically Significant Bleeding

Development and Validation of a Prediction Score for Critical Admission in Children With Dengue

OBJECTIVES

This study aimed to develop and validate a clinical score for the prediction of critical care entrance in children with dengue.

METHODS

We conducted a retrospective cohort study using admissions from January 2019 to August 2021, at Hospital Infantil Napoleón Franco Pareja, in Cartagena, Colombia. We included all children 18 years or younger, with a positive immunoglobulin M or nonstructural protein 1 laboratory test and admitted for follow-up at the emergency department. We selected variables retrospectively collected on emergency admission for feature selection. We assessed discrimination and calibration in the development dataset, using 1000 bootstrap replications for internal validation. Data from 2019 to 2020 were used for development and 2021 for temporal validation. We report the c -statistic for discrimination with 95% confidence intervals (CIs), as well as the calibration intercept and slope.

RESULTS

One thousand three hundred eighty-five patients were included for development and internal validation. In temporal validation with 519 additional patients, the c -statistic was 0.82 (95% CI: 0.77-0.87), with a calibration slope of 0.98 (95% CI: 0.77-1.18). We selected the 50 th percentile of the distribution of predicted probability of critical care entrance (5%) as a threshold value for increased alert at emergency admission, missing 10% of all cases that need to enter critical care (sensitivity of 90% with 95% CI of 82-95, and specificity of 48% with 95% CI of 41-50).

CONCLUSIONS

Our validated model can be useful to predict critical care entrance in children with dengue. We recommend the validation and potential recalibration of our score in other clinical settings.

Utility of High Fluorescent Cell Parameter on Automated Hematology Analyzer in Screening for Dengue Infection and Predicting Platelet Recovery: Objective and Cost-Effective Solution

Background and objective Dengue is a common febrile illness in tropical countries; serological detection of non-structural protein-1 (NS1) antigen or IgM is the gold standard for diagnosis. Thrombocytopenia, leukopenia, eosinopenia, and hem concentration are common hematological manifestations in dengue, and activated lymphocytes are seen in these patients. We intend to analyze the utility of a parameter called a high fluorescent cell (HFC) on Mindray BC-6000 for suspecting dengue infection in patients with febrile illness. Thrombocytopenia, when present, is taken as a warning sign and creates serious concerns for the treating physician. We studied HFC as a cost-effective tool to predict platelet recovery. Methods This is a facility-based single-gate cross-sectional comparative diagnostic accuracy study. Patients presenting with febrile illness and undergoing dengue serology testing and complete blood count (CBC) test with HFC enumeration on the same day were analyzed. Dengue-positive patients with thrombocytopenia were serially monitored for both platelet count and HFC, along with other platelet parameters. Results A total of 515 febrile patients were included. The median age of the patients was 18 (11-31) years, and 281 (54.56%) patients were males. Overall, the lab positivity rate for dengue was 33% (170 patients out of 515). The HFC in dengue-positive patients ranged from 0 to 20.1%. The sensitivity and specificity of absolute HFC count at a cut-off of 0.02 were 74% and 32%, respectively; similarly, the sensitivity and specificity of HFC percentage at a cut-off of 0.2 were 92% and 25%, respectively. Eighty-nine (out of 170) dengue-positive patients had thrombocytopenia. In 15 cases, multiple serial HFC and platelet counts were available. The falling trend in HFC was followed by platelet recovery within 24 hours in 13 (86.6%) patients. Conclusion HFC serves as a sensitive but not specific marker for dengue infection in cases with febrile illness. The role of HFC in predicting platelet recovery in dengue cases should be further explored.

Per vaginal bleeding-an important but ignored feature of dengue

Background

Elderly individuals, those with comorbidities and pregnant women are at a higher risk of developing severe dengue and succumbing to their illness. However, an increased incidence of severe dengue and fatalities are seen in females of the reproductive age. As per vaginal (PV) bleeding is an important complication that has not been well characterized, we sought to determine the frequency, complications and disease outcomes in women who develop PV bleeding.

Methodology/Principal findings

288 adult female patients were recruited from the National Institute of Infectious Diseases Sri Lanka. All clinical features and laboratory investigations were recorded throughout the duration of hospital admission along with treatment received.28/288 (9.72%) reported PV bleeding, with 12/28 (42.85%) developing dengue haemorrhagic fever (DHF) compared to 65/260 (25%) of those who did not have bleeding.Women who developed PV bleeding were more likely to have developed DHF (OR 2.2, 95% CI 0.98 to 5.1, p=0.06), abdominal pain (OR=2.17, 95% CI = 0.99 to 4.69, p = 0.06), vomiting (OR= 2.0, 95% CI= 0.89 to 4.44, p= 0.10), diarhoea (OR= 4.35, 95% CI = 1.908 to 9.610, p= 0.0004) or evidence of any fluid leakage (OR= 1.98, 95% CI = 0.91 to 4.5, p = 0.11). Although not significant, those who had PV bleeding were more likely to have been given intravenous fluids, blood transfusions and colloids.

Conclusions

PV bleeding appears to associate with worse disease outcomes. The possible contribution of PV bleeding to higher incidence of severe dengue and fatality rates observed in many countries, should be further investigated.

Low-dose dengue virus 3 human challenge model: a phase 1 open-label study

Dengue human infection models present an opportunity to explore the potential of a vaccine, anti-viral or immuno-compound for clinical benefit in a controlled setting. Here we report the outcome of a phase 1 open-label assessment of a low-dose dengue virus 3 (DENV-3) challenge model (NCT04298138), in which nine participants received a subcutaneous inoculation with 0.5 ml of a 1.4 × 103 plaque-forming unit per ml suspension of the attenuated DENV-3 strain CH53489. The primary and secondary endpoints of the study were to assess the safety of this DENV-3 strain in healthy flavivirus-seronegative individuals. All participants developed RNAaemia within 7 days after inoculation with peak titre ranging from 3.13 × 104 to 7.02 × 108 genome equivalents per ml. Solicited symptoms such as fever and rash, clinical laboratory abnormalities such as lymphopenia and thrombocytopenia, and self-reported symptoms such as myalgia were consistent with mild-to-moderate dengue in all volunteers. DENV-3-specific seroconversion and memory T cell responses were observed within 14 days after inoculation as assessed by enzyme-linked immunosorbent assay and interferon-gamma-based enzyme-linked immunospot. RNA sequencing and serum cytokine analysis revealed anti-viral responses that overlapped with the period of viraemia. The magnitude and frequency of clinical and immunologic endpoints correlated with an individual's peak viral titre.

Diabetes mellitus as a risk factor for severe dengue fever and West Nile fever: A meta-analysis

BACKGROUND

Dengue fever (DF) and West Nile fever (WNF) have become endemic worldwide in the last two decades. Studies suggest that individuals with diabetes mellitus (DM) are at a higher risk of developing severe complications from these diseases. Identifying the factors associated with a severe clinical presentation is crucial, as prompt treatment is essential to prevent complications and fatalities. This article aims to summarize and assess the published evidence regarding the link between DM and the risk of severe clinical manifestations in cases of DF and WNF.

METHODOLOGY/PRINCIPAL FINDINGS

A systematic search was conducted using the PubMed and Web of Science databases. 27 studies (19 on DF, 8 on WNF) involving 342,873 laboratory-confirmed patients were included in the analysis. The analysis showed that a diagnosis of DM was associated with an increased risk for severe clinical presentations of both DF (OR 3.39; 95% CI: 2.46, 4.68) and WNF (OR 2.89; 95% CI: 1.89, 4.41). DM also significantly increased the risk of death from both diseases (DF: OR 1.95; 95% CI: 1.09, 3.52; WNF: OR 1.74; 95% CI: 1.40, 2.17).

CONCLUSIONS/SIGNIFICANCE

This study provides strong evidence supporting the association between DM and an increased risk of severe clinical manifestations in cases of DF and WNF. Diabetic individuals in DF or WNF endemic areas should be closely monitored when presenting with febrile symptoms due to their higher susceptibility to severe disease. Early detection and appropriate management strategies are crucial in reducing the morbidity and mortality rates associated with DF and WNF in diabetic patients. Tailored care and targeted public health interventions are needed to address this at-risk population. Further research is required to understand the underlying mechanisms and develop effective preventive and therapeutic approaches.

Biologics for dengue prevention: up-to-date

INTRODUCTION

Dengue is a worsening global public health problem. The vector-viral-host interactions driving the pathogenesis of dengue are multi-dimensional. Sequential dengue virus (DENV) infections with different DENV types significantly increase the risk of severe disease. Treatment is supportive in nature as there are no licensed anti-DENV antivirals or immuno-therapeutics. A single dengue vaccine has widely been licensed with two others in advanced clinical development. Dengvaxia® has been licensed in numerous countries but uptake has been slow as a result of safety signals noted in the youngest recipients and those who were dengue naïve at the time of vaccination.

AREAS COVERED

In this review, the current state of dengue vaccine and antiviral drug development will be discussed as well as new developments in controlled human infection models to support product development.

EXPERT OPINION

The world needs a safe and efficacious tetravalent dengue vaccine capable of protecting multiple different populations across a broad age range and different flavivirus immunologic backgrounds. Safe and effective antivirals are also needed to prevent or attenuate dengue disease in the unvaccinated, in cases of vaccine failure, or in high-risk populations.

Efficacy & safety of Carica papaya leaf extract (CPLE) in severe thrombocytopenia (≤30,000/μl) in adult dengue - Results of a pilot study

Severe thrombocytopenia in dengue often prompts platelet transfusion primarily to reduce bleeding risk. In India, about 11–43% of dengue patients report receiving platelet transfusions which is considered scarce and expensive especially in resource limited settings. Herein, we evaluated the efficacy and safety of Carica papaya leaf extract (CPLE) in the management of severe thrombocytopenia (≤30,000/μL) in dengue infection. 51 laboratory confirmed adult dengue patients with platelet counts ≤30,000/μL were randomly assigned to either treatment (n = 26) or placebo (n = 24) group. By day 3, CPLE treated patients reported significantly (p = 0.007) increased platelet counts (482%± 284) compared to placebo (331%±370) group. In the treatment group, fewer patients received platelet transfusions (1/26 v/s 2/24) and their median time for platelets to recover to ≥ 50,000/μL was 2 days (IQR 2–3) compared to 3 days (IQR 2–4) in placebo. Overall, CPLE was safe and well tolerated with no significant decrease in mean hospitalization days. Plasma cytokine profiling revealed that by day 3, mean percent increase in TNFα and IFNγ levels in treatment group was less compared to that observed in placebos; (TNFα: 58.6% v/s 127.5%; p = 0.25 and IFNγ: 1.93% v/s 62.6% for; p = 0.12). While a mean percent increase in IL-6 levels occurred in placebos (15.92%±29.93%) by day 3, a decrease was noted in CPLE group (12.95%±21.75%; p = 0.0232). Inversely, CPLE treated patients reported a mean percent increase compared to placebo by day 3 (143% ±115.7% v/s 12.03%± 48.4%; p = 0.006). Further, by day 3, a faster clearance kinetics of viral NS1 antigenemia occurred–mean NS1 titers in treatment group decreased to 97.3% compared to 88% in placebos (p = 0.023). This study demonstrates safety and efficacy of CPLE in increasing platelet counts in severe thrombocytopenia in dengue infections. A possible immunomodulatory and antiviral activity may be attributed to CPLE treatment. These findings merit validation in larger prospective studies.

Trial registration

Name of the registry: Clinical Trials Registry—India (CTRI)

Registration No.: CTRI-REF/2017/02/013314

Diagnostic accuracy and predictive value in differentiating the severity of dengue infection

OBJECTIVE

To review the diagnostic test accuracy and predictive value of statistical models in differentiating the severity of dengue infection.

METHODS

Electronic searches were conducted in the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, MEDLINE (complete), PubMed and Scopus. Eligible studies to be included in this review were cohort studies with participants confirmed by laboratory test for dengue infection and comparison among the different severity of dengue infection by using statistical models. The methodological quality of the paper was assessed by independent reviewers using QUADAS-2.

RESULTS

Twenty-six studies published from 1994 to 2017 were included. Most diagnostic models produced an accuracy of 75% to 80% except one with 86%. Two models predicting severe dengue according to the WHO 2009 classification have 86% accuracy. Both of these logistic regression models were applied during the first three days of illness, and their sensitivity and specificity were 91-100% and 79.3-86%, respectively. Another model which evaluated the 30-day mortality of dengue infection had an accuracy of 98.5%.

CONCLUSION

Although there are several potential predictive or diagnostic models for dengue infection, their limitations could affect their validity. It is recommended that these models be revalidated in other clinical settings and their methods be improved and standardised in future.

Pattern of dengue virus infections in adult patients from Sri Lanka

Background

Sri Lanka experienced its largest dengue epidemic in 2017. This study describes the disease pattern of adult dengue patients from two hospitals in Sri Lanka.

Methods

Demographic, clinical and investigation findings of adult dengue patients admitted to the two hospitals from June to August 2017 were collected and analysed.

Results

A total of 1167 patients (777 males [66.2%], mean age 32.9 y) were studied. There were 775 (66.4%) patients with dengue fever (DF), 334 (28.6%) with dengue haemorrhagic fever grade I, 54 (4.6%) with DHF grade II and 4 (0.3%) with DHF grade III. DHF was significantly associated with abdominal symptoms/signs and bleeding manifestations (p<0.001). A considerable variation in time of onset of the critical phase was noted (day 3, 11.9%; day 4-5, 63.1%; day 6, 16.2%; day ≥7, 8.7%). Significantly lower platelet and white blood cell counts and elevated transaminase levels were found in DHF than DF (p<0.001). Other complications included myocarditis (two patients) and mild renal impairment (three patients). None had neurological manifestations.

Conclusions

We found abdominal symptoms/signs, low platelet and white blood cell counts and high transaminase to be associated with DHF. The onset of the critical phase was variable and difficult to predict. Compiling data from various regions would help to understand disease patterns, which in turn would help in formulating evidence-based management guidelines and the allocation of limited health care resources.

Prevalence of chronic comorbidities in dengue fever and West Nile virus: A systematic review and meta-analysis

Background

Flavivirus diseases such as dengue fever (DENV), West Nile virus (WNV), Zika and yellow fever represent a substantial global public health concern. Preexisting chronic conditions such as cardiovascular diseases, diabetes, obesity, and asthma were thought to predict risk of progression to severe infections.

Objective

We aimed to quantify the frequency of chronic comorbidities in flavivirus diseases to provide an estimate for their prevalence in severe and non-severe infections and examine whether chronic diseases contribute to the increased risk of severe viral expression.

Methods

We conducted a comprehensive search in PubMed, Ovid MEDLINE(R), Embase and Embase Classic and grey literature databases to identify studies reporting prevalence estimates of comorbidities in flavivirus diseases. Study quality was assessed with the risk of bias tool. Age-adjusted odds ratios (ORs) were estimated for severe infection in the presence of chronic comorbidities.

Results

We identified 65 studies as eligible for inclusion for DENV (47 studies) and WNV (18 studies). Obesity and overweight (i.e., BMI> 25 kg/m², prevalence: 24.5%, 95% CI: 18.6–31.6%), hypertension (17.1%, 13.3–21.8%) and diabetes (13.3%, 9.3–18.8%) were the most prevalent comorbidities in DENV. However, hypertension (45.0%, 39.1–51.0%), diabetes (24.7%, 20.2–29.8%) and heart diseases (25.6%, 19.5–32.7%) were the most prevalent in WNV. ORs of severe flavivirus diseases were about 2 to 4 in infected patients with comorbidities such as diabetes, hypertension and heart diseases. The small number of studies in JEV, YFV and Zika did not permit estimating the prevalence of comorbidities in these infections.

Conclusion

Higher prevalence of chronic comorbidities was found in severe cases of flavivirus diseases compared to non-severe cases. Findings of the present study may guide public health practitioners and clinicians to evaluate infection severity based on the presence of comorbidity, a critical public health measure that may avert severe disease outcome given the current dearth of clear prevention practices for some flavivirus diseases.

Characteristics and predictors for gastrointestinal hemorrhage among adult patients with dengue virus infection: Emphasizing the impact of existing comorbid disease(s)

BACKGROUND

Gastrointestinal (GI) bleeding is a leading cause of death in dengue. This study aims to identify predictors for GI bleeding in adult dengue patients, emphasizing the impact of existing comorbid disease(s).

METHODS

Of 1300 adults with dengue virus infection, 175 (mean age, 56.5±13.7 years) patients with GI bleeding and 1,125 (mean age, 49.2±15.6 years) without GI bleeding (controls) were retrospectively analyzed.

RESULTS

Among 175 patients with GI bleeding, dengue hemorrhagic fever was found in 119 (68%) patients; the median duration from onset dengue illness to GI bleeding was 5 days. Gastric ulcer, erythematous gastritis, duodenal ulcer, erosive gastritis, and hemorrhagic gastritis were found in 52.3%, 33.3%, 28.6%, 28.6%, and 14.3% of 42 patients with GI bleeding who had undergone endoscopic examination, respectively. Overall, nine of the 175 patients with GI bleeding died, giving an in-hospital mortality rate of 5.1%. Multivariate analysis showed age ≥60 years (cases vs. controls: 48% vs. 28.3%) (odds ratio [OR]: 1.663, 95% confidence interval [CI]: 1.128-2.453), end stage renal disease with additional comorbidities (cases vs. controls: 1.7% vs. 0.2%) (OR: 9.405, 95% CI: 1.4-63.198), previous stroke with additional comorbidities (cases vs. controls: 7.4% vs. 0.6%) (OR: 9.772, 95% CI: 3.302-28.918), gum bleeding (cases vs. controls: 27.4% vs. 11.5%) (OR: 1.732, 95% CI: 1.1-2.727), petechiae (cases vs. controls: 56.6% vs. 29.1%) (OR: 2.109, 95% CI: 1.411-3.153), and platelet count <50×109 cells/L (cases vs. controls: 53.1% vs. 25.8%) (OR: 3.419, 95% CI: 2.103-5.558) were independent predictors of GI bleeding in patients with dengue virus infection.

CONCLUSIONS

Our study is the first to disclose that end stage renal disease and previous stroke, with additional comorbidities, were strongly significant associated with the risk of GI bleeding in patients with dengue virus infection. Identification of these risk factors can be incorporated into the patient assessment and management protocol of dengue virus infection to reduce its mortality.

Risk factors and clinical outcome of profound thrombocytopenia in adult patients with DENV infections

Severe thrombocytopenia is common in dengue virus (DENV) infections. However, studies focusing on the role of profound thrombocytopenia (PT) (nadir platelet counts ≤ 20 000/mm³) in DENV infections are scarce. This study aims to identify the associated features and outcome of DENV patients with PT. It involves 237 adult hospitalized patients who were DENV PCR positive. The presence of comorbidity (AOR = 4.625; 95% CI = 1.113-19.230), higher admission hematocrit (AOR = 1.213; 95% CI = 1.067-1.379), lower admission albumin (AOR = 0.870; 95% CI = 0.766-0.988) and lower admission platelets (AOR = 0.980; 95% CI = 0.969-0.991) was associated with platelets ≤ 20 000/mm³ in multivariate logistic regression. PT was not affected by DENV serotypes, coinfections and secondary DENV infections. Patients with PT had significantly higher risk of experiencing warning signs (AOR = 3.709, 95% CI = 1.089-12.634) and longer hospital stay (AOR = 1.943, 95% CI = 1.010-3.774). However, severe dengue disease, hemorrhagic manifestations and need for intensive care were not significantly associated with PT.