Febrile Phase Research Articles

Elevated TNF-α Induces Thrombophagocytosis by Mononuclear Cells in ex vivo Whole-Blood Co-Culture with Dengue Virus.

BackgroundInfection with dengue virus (DENV) causes hematological complications in dengue diseases characterized by thrombocytopenia accompanied by macrophage activation syndrome and hemophagocytosis in fatal patients.MethodsIn this study, we investigate the undefined mechanisms underlying the progression of thrombocytopenia caused by thrombophagocytosis based on an ex vivo whole-blood co-culture model of DENV infection for mimicking the acute febrile phase of infection.ResultsIn this model, complete blood count test showed a decrease in monocytes (p < 0.01), but not neutrophils nor other white blood cells, accompanied by a low thrombocyte count (p < 0.01) in DENV infection with a positive correlation (r = 0.636, p < 0.05). Furthermore, DENV exposure caused significant thrombophagocytosis in mononuclear cells (p < 0.05). Abnormal production of tumor necrosis factor (TNF)-α was highly associated with induction of thrombophagocytosis (r = 0.758, p < 0.01), decreased monocytes (r = −0.758, p < 0.01), and decreased thrombocyte (r = −0.728, p < 0.01). Neutralizing TNF-α considerably (p < 0.05) reversed such DENV-induced effects and was further validated by immunostaining-based flow cytometry analysis on mononuclear CD14 positive monocytes. Exogenous administration of TNF-α effectively caused thrombophagocytosis accompanied by decreased monocytes and thrombocytes, probably causing monocyte activation.ConclusionThese results demonstrate the potential pathogenesis of thrombocytopenia caused by TNF-α-induced thrombophagocytosis in monocytes during DENV infection.

Comparison of Axillary Digital and Infrared Forehead Thermometer

Introduction: Although digital thermometers have made the temperature recording easy, quick and safe, with the risk of mercury completely excluded, there is still a risk of transmission of infection from one individual to another. Infrared thermometers offer a non-touch, rapid and convenient method of temperature recording, with virtually no risk of disease transmission. We conducted a study to assess and compare temperature recordings from an infrared forehead thermometer and axillary digital thermometer during fever, and once the fever subsides. Methods: Hundred patients attending the out-patient department of Department of Pediatrics at Dr.B.R Ambedkar medical college and hospital from September 2019 to December 2019, or those admitted in the wards with a complaint of fever were screened using two techniques – Axillary temperature recording using a digital thermometer and a forehead temperature was recorded using a non-contact infrared forehead thermometer. Patients were given antipyretics to treat the fever and temperature was again recorded once the fever subsided using the same method. Two medical personnel were trained to screen and record the respective findings from each method and they were blinded from the other outcome of other recording. Results: The mean IFR temperature measured in the febrile phase was 100.85 (± 0.76), which was significantly higher than the mean AD temperature, 100.21 (± 0.74). (p-value &lt;.0001). In the afebrile phase as well, the mean IFR temperature was significantly higher than the mean AD temperature. Conclusion: IFR thermometers do provide an advantage of no-touch technique over the digital thermometer. However, as the results showed a weak correlation between IFR and axillary digital recordings, it is suggested that IFR thermometers be used for screening of children for fever as it decreases the contact and reduces the infection.

Correlation of Dengue Warning Signs during Febrile Phase with Rotational Thromboelastometry, Cortisol and Feritin.

Dengue mortality remains high despite monitoring against warning signs (WS). The associations of WS at febrile phase (FP) and hemorrhage at defervescence with the levels and kinetics of ROTEM, platelet count, cortisol, and ferritin were analyzed. Patients with confirmed dengue serology and WS in two centers were screened (n = 275) and 62 eligible patients were recruited prospectively over 9 months. “Vomiting” was the commonest WS (62.9%), with shortened clotting time (CT) INTEM (p = 0.01). “Hematocrit increase” showed significant prolonged CT INTEM, EXTEM, and FIBTEM (p < 0.05). “Platelet decrease” showed reduced platelet function and reduced clot amplitude at 10 min (A10) and maximum clot firmness (MCF) in INTEM and EXTEM (p < 0.001). The kinetics were reduced in platelet count, CT EXTEM, and cortisol (p < 0.05) but increased in CT INTEM (p = 0.03). At FP, “vomiting”, “hematocrit increase”, and “platelet decrease” demonstrated impaired CT, clot strengths A10/MCF and platelet functions. Majority (60/62, 96.7%) had non-severe outcomes, consistent with increase in cortisol kinetics. In conclusion, “vomiting”, “hematocrit increase” and “platelet decrease” at FP correlated with ROTEM. No conclusion could be made further regarding ferritin and cortisol. Larger study is required to study “hematocrit increase” with ROTEM as a potential marker for hemorrhage.

Prognostic indicators associated with progresses of severe dengue.

BackgroundDengue usually progress abnormally, especially in the critical phase. The main causes of death were shock, severe bleeding and organ failure. The aim of our study was to evaluate prognostic indicators of severe dengue according to the phases of the disease progression.MethodsA cross-sectional study was conducted from July to December 2017 at the National Hospital for Tropical Diseases and the Hospital for Tropical Diseases of Ho Chi Minh City. 326 patients, aged 6 years and over, including 99/326 patients with severe dengue and 227/326 patients with non-severe dengue, hospitalized in the first 3 days of illness, confirmed Dengue virus by the RT-PCR assay have been registered for the study. Clinical manifestations were monitored daily. The hematocrit, white blood cells, platelet, serum albumin, ALT, AST, bilirubin, prothrombin time (PT%, PTs), fibrinogen, aPTT, INR and creatinine were evaluated at two times: febrile phase and critical phase.ResultsIndependent factors associated with severe dengue were identified on multivariate logistic regression models. During the first 3 days of the disease, the prognostic indicators were platelet count ≤ 100 G/L (OR = 2.2; 95%CI: 1.2–3.9), or serum albumin < 35 g/L (OR = 3.3; 95%CI: 1.8–6.1). From day 4–6, the indicator were AST > 400 U/L (OR = 3.0; 95%CI: 1.1–7.9), ALT > 400 U/L (OR = 6.6; 95%CI: 1.7–24.6), albumin < 35 g/L (OR = 3.0; 95%CI: 1.5–5.9), and bilirubin total >17 μmol/L (OR = 4.6; 95%CI: 2.0–10.4).ConclusionTo predict the risk of patients with severe dengue, prognostic laboratory indicators should be indicated consistent with the progression of the disease. During the first 3 days of illness, prognostic indicators should be platelet count, or serum albumin. From the 4th - 6th day of illness, prognostic indicators should be AST, ALT, albumin, or bilirubin total.

A Population of CD4+CD8+ Double-Positive T Cells Associated with Risk of Plasma Leakage in Dengue Viral Infection.

According to the WHO 2009 classification, dengue with warning signs is at the risk of developing severe form of dengue disease. One of the most important warning signs is plasma leakage, which can be a serious complication associated with higher morbidity and mortality. We report that the frequency of CD4+CD8+ double-positive (DP) T cells is significantly increased in patients at risk of developing plasma leakage. Transcriptomic analysis demonstrated that CD4+CD8+ DP cells were distinct from CD4+ Single Positive (SP) T cells but co-clustered with CD8+ SP cells, indicating a largely similar transcriptional profile. Twenty significant differentially expressed (DE) genes were identified between CD4+CD8+ DP and CD8+ SP cells. These genes encode OX40 and CCR4 proteins as well as other molecules associated with cell signaling on the cell surface (NT5E, MXRA8, and PTPRK). While comparing the profile of gene expression in CD4+CD8+ DP cells from patients with and without warning signs of plasma leakage, similar expression profile was observed, implying a role of CD4+CD8+ DP cells in plasma leakage through a quantitative increase rather than functional alteration. This study provided novel insight into the host immune response during the acute febrile phase of DENV infection and the role of CD4+CD8+ DP T cells in the pathogenesis of plasma leakage.

The symptomatology of fever: A step towards qualitative definition of fever.

The old definitions of fever are based on cross-sectional surveys of the population without analyzing the associated symptomatology as fever is a sign, not symptom. Therefore, a longitudinal follow-up study is the need of hour to analyze associated symptoms with fever. In a longitudinal study over one year, 196 participants recorded three temperature readings daily, one after waking up, one between 12 and 3 PM, one before sleeping, and filled the symptomatology questionnaire in a thermometry diary. Per protocol analysis was done for febrile participants (n = 144). Fatigue (50.3%), warmth (47.3%), headache/head heaviness (47.0%), feeling malaise/general weakness (46.7%), loss of appetite (46.5%), muscle cramps/muscle aches (45.6%), chills/shivering (44.6%), increased sweating (43.0%), nausea (42.5%), irritability (38.9%), increased breathing rate (37.1%), and restlessness/anxiety/palpitations (36.5%) were the symptoms maximally seen during the febrile phase. A higher number of associated symptoms are associated with higher temperature readings. Dehydration suggested the numerically highest temperature values (100.86 ± 1.70°F) but seen in few febrile patients. Incorporation of symptom analysis in febrile patients is the need of the hour. Fatigue and warmth are found to be the most prevalent symptoms during febrile phase. Associated symptoms can help in predicting the intensity of fever also.

Quantitative Definition of Fever Needs a Change: A Longitudinal Study from the Hospital Workers and their Family Members

Introduction: The age-old definition of fever was derived using cross-sectional population surveying utilising old techniques without considering symptomatology. However, the diagnosis of fever must be made only in the presence of associated symptoms that can distinguish it from the mere asymptomatic physiologic rise of temperature. Aim: Analysis of symptoms to re-define the cut-off of fever based on symptomatology. Materials and Methods: A longitudinal study on the healthy population of Uttarakhand, India was conducted and the population was followed up from July 2019 to September 2020. Healthy staff and students of All India Institute of Medical Sciences (AIIMS), and their family members between 4-100 years of age were chosen. Participants were advised to self-monitor oral temperature with a standard digital thermometer in either left or right sublingual pocket and record it in the thermometry diary. The study was considered complete if the participant had all the three phases of the study (i.e., prefebrile, febrile, and postfebrile phases) or completed the duration of the study. The febrile phase was defined when the participants subjectively ‘felt feverish’. Associated symptoms like fatigue, warmth, headache, and feeling malaise were also recorded. Results: Mean age of the participants was 24.24±5.92 years, and 52.1% (75) were males. Per protocol analysis was done for febrile participants (n=144, temperature recordings=6544). The mean febrile phase temperature was 100.25±1.440 F. A temperature of 99.10 F had maximum diagnostic accuracy for feeling feverish (98.2%), along with one (98.3%) or two (99%) associated symptoms. Summer and spring months showed higher temperatures (100.38±1.44 v/s 99.80±1.49, p-value&lt;0.001), whereas no significant temperature difference could be noted amongst the genders. Conclusion: Based on the findings of this study, the revised temperature cut-off to define fever should be 99.10 F along with one or two associated symptoms.

Automated complete blood count profile as a probable indicator of dengue fever severity in children

Background: Dengue is now endemic in more than 100 tropical and subtropical countries. Ninety percent of dengue hemorrhagic fever occurs in children <15 years of age. Leukopenia and thrombocytopenia near the end of the febrile phase are the common findings in dengue fever. Aims and Objectives: (1) To see any significant correlations between various hematological parameters with severity of dengue and (2) to see the shift in the values (increase/decrease) of platelet indices in dengue patients. Materials and Methods: One hundred and twenty patients admitted either with laboratory report of seropositive dengue or with dengue-like symptoms and who were found to be dengue positive after admission were included in the study. Complete hemogram including platelet indices was evaluated by an automated cell counter. Clinical examinations were performed in detail with special reference to the presence of warning signs such as vomiting, lethargy, pain abdomen, bleeding, and ascites. Results: Total leukocyte count, platelet distribution width, and mean platelet volume were not significantly different in patients with warning signs from those without it. The level of mean hematocrit was significantly higher and the mean plateletcrit was significantly lower in dengue with warning signs. Conclusions: Simultaneous measurement of complete blood count and platelet indices can provide us a valid instrument for the measurement of dengue disease severity and an insight into the potential etiology that resulted in change in platelet indices.

Study of Cardiac Manifestation in Patients with Seropositive Dengue Fever and to Find Correlation with Subclinical Cardiac Involvement

Objective: The main objective of the present study was to observe the electrocardiogram (ECG) changes in dengue fever and to find correlation with subclinical cardiac involvement. Methods: This was an observational, prospective, non-randomized study. High grade fever for one to five days diagnosed as dengue infection later confirmed by dengue tests (NS1, IgG and IgM ELISA) were included in this study. Prior to the commencement of the study informed consent was taken from all the participants. With 12 lead ECG taken during the febrile phase of dengue fever randomly selected serologically confirmed cases of dengue fever were evaluated at an interval of 24 hrs. for a total of five days. On the day of admission when the patient was afebrile, echocardiography was done. Plasma leakage was diagnosed by presence of any one of four: subcutaneous oedema (pedal oedema, facial puffiness) or pleural effusion or pericardial effusion or ascites. Result: A total 80 patients who were admitted to hospital during study periods due to symptoms of dengue fever and IgM dengue positive status were included in this study. Among this total population of 80 patients (N=80) 48 were male and 32 were female. Out of these, majority were diagnosed as DF 52 (65%), 23 (29%) were diagnosed as DHF and rest only 5 (6%) were diagnosed as DSS. Total 54 patients were found to have normal ECG among which 35 were having dengue fever, 16 were having DHF and 3 were having DSS. Total 2 patients were diagnosed to have left ventricular hypertrophy among which one had dengue fever and rest two had DHF. ST depression was observed in total 7 patients in which 5 were had dengue fever and 2 were had DHF. Relative bradycardia was found in 14, tall t waves in 2 and ventricular ectopics in 1 patient (table 2). Abnormal ECG findings were compared using Chi-square test and were found to be statistically significant (P &lt; 0.05) in dengue fever and DHF. There was statistically significant correlation between ECG abnormalities and abdominal pain and mucosal bleed. The presence of plasma leakage were observed among 77 (96.3%) patients. Proportion of echocardiography abnormalities were higher among patients with plasma leak 6 (30%) as compared to without plasma leak 9 (15%), this difference was not found to be statistically significant Conclusion: In all type of Dengue infections incidence of cardiac involvement was quite high. Due to the overlapping clinical manifestations such as capillary leak associated with DENV infection, tachycardia, pulmonary edema, and hypotension as well as due to the low index of clinical suspicion cardiac involvement in dengue fever is often underdiagnosed. Keywords: Cardiac manifestation, dengue infection, echocardiography, electrocardiography.

Leaky Gut Syndrome Is Associated with Endotoxemia and Serum (1→3)-β-D-Glucan in Severe Dengue Infection.

The hallmark of severe dengue infection is the increased vascular permeability and hemodynamic alteration that might be associated with an intestinal permeability defect. However, the mechanisms underlying the gastrointestinal-related symptoms of dengue are not well characterized. A prospective observational study was conducted on patients with dengue who were categorized according to: (i) febrile versus critical phase and (ii) hospitalized patients with versus without the warning signs to evaluate the gut barrier using lactulose-to-mannitol excretion ratio (LEMR). Serum endotoxins, (1→3)-β-D-glucan (BG), and inflammatory parameters were measured. A total of 48 and 38 patients were enrolled in febrile illness and critical phase, respectively, while 22 and 64 patients presented with or without the warning signs, respectively. At enrollment, a positive LEMR test was found in 20 patients (91%) with warning signs, regardless of phase of infection. Likewise, serum endotoxins and BG, the indirect biomarkers for leaky gut, prominently increased in patients who developed severe dengue when compared with the non-severe dengue (endotoxins, 399.1 versus 143.4 pg/mL (p < 0.0001); BG, 123 versus 73.8 pg/mL (p = 0.016)). Modest impaired intestinal permeability occurred in dengue patients, particularly those with warning signs, and were associated with endotoxemia and elevated BG. Thus, leaky gut syndrome might be associated with severity of dengue infection.

Comprehensive investigation of fever cases enrolled during 2019 dengue outbreaks from three hyperendemic regions of North 24 Parganas district of West Bengal, India.

For the past several decades, dengue fever has been emerging in epidemic proportions in several regions of the world. During August-September 2019, an increasing number of fever cases were being reported from some areas of North 24 Parganas district of West Bengal, India. Accordingly, outbreak investigation of fever cases from these affected areas of Bongoan, Barasat, and Habra was carried out. To characterize clinical and biochemical features of fever cases as well as to investigate the utility of CRP as a Dengue severity marker in resource-limited settings. We systematically enrolled 108 patients from the affected region of North 24 Parganas. Standard diagnostic assays along with routine serological and biochemical parameters were performed. Of the 108 patients, 77 (71%) were confirmed with Dengue infection followed by 22 (20%) DENV seronegative and 9 (8%) coinfected DENV cases. Among the 77 confirmed Dengue patients, 53 (69%) had primary infection while 24 (31%) had secondary infection. Among the DENV clinical symptoms, fever (r = 0.50; p = 0.004), headache (r = 0.40; p = 0.03) and abdominal pain (r = -0.40; p = 0.02) were found to bear significant correlation with DENV viral load. The predominant circulating serotype was found to be DENV2. CRP Dengue severity cut-off level of 10.15 mg/L (AUC: 0.85; 86% sensitivity, 77% specificity) was obtained. CRP had correlation with viral load (r = 0.4, p = 0.05) within febrile phase of infection. The performance of biomarkers can be influenced by local epidemiology, geography, and several patient factors, therefore, CRP Dengue severity cut-off value may be region-specific. This study for the first time attempts to estimate CRP Dengue severity cut-off value based on routine immunoturbidometric evaluation from Dengue Hyperendemic zones of North 24 Parganas, West Bengal, Eastern India.

Unique characteristics of new complete blood count parameters, the Immature Platelet Fraction and the Immature Platelet Fraction Count, in dengue patients.

The advanced platelet parameters Immature Platelet Fraction and Immature Platelet Fraction Count have been implemented in clinical practice as measures of thrombopoietic activity, mainly in hematologic disorders that cause thrombocytopenia. The purpose of this observational study was to examine thrombopoiesis as reflected by these 2 new CBC parameters in patients infected with dengue. The study was conducted in infectious disease referral hospital in Metro Manila, the Philippines. We enrolled hospitalized patients at admission who were diagnosed with acute dengue or community acquired bacterial infection (CABI). Immature Platelet Fraction (IPF) and Immature Platelet Fraction Count were evaluated at admission and during hospitalization. A total of 606 patients were enrolled from May 1, 2017 to June 1, 2018. The participants consisted of 152 patients with dengue infection, 180 confirmed CABI, and 274 suspected CABI patients. At admission, the percent IPF (IPF%) of the patients with dengue was significantly higher than that of the confirmed CABI patients (median 3.7% versus 1.9%; p <0.001). In a time course evaluation, there was no significant difference of IPF% between the patients with dengue infection and the confirmed CABI patients in the febrile phase (median 1.9% versus 2.4%; p = 0.488), however, the IPF% of the patients with dengue infection increased to be significantly higher than that of the confirmed CABI patients in the critical phase (median 5.2% versus 2.2%; p <0.001). Our study elucidated the unique characteristics and time-course trends of IPF percent and number (IPF#) in the patients with dengue infection. IPF% and IPF# are potentially valuable parameters in dengue and further investigation is required for the optimal use in clinical practice.

Lung Ultrasound Findings of Patients with Dengue Infection: A Prospective Observational Study.

Lung ultrasound (LUS) is a more sensitive method of detecting pathological pulmonary changes than chest X-ray. Therefore, LUS for patients with dengue could be an important tool for the early detection of pleural effusions and pulmonary edema signifying capillary plasma leakage, which is the hallmark of severe dengue pathophysiology. We conducted a prospective observational study of pulmonary changes identifiable with LUS in dengue patients admitted to the Hospital for Tropical Diseases in Mahidol University, Bangkok, and the Bamrasnaradura Infectious Diseases Institute, Nonthaburi, Thailand. The LUS findings were described according to standard criteria, including the presence of A, B1, B2, and C patterns in eight chest regions and the presence of pleural effusions. From November 2017 to April 2018, 50 patients with dengue were included in the study. LUS was performed during the febrile phase for nine patients (18%) and during the critical-convalescence phase for 41 patients (82%). A total of 33 patients (66%) had at least one abnormality discovered using LUS. Abnormal LUS findings were observed more frequently during the critical-convalescence phase (N = 30/41; 73%) than during the febrile phase (N = 3/9; 33%) (P = 0.047). Abnormal aeration patterns were observed in 31 patients (62%). Only B patterns with only multiple B lines were observed in 21 patients (42%); of these patients, three had already exhibited B patterns during the febrile phase (N = 3). C patterns (N = 10; 24%), pleural effusion (N = 10; 24%), and subpleural abnormalities (N = 11; 27%) were observed only during the critical-convalescence phase. LUS can detect signs of capillary leakage, including interstitial edema and pleural effusions, early during the course of dengue.

Combination of inflammatory and vascular markers in the febrile phase of dengue is associated with more severe outcomes.

Early identification of severe dengue patients is important regarding patient management and resource allocation. We investigated the association of 10 biomarkers (VCAM-1, SDC-1, Ang-2, IL-8, IP-10, IL-1RA, sCD163, sTREM-1, ferritin, CRP) with the development of severe/moderate dengue (S/MD). We performed a nested case-control study from a multi-country study. A total of 281 S/MD and 556 uncomplicated dengue cases were included. On days 1-3 from symptom onset, higher levels of any biomarker increased the risk of developing S/MD. When assessing together, SDC-1 and IL-1RA were stable, while IP-10 changed the association from positive to negative; others showed weaker associations. The best combinations associated with S/MD comprised IL-1RA, Ang-2, IL-8, ferritin, IP-10, and SDC-1 for children, and SDC-1, IL-8, ferritin, sTREM-1, IL-1RA, IP-10, and sCD163 for adults. Our findings assist the development of biomarker panels for clinical use and could improve triage and risk prediction in dengue patients. This study was supported by the EU's Seventh Framework Programme (FP7-281803 IDAMS), the WHO, and the Bill and Melinda Gates Foundation.

The Natural History of Aerosolized Francisella tularensis Infection in Cynomolgus Macaques.

Tularemia is a severe, zoonotic infection caused by the Gram-negative bacterium Francisella tularensis. Inhalation results in a rapid, severe bacterial pneumonia and sepsis, which can be lethal. Because the cynomolgus macaque is the accepted nonhuman primate model for tularemia, we conducted a natural history study of pneumonic tularemia by exposing macaques to target inhaled doses of 50, 500, or 5000 colony forming units (CFU) of F. tularensis subsp. tularensis SCHU S4. Two animals within the 50 CFU group (calculated doses of 10 and 11 CFU) survived the challenge, while the remainder succumbed to infection. Exposure of cynomolgus macaques to aerosolized SCHU S4 resulted in fever, anorexia, increased white blood cell counts, lymphopenia, thrombocytopenia, increased liver enzymes, alterations in electrocardiogram (ECG), and pathological changes typical of infection with F. tularensis, regardless of the challenge dose. Blood pressure dropped during the febrile phase, particularly as temperature began to drop and macaques succumbed to the disease. ECG analysis indicated that in 33% of the macaques, heart rate was not elevated during the febrile phase (Faget’s sign; pulse-temperature disassociation), which has been reported in a similar percentage of human cases. These results indicated that infection of cynomolgus macaques with aerosolized F. tularensis results in similar disease progression and outcome as seen in humans, and that cynomolgus macaques are a reliable animal model to test medical countermeasures against aerosolized F. tularensis.

Increased TNF-α Initiates Cytoplasmic Vacuolization in Whole Blood Coculture with Dengue Virus.

During the acute febrile phase of dengue virus (DENV) infection, viremia can cause severe systemic immune responses accompanied by hematologic disorders. This study investigated the potential induction and mechanism of the cytopathic effects of DENV on peripheral blood cells ex vivo. At one day postinfection, there was viral nonstructural protein NS1 but no further virus replication measured in the whole blood culture. Notably, DENV exposure caused significant vacuolization in monocytic phagocytes. With a minor change in the complete blood cell count, except for a minor increase in neutrophils and a significant decrease in monocytes, the immune profiling assay identified several changes, particularly a significant reduction in CD14-positive monocytes as well as CD11c-positive dendritic cells. Abnormal production of TNF-α was highly associated with the induction of vacuolization. Manipulating TNF-α expression resulted in cytopathogenic effects. These results demonstrate the potential hematological damage caused by ex vivo DENV-induced TNF-α.

Risk predictors of progression to severe disease during the febrile phase of dengue: a systematic review and meta-analysis

SummaryBackgroundThe ability to accurately predict early progression of dengue to severe disease is crucial for patient triage and clinical management. Previous systematic reviews and meta-analyses have found significant heterogeneity in predictors of severe disease due to large variation in these factors during the time course of the illness. We aimed to identify factors associated with progression to severe dengue disease that are detectable specifically in the febrile phase.MethodsWe did a systematic review and meta-analysis to identify predictors identifiable during the febrile phase associated with progression to severe disease defined according to WHO criteria. Eight medical databases were searched for studies published from Jan 1, 1997, to Jan 31, 2020. Original clinical studies in English assessing the association of factors detected during the febrile phase with progression to severe dengue were selected and assessed by three reviewers, with discrepancies resolved by consensus. Meta-analyses were done using random-effects models to estimate pooled effect sizes. Only predictors reported in at least four studies were included in the meta-analyses. Heterogeneity was assessed using the Cochrane Q and I2 statistics, and publication bias was assessed by Egger's test. We did subgroup analyses of studies with children and adults. The study is registered with PROSPERO, CRD42018093363.FindingsOf 6643 studies identified, 150 articles were included in the systematic review, and 122 articles comprising 25 potential predictors were included in the meta-analyses. Female patients had a higher risk of severe dengue than male patients in the main analysis (2674 [16·2%] of 16 481 vs 3052 [10·5%] of 29 142; odds ratio [OR] 1·13 [95% CI 1·01–1·26) but not in the subgroup analysis of studies with children. Pre-existing comorbidities associated with severe disease were diabetes (135 [31·3%] of 431 with vs 868 [16·0%] of 5421 without; crude OR 4·38 [2·58–7·43]), hypertension (240 [35·0%] of 685 vs 763 [20·6%] of 3695; 2·19 [1·36–3·53]), renal disease (44 [45·8%] of 96 vs 271 [16·0%] of 1690; 4·67 [2·21–9·88]), and cardiovascular disease (nine [23·1%] of 39 vs 155 [8·6%] of 1793; 2·79 [1·04–7·50]). Clinical features during the febrile phase associated with progression to severe disease were vomiting (329 [13·5%] of 2432 with vs 258 [6·8%] of 3797 without; 2·25 [1·87–2·71]), abdominal pain and tenderness (321 [17·7%] of 1814 vs 435 [8·1%] of 5357; 1·92 [1·35–2·74]), spontaneous or mucosal bleeding (147 [17·9%] of 822 vs 676 [10·8%] of 6235; 1·57 [1·13–2·19]), and the presence of clinical fluid accumulation (40 [42·1%] of 95 vs 212 [14·9%] of 1425; 4·61 [2·29–9·26]). During the first 4 days of illness, platelet count was lower (standardised mean difference −0·34 [95% CI −0·54 to −0·15]), serum albumin was lower (−0·5 [–0·86 to −0·15]), and aminotransferase concentrations were higher (aspartate aminotransferase [AST] 1·06 [0·54 to 1·57] and alanine aminotransferase [ALT] 0·73 [0·36 to 1·09]) among individuals who progressed to severe disease. Dengue virus serotype 2 was associated with severe disease in children. Secondary infections (vs primary infections) were also associated with severe disease (1682 [11·8%] of 14 252 with vs 507 [5·2%] of 9660 without; OR 2·26 [95% CI 1·65–3·09]). Although the included studies had a moderate to high risk of bias in terms of study confounding, the risk of bias was low to moderate in other domains. Heterogeneity of the pooled results varied from low to high on different factors.InterpretationThis analysis supports monitoring of the warning signs described in the 2009 WHO guidelines on dengue. In addition, testing for infecting serotype and monitoring platelet count and serum albumin, AST, and ALT concentrations during the febrile phase of illness could improve the early prediction of severe dengue.FundingWellcome Trust, National Institute for Health Research, Collaborative Project to Increase Production of Rural Doctors, and Royal Thai Government.

Clinical features and outcomes of neonatal dengue at the Children's Hospital 1, Ho Chi Minh, Vietnam.

Objectives Neonatal dengue has been reported in the literature with contradictory findings of clinical characteristics and diagnosis; thereby, misdiagnosis of neonatal dengue has been frequently reported. We aim to delve into the epidemiology, clinical features, and outcomes of neonatal dengue, thus avoid misdiagnosis and obtain early intervention. Study design A retrospective study was conducted at Children's Hospital 1, Ho Chi Minh, Vietnam with laboratory-confirmed dengue in neonates by positive viral antigen nonstructural protein one rapid test (NS1) and positive IgM antibody for dengue by MAC-ELISA. Results We have included 32 neonates in this study with 25% cases were misdiagnosed with neonatal sepsis, and 12.5% cases were misdiagnosed with neonatal immune thrombocytopenia at the beginning. The median time between the first day of the mother's onset of fever and childbirth was -1 days (IQR: -2, 2). The patient's clinical manifestation included: petechiae 87.5% (28/32), pharyngeal mucosal hemorrhage 6.3% (2/32), and hepatomegaly occurred 75% (24/32). In the febrile phase (day of illness 1-3), the mean white blood cell (WBC) counts were 7800 ± 800/mm3 and platelets were 97,111 ± 37,826/mm3. In the critical phase (day of illness 4-6), the mean WBC counts were 13,400 ± 2800/mm3, and platelets were 30,100 ± 5749/mm3. All mothers (100%) had laboratory-confirmed dengue by NS1 positive in the perinatal period. Conclusions The findings emphasize that early diagnosis of neonatal dengue should be based on a history of maternal illness, NS1 rapid test, and clinical presentation such as petechiae, hepatomegaly, and low platelet counts in the febrile phase.

Physiological and immunological changes in the brain associated with lethal eastern equine encephalitis virus in macaques.

Aerosol exposure to eastern equine encephalitis virus (EEEV) can trigger a lethal viral encephalitis in cynomolgus macaques which resembles severe human disease. Biomarkers indicative of central nervous system (CNS) infection by the virus and lethal outcome of disease would be useful in evaluating potential medical countermeasures, especially for therapeutic compounds. To meet requirements of the Animal Rule, a better understanding of the pathophysiology of EEEV-mediated disease in cynomolgus macaques is needed. In this study, macaques given a lethal dose of clone-derived EEEV strain V105 developed a fever between 2–3 days post infection (dpi) and succumbed to the disease by 6 dpi. At the peak of the febrile phase, there was a significant increase in the delta electroencephalography (EEG) power band associated with deep sleep as well as a sharp rise in intracranial pressure (ICP). Viremia peaked early after infection and was largely absent by the onset of fever. Granulocytosis and elevated plasma levels of IP-10 were found early after infection. At necropsy, there was a one hundred- to one thousand-fold increase in expression of traumatic brain injury genes (LIF, MMP-9) as well as inflammatory cytokines and chemokines (IFN-γ, IP-10, MCP-1, IL-8, IL-6) in the brain tissues. Phenotypic analysis of leukocytes entering the brain identified cells as primarily lymphoid (T, B, NK cells) with lower levels of infiltrating macrophages and activated microglia. Massive amounts of infectious virus were found in the brains of lethally-infected macaques. While no infectious virus was found in surviving macaques, quantitative PCR did find evidence of viral genomes in the brains of several survivors. These data are consistent with an overwhelming viral infection in the CNS coupled with a tremendous inflammatory response to the infection that may contribute to the disease outcome. Physiological monitoring of EEG and ICP represent novel methods for assessing efficacy of vaccines or therapeutics in the cynomolgus macaque model of EEEV encephalitis.

Comparison of Dengue Predictive Models Developed Using Artificial Neural Network and Discriminant Analysis with Small Dataset

In Indonesia, dengue has become one of the hyperendemic diseases. Dengue consists of three clinical phases—febrile phase, critical phase, and recovery phase. Many patients have died in the critical phase due to the lack of proper and timely treatment. Therefore, we developed models that can predict the severity level of dengue based on the laboratory test results of the corresponding patients using Artificial Neural Network (ANN) and Discriminant Analysis (DA). In developing the models, we used a very small dataset. It is shown that ANN models developed using logistic and hyperbolic tangent activation function with 70% training data yielded the highest accuracy (90.91%), sensitivity (91.11%), and specificity (95.51%). This is the proposed model in this research. The proposed model will be able to help physicians in predicting the severity level of dengue patients before entering the critical phase. Furthermore, it will ease physicians in treating dengue patients early, so fatal cases or deaths can be avoided.