Why are children highly vulnerable to dengue infection

@#The prevalence of dengue infection poses a great public health concern among people living in tropical and subtropical countries like the Philippines. Just recently in 2019, the Philippines had a dengue virus (DENV) outbreak where nearly half of the mortalities were children between 5 and 9 years of age, and around 73% of confirmed DENV cases were under the age of 19. Children are disproportionately affected and are considered to be highly vulnerable to severe dengue infection compared to adults due to several factors. These include: immunological differences--poorly developed immune systems, making them more susceptible to the virus; smaller body sizes and weight means that they are more likely to experience severe symptoms; and their tendency to play outdoors, make them more exposed to mosquito bites. Hence, this article provides an overview of the current understanding for the vulnerability of children to severe dengue infection compared to adults

Maternal & perinatal outcome of fever in pregnancy in the context of dengue - A retrospective observational study

Background & objectives: Pregnant women with dengue infection may be at increased risk of adverse maternal-foetal outcomes. This study was conducted to assess the maternal and perinatal outcomes in women who presented with fever and diagnosed to have dengue infection during pregnancy. Methods: A retrospective observational study was conducted on pregnant women admitted with fever, in a tertiary referral centre in South India, during January 2015 to December 2018. We compared outcomes of women diagnosed with dengue with that of women without dengue. The study outcomes included pre-term birth, stillbirth, low-birth weight (LBW), maternal mortality and thrombocytopenia. Results: During the study period, there were six maternal deaths following complications from dengue infection. Higher rates of thrombocytopenia (24.7% vs. 14.6%, P=0.02) were noted among those with recent dengue infection. The risk of still birth was 2.67 [95% confidence interval (CI) 1.09, 6.57], LBW [risk ratio (RR) 1.13, 95% CI 0.87, 1.45] and pre-term birth (RR 1.33, 95% CI 0.89, 1.97) among the cases. Interpretation & conclusions: Occurrence of adverse maternal and foetal outcomes was increased in pregnant women with fever diagnosed with dengue infection. Future studies are needed to formulate the optimum monitoring and treatment strategies in pregnant women, where dengue can have additive adverse effects to other obstetric complications.

A study of various hepatic manifestations in dengue fever and their correlation with severity of dengue fever

Background: Hepatic involvement in Dengue is known with protean of manifestations ranging from hepatomegaly, elevated liver enzymes to fulminant hepatic failure. Aim of the study was to study the hepatic manifestations in children with dengue illness.Methods: This is a prospective Study with 60 Patients hospitalized with Dengue infection (Seropositive for Dengue). Dengue Seropositive patients are selected and examined for Hepatomegaly and Jaundice and subjected to complete blood count and Liver function tests were analysed.Results: Of 60 serologically confirmed cases hospitalized with dengue, were classified into (i)(DF), (ii) DHF I (iii) DHF II (iv) DHF III and (v) DHF IV.' In our study, upon 60 seropositive cases were reported at our hospital during the study period of which 18 were DF, 12 were DHF I, 15 were DHFII, 8 were DHF III and 7 were DHF IV respectively. The Hematocrit levels were raised 20% from the baseline in four classes of Dengue and not raised in DF. Most commonly occurred in age group of 5-7 years. Hepatomegaly was the commonest clinical sign seen. Thrombocytopenia was seen in 88% of all cases. Serum total bilirubin was raised in 10% of subjects with severe dengue infection in DHF III and DHF IV. Serum SGOT and SGPT was raised in 63.3% and 56.7% of patients with dengue of all classes including DF respectively. Thrombocytopenia occurred in 75% of patients with dengue fever, 98% with warning signs and 100% in severe dengue.Conclusions: In developing country like India, incidence of dengue outbreaks is increasing. Hepatic involvement of varying degrees have been reported. As hepatic dysfunction in dengue is transient and reversible, early identification of the same would help to reduce life threatening complications. The role of hepato protective drugs in reducing morbidity and mortality should be analysed by further studies.

Clinical Utility of Extended Monocytes Parameters as a Screening Tool in Suspected Dengue Infection

@# Increased monocyte percentage and monocyte anisocytosis were suggested as new markers for dengue fever detection. This study aims to investigate and evaluate monocyte volume standard deviation (MoV-SD) and monocyte percentage (Mono %) parameters using Coulter automated haematology analyser as screening parameters in discriminating between dengue infection and other febrile illness. Methods: A cross-sectional laboratory analysis using suspected dengue fever patients were included in this study. The study was conducted in the Department of Pathology, Hospital Tuanku Jaafar Seremban from June 2016 until June 2017. Patients were classified into dengue positive and dengue negative based on dengue IgM and NS1 result. The diagnostic performance of MoV-SD and Mono % was analysed by receiver operating characteristic (ROC) curve analysis. The cut-off value of the MoV-SD and Mono % was determined and evaluated with the validation group. Chi-square test was used to assess the association between the parameters. Results: 88 (48.4%) from 182 samples were confirmed to have dengue infection. ROC curve analysis showed Mono % at cut off value of 10.5 % with area under the curve (AUC) of 0.869 with 84.1% sensitivity and 84% specificity (95% CI: 0.812-0.925) and MoV-SD cut off value at 22.2 (AUC 0.776, 80.7% sensitivity, 61.7% specificity, 95% CI: 0.709-0.843) are an excellent parameters in separating dengue positive and dengue-negative patients. A cut-off value of 10.5 of Mono % and 22.2 of MoV-SD were applied to the validation group showed 83.1%, 66.4% sensitivity and 84.9%, 77.3% specificity respectively. Conclusion: MoV-SD and Mono % parameters are a potential parameter for the screening of dengue infection in acute febrile illness patients with good specificity and sensitivity. Keywords:

Acute Kidney Injury in Non-Shock Dengue Hemorrhagic Fever

@#INTRODUCTION: Acute kidney injury (AKI) is one of the severe complications in dengue hemorrhagic fever, usually occurred in shock. We report an interesting case of AKI in a hemodynamically stable dengue hemorrhagic fever patient. CASE PRESENTATION: An 18-year-old male dengue fever patient referred to our institution in his day eight of illness due to three days of decreased urine output. He was hemodynamically stable with thrombocytopenia, increase in creatinine, positive for Anti dengue IgM, proteinuria, and hematuria. Ultrasound examination showed ascites. He was diagnosed with AKI stage III related to dengue hemorrhagic fever and underwent hemodialysis. A total of four series of hemodialysis and furosemide drip were performed during 12 days of admission and he was finally improved. CONCLUSION: Renal injury might occur in hemodynamically stable dengue hemorrhagic patients. It is a reversible condition; hence, appropriate treatment and close monitoring result in good outcomes

Scenario of dengue infection & its control in Pakistan: An up-date and way forward

Dengue fever is one of the major health problems in tropical and subtropical areas throughout the world. The causative agent of dengue fever is the dengue virus which is an enveloped single stranded RNA virus belongs to the family Flaviviridae and has five distinct serotypes (DENV-1, DENV-2, DENV-3, DENV-4 and DENV-5). Dengue virus is transmitted to human via bite of Aedes aegypti and Aedes albopictus mosquitoes. The clinical symptoms of dengue fever ranging from mild to severe form as dengue hemorrhagic fever and dengue shock syndrome. Pakistan is dengue endemic since 1994 but from 2006, Pakistan faced the worst condition regarding dengue in which thousands of people affected by the disease and hundreds of people lost their lives. DENV-2, DENV-3 and DENV-1 are the prevalent serotypes in Pakistan. Common diagnostic techniques are being used in Pakistan such as enzyme-linked immunosorbent assay, polymerase chain reaction and rapid diagnostic tests, while differential diagnosis, limitations of diagnostic methods and poor health care system are the real challenges in dengue diagnosis. Favorable climatic conditions, unplanned urbanization, travelling etc., are major factors responsible for dengue epidemics in Pakistan. This presentation provides update about dengue circumstances in Pakistan and also describes the way how to improve dengue situation in Pakistan.

Serodiagnosis of asymptomatic dengue infection

Dengue virus (DENV) is a mosquito-transmitted virus that is expanding across the world. The incidence of dengue infection, especially severe disease, has been increasing. DENV consist of 4 serotypes of single stranded RNA viruses (D1-D4) in the genus Flavivirus, family Flaviviridae. Majority of dengue infections are asymptomatic cases, which cause difficulty in disease control and are important in dengue surveillance. There is still no gold standard to diagnose asymptomatic dengue infection. Plaque reduction neutralization test (PRNT) has been developed for many purposes such as immunological study, clinical study, vaccine trial and is currently the most sensitive and specific method for serological surveillance. However, PRNT shows some degree of cross reaction among different dengue serotypes especially secondary dengue infection cases and to other flaviviruses. Moreover, various modification since the beginning make PRNT lack of inter-laboratory standardization which is an important issue. This paper discusses the important of asymptomatic dengue infection and its diagnostic method.

Asymptomatic dengue infection in adults of major cities of Pakistan

OBJECTIVE@#To determine the asymptomatic dengue infection in adults of Pakistani population.@*METHODS@#This study was conducted in five major cities (Islamabad, Karachi, Lahore, Multan, and Peshawar) of Pakistan. A total of 5 230 adults aged 18 years and above without a history of dengue fever at any point in their life were enrolled from participating laboratories. Those who were confirmed for dengue previously were excluded. Of the total, 62.6% (n = 3 276) were male with an average age of 34.6 years. Participants were briefed about the objectives of the study, and written consent was obtained to perform dengue IgG test using enzyme linked immunosorbent assay. The brief information related to age, gender and area was also taken on proforma.@*RESULTS@#Overall 32.3% (n = 1 691) was having asymptomatic dengue infection which was 67.5% (n = 756) in Karachi followed by 39.1% (n = 391) in Islamabad, 29.9% (n = 316) in Lahore and 21% (n = 228) in Peshawar and none from Multan. More males were affected with asymptomatic dengue infection than females. The asymptomatic dengue infection was significantly higher in different cities; however, there was no significant difference with respect to age groups.@*CONCLUSIONS@#The asymptomatic dengue infection is higher in cities i.e. Karachi, Islamabad and Lahore which are at risk of developing secondary dengue infections. There is a need of awareness among the public about secondary dengue infection.

Serodiagnosis of asymptomatic dengue infection

Dengue virus (DENV) is a mosquito-transmitted virus that is expanding across the world. The incidence of dengue infection, especially severe disease, has been increasing. DENV consist of 4 serotypes of single stranded RNA viruses (D1–D4) in the genus Flavivirus, family Flaviviridae. Majority of dengue infections are asymptomatic cases, which cause difficulty in disease control and are important in dengue surveillance. There is still no gold standard to diagnose asymptomatic dengue infection. Plaque reduction neutralization test (PRNT) has been developed for many purposes such as immunological study, clinical study, vaccine trial and is currently the most sensitive and specific method for serological surveillance. However, PRNT shows some degree of cross reaction among different dengue serotypes especially secondary dengue infection cases and to other flaviviruses. Moreover, various modification since the beginning make PRNT lack of inter-laboratory standardization which is an important issue. This paper discusses the important of asymptomatic dengue infection and its diagnostic method.

Asymptomatic dengue infection in adults of major cities of Pakistan

Objective To determine the asymptomatic dengue infection in adults of Pakistani population. Methods This study was conducted in five major cities (Islamabad, Karachi, Lahore, Multan, and Peshawar) of Pakistan. A total of 5 230 adults aged 18 years and above without a history of dengue fever at any point in their life were enrolled from participating laboratories. Those who were confirmed for dengue previously were excluded. Of the total, 62.6% (n = 3 276) were male with an average age of 34.6 years. Participants were briefed about the objectives of the study, and written consent was obtained to perform dengue IgG test using enzyme linked immunosorbent assay. The brief information related to age, gender and area was also taken on proforma. Results Overall 32.3% (n = 1 691) was having asymptomatic dengue infection which was 67.5% (n = 756) in Karachi followed by 39.1% (n = 391) in Islamabad, 29.9% (n = 316) in Lahore and 21% (n = 228) in Peshawar and none from Multan. More males were affected with asymptomatic dengue infection than females. The asymptomatic dengue infection was significantly higher in different cities; however, there was no significant difference with respect to age groups. Conclusions The asymptomatic dengue infection is higher in cities i.e. Karachi, Islamabad and Lahore which are at risk of developing secondary dengue infections. There is a need of awareness among the public about secondary dengue infection.

Metabolomics for characterization of gender differences in patients infected with dengue virus

OBJECTIVE@#To determine the metabolic response associate with dengue infection based on human gender metabolic differences by means of (1)H NMR-spectrometry.@*METHODS@#The mid-stream urine collected from both male and female patients diagnosed with dengue fever at Penang General Hospital and fourty-three healthy individuals were analyzed with (1)H NMR spectroscopy, followed by chemometric multivariate analysis. NMR signals which highlighted in the OPLS-DA S-plot were further selected and identified using Human Metabolome Database, Chenomx Profiler.@*RESULTS@#The results pointed out that NMR urine profiling was able to capture human gender metabolic differences that are important for the distinction of classes of individuals of similar physiological conditions; infected with dengue. Distinct differences between dengue infected patients versus healthy individuals and subtle differences in male versus female infected with dengue were found to be related to the metabolism of amino acid and tricarboxylic acid intermediates cycle.@*CONCLUSIONS@#The (1)H NMR metabolomic investigation combined with appropriate algorithms and pattern recognition procedures, gave an evidence for the existence of distinct metabolic differentiation of individuals, according to their gender, modulates with the infection risk.

Post dengue neurological complication

Dengue infection is highly endemic in many tropical countries including Malaysia. However, neurological complications arising from dengue infection is not common; Gullain–Barre syndrome (GBS) is one of these infrequent complications. In this paper, we have reported a case in which a 39-year-old woman presented with a neurological complication of dengue infection without typical symptoms and signs of dengue fever. She had a history of acute gastroenteritis (AGE) followed by an upper respiratory tract infection (URTI) weeks prior to her presentation rendering GBS secondary to the post viral URTI and AGE as the most likely diagnosis. Presence of thrombocytopenia was the only clue for dengue in this case.

Metabolomics for characterization of gender differences in patients infected with dengue virus

Objective: To determine the metabolic response associate with dengue infection based on human gender metabolic differences by means of 1H NMR-spectrometry. Methods: The mid-stream urine collected from both male and female patients diagnosed with dengue fever at Penang General Hospital and fourty-three healthy individuals were analyzed with 1H NMR spectroscopy, followed by chemometric multivariate analysis. NMR signals which highlighted in the OPLS-DA S-plot were further selected and identified using Human Metabolome Database, Chenomx Profiler. Results: The results pointed out that NMR urine profiling was able to capture human gender metabolic differences that are important for the distinction of classes of individuals of similar physiological conditions; infected with dengue. Distinct differences between dengue infected patients versus healthy individuals and subtle differences in male versus female infected with dengue were found to be related to the metabolism of amino acid and tricarboxylic acid intermediates cycle. Conclusions: The 1H NMR metabolomic investigation combined with appropriate algorithms and pattern recognition procedures, gave an evidence for the existence of distinct metabolic differentiation of individuals, according to their gender, modulates with the infection risk.

Predictors of dengue mortality in a tertiary care hospital at Kolkata: A cross sectional study.

Background: Dengue fever, the most common arbo viral illness transmitted worldwide. Dengue infection in adolescents and adults is also a potential hazard in endemic areas, especially South-east Asia. Aims & Objective: The present study was done to evaluate the magnitude of dengue death and its predictor factors in a tertiary care hospital of Kolkata. Material and Methods: This observational cross sectional study was conducted at a tertiary care centre of Kolkata over 1 year period with 77 patients with a diagnosis of dengue fever based on the serology positive for dengue IgM with fulfilling the inclusion and exclusion criteria. The data were collected on predesigned questionnaire which include gender, clinical findings, complications and laboratory test. Baseline laboratory tests obtained were complete blood count (CBC), partial thromboplastin time (PTT), serum glutamine pyruvate transaminase (SGPT), SGOT, bilirubin, urea, creatinine and IgM. SPSS 16.0 version was used for statistical analysis. Results: Dengue mortality rate was 28.57% in this study. Among 5 lab parameters chosen i.e. leukopenia, bilirubin > 6 mg/dl, thrombocytopenia, altered PT/APTT, enzyme > 4 fold rise, raised urea/cr. On multivariate logistic regression analysis hyperbilirubinemia (> 6 mg/dl) was statistically significant predictor for mortality (as p value < 0.05). Conclusion: The laboratory parameters could predict the dengue mortality, so proper emphasis should be given to address the situation.

Environmental influences on antibody-enhanced dengue disease outcomes

Because an enriched environment (EE) enhances T-cell activity and T-lymphocytes contribute to immunopathogenesis during heterologous dengue virus (DENV) infections, we hypothesised that an EE increases dengue severity. To compare single serotype (SS) and antibody-enhanced disease (AED) infections regimens, serial intraperitoneal were performed with DENV3 (genotype III) infected brain homogenate or anti-DENV2 hyperimmune serum followed 24 h later by DENV3 (genotype III) infected brain homogenate. Compared AED for which significant differences were detected between the EE and impoverished environmental (IE) groups (Kaplan-Meyer log-rank test, p = 0.0025), no significant differences were detected between the SS experimental groups (Kaplan-Meyer log-rank test, p = 0.089). Survival curves from EE and IE animals infected with the AED regimen were extended after corticoid injection and this effect was greater in the EE than in the IE group (Kaplan-Meyer log-rank test, p = 0.0162). Under the AED regimen the EE group showed more intense clinical signs than the IE group. Dyspnoea, tremor, hunched posture, ruffled fur, immobility, pre-terminal paralysis, shock and death were associated with dominant T-lymphocytic hyperplasia and presence of viral antigens in the liver and lungs. We propose that the increased expansion of these memory T-cells and serotype cross-reactive antibodies facilitates the infection of these cells by DENV and that these events correlate with disease severity in an EE.

Dengue HLA associations in jamaicans / Asociaciones del HLA con el dengue en los jamaicanos

BACKGROUND: Polymorphisms in the human leukocyte antigen (HLA) genes might predispose certain individuals to dengue fever (DF) and the severe forms of the disease: dengue haemorrhagic fever/ dengue shock syndrome (DHF/DSS). SUBJECTS AND METHOD: A DNA-based HLA typing method was used to determine the HLA class I and II alleles in 50 patients with dengue, including 45 cases of DF, 5 cases of DHF and 177 healthy individuals in Jamaica. RESULTS: HLA -A*24 and -DR β5*01/02 were significantly associated with dengue infection while possession of HLA -A*23, - CW*04, -DQ β1*02, -DQ β1*03 and DQ β1*06 were protective. No other significant associations were found after correction for the number of alleles tested at each HLA - locus. CONCLUSION: This is the first study to report a significant association with HLA -A*24 and DF although this allele is associated with DHF and DSS in Vietnamese patients. The other HLA associations observed in the Jamaican cohort also are different from those reported in other ethnic groups. Further studies which involve larger numbers of patients with DHF and explore functional aspects of HLA allelic associations with dengue in Jamaicans are necessary.

ANTECEDENTES: Los polimorfismos de los genes del antígeno leucocitario humano (HLA) podría predisponer a ciertos individuos a la fiebre de dengue (FD) y a las formas severas de esta enfermedad: la fiebre hemorrágica de dengue y el síndrome de choque por dengue (FHD/SCD). SUJETOS Y MÉTODO: Se usó un método de tipificación HLA basado en el ADN con el propósito de determinar los alelos HLA clase I y II en 50 pacientes con dengue, incluyendo 45 casos de FD, 5 casos de FHD y 177 individuos saludables en Jamaica. RESULTADOS: HLA -A*24 y -DR β5*01/02 estuvieron significativamente asociados con la infección de dengue en tanto que la posesión de HLA -A*23, -CW*04, -DQ β1*02, -DQ β1*03 y DQ β1*06 tenía carácter protector. No se halló ninguna otra asociación significativa tras la corrección en relación con el número de alelos probados en cada locus de HLA . CONCLUSIÓN: Este es el primer estudio que reporta una asociación significativa de HLA -A*24 y FD, aunque este alelo se halla asociado con FHD y SCD en pacientes vietnamitas. Las otras asociaciones observadas en la cohorte jamaicana son también diferentes de las que se reportan para otros grupos étnicos. Se requieren estudios ulteriores que comprendan grandes números de pacientes con FHD y exploren los aspectos funcionales de las asociaciones alélicas de HLA con el dengue en los jamaicanos.

Is West Nile virus a potential cause of central nervous system infection in Brazil? / Seria o vírus do Oeste do Nilo causa potencial de infecção no sistema nervoso central no Brasil?

Meningitis and encephalitis are complications of West Nile virus (WNV) infection. Although WNV is endemic in North America, the virus has recently been reported in Colombia and Argentina. Investigation of WNV in Brazil is important since this virus has never been studied previously in this country. OBJECTIVE: To investigate the presence of WNV infection in viral encephalitis/meningitis cases of unknown etiology in the city of Rio de Janeiro, Brazil. METHOD: Thirty-seven adults with viral meningitis/encephalitis had their serum and CSF tested for WNV antibodies using the ELISA method. RESULTS: Only one case was WNV-positive, but this case was also positive for dengue. The plaque reduction neutralization test distinguished infections, and was negative for WNV. CONCLUSION: WNV can be confused with dengue infection. Their symptoms and neurological picture are similar. We did not find WNV in any patients with encephalitis and meningitis in the city of Rio de Janeiro. Up to now, it has not been detected in Brazil.

Meningite e encefalite são complicações da infecção pelo vírus do Oeste do Nilo (VON). Embora o VON seja endêmico na América do Norte, recentemente o vírus foi descrito na Colômbia e Argentina. Sua pesquisa no Brasil é importante uma vez que o vírus nunca fora estudado antes em nosso país. OBJETIVO: Investigar a presença do VON em casos de meningite e encefalite viral de etiologia desconhecida, na cidade no Rio de Janeiro, Brasil. MéTODO: Trinta e sete adultos com quadro de meningite/encefalite tiveram seu LCR e soro testados para anticorpos anti-VON, pelo método ELISA. RESULTADOS: Apenas um caso obteve sorologia positiva para VON, mas a sorologia para dengue também fora positiva. O teste da neutralização por redução de placa foi utilizado para distinção entre as infecções, sendo negativo para VON. CONCLUSÃO: A infecção por VON pode ser confundida com a infecção pelo vírus da dengue, seus sintomas e quadro neurológico são similares. Nós não encontramos o VON em pacientes com meningite/ encefalite na cidade do Rio de Janeiro. Até o momento ele ainda não foi identificado no Brasil.

Correlation of disease spectrum among four Dengue serotypes: a five years hospital based study from India

The recognition of DF (DHF Dengue Hemorrhagic Fever) is very complicated due to occurrence of a wide spectrum of clinical signs and symptoms during acute phase of illness. Moreover, presence of four serotypes further complicates the prognosis. To investigate the predictors of disease severity and elucidate the prognostic markers among four dengue serotypes, this study was conducted on 320 inpatients having acute febrile illness clinically suspected as DI, over a period of five years. Dengue serotypes were confirmed by multiplex reverse transcriptase (RT)-PCR. Eighty patients were positive for DI with presence of Den-1, Den-2, Den-3, and Den-4 in 8, 35, 27 and 10 patients, respectively. The severe clinical manifestations, abdominal pain and hepatomegaly, were comparatively higher in Den-2 patients. Liver aminotransferases levels were also higher in Den-2 patients (app. 5 fold). This study clearly indicates the hyperendemicity of all dengue serotypes. Nucleotide sequencing of Envelope region revealed that the presently emerged Den-3 belongs to type III, having high homology with genotype responsible for number of outbreaks in 1980s. The re-emergence of this deadly type can be suspected to cause more outbreaks in future and is a matter of great concern.

Appropriate laboratory tests for the diagnosis of dengue infection at a general hospital in Southern Thailand

Background: Laboratory diagnosis of dengue infection is complicated by the variability of either virus, antigen or antibody appearance in blood circulation. Patients came to the hospital at different time intervals after the onset of fever. This resulted in problems in the selection of appropriate laboratory tests. Objective: To determine the appropriate laboratory assays for the diagnosis of dengue infection at a general hospital in Southern Thailand. Methods: Serum samples were obtained from 175 dengue-suspected patients attending Nakhon Si Thammarat Provincial Hospital, in Southern Thailand during the period January-September 2006. Dengue infected patients were classified as having clinical symptoms according to the WHO criteria for dengue infection combined with positive ELISA test results for IgM and/or IgG antibodies for dengue virus. All were assayed for dengue viral infection by real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR), Platelia Dengue NS1 Ag test (NS1-Ag), Dengue IgM Capture ELISA (ELISA-IgM), Dengue Indirect IgG ELISA (ELISA-IgG) and Dengue Duo IgM and IgG rapid strip test (RST). Results: One hundred of the 175 dengue suspected cases were diagnosed as having dengue viral infection. Thirty-eight cases (22%) were positive by NS1-Ag test, 36 (21%) by real-time RT-PCR, 41 (23%) by RST, 74 (42%) by ELISA-IgM and 88 (50%) by ELISA-IgG. Among the 100 positive cases, 40 cases (40%) were determined as primary infection and 60 cases (60%) as secondary infection on the basis of the variability of specific IgG and IgM levels in patient serum. The NS1-Ag test kit, real-time RT-PCR and RST detected more positive cases in primary infected patients compared to secondary infected patients (p \< 0.0001). With ELISA-IgG when combined with NS1-Ag, RT-PCR or ELISA-IgM, 88, 89 and 96% of the cases could be detected. Three combinations of ELISA-IgG, ELISA-IgM with NS1-Ag or RT-PCR resulted in 99 and 100 % positive cases. Conclusion: A combination of ELISA-IgG, ELISA-IgM with NS1 Ag test was appropriate for laboratory diagnosis of dengue infection at the hospital where equipment for running ELISA tests was available.

Risk factors influencing severity in pediatric dengue infection

Background: Dengue disease encompasses a wide spectrum of clinical presentations. While the severity of dengue disease can vary from patient to patient, it is, however, still unclear as to what factors determine dengue disease severity.Objective: To analyze the potential risk factors such as: sex, age, nutritional status, dengue serotypes, D-dimer positivity, and serologic responses, and study their correlation with the severity of dengue virus infection.Methods: Dengue patients at King Chulalongkorn Memorial Hospital were enrolled for the study. Dengue serotype was determined by PCR and primary or secondary infection was determined based on serological criteria. D-dimer levels were also tested using a rapid semiquantitation system. Clinical data such as age, body weight, sex, and nutritional status were also collected.Results: Forty-six patients were confirmed for dengue fever (DF), and 52 patients were confirmed for Dengue hemorrhagic fever (DHF). 77.5% of patients had secondary dengue infection, 11.3% had primary infection, and 11.2% were of inconclusive status. Gender and age of patients did not correlate with dengue disease severity (p \> 0.05). It was inconclusive as to whether nutritional status was a risk factor. Positivity of the D-dimer test was statistically significant for DHF (p=0.001). Early increasing D-dimer in the febrile stage could predict severity of dengue infection during the initial stage of the disease (positive predictive value=68.4 %).Conclusion: D-dimer is significantly correlated with dengue severity and it may be one of the prognostic factors for dengue infection in children.