Dengue IgG Antibodies Research Articles

Seroprevalence of Arboviruses in Travelers in Morocco: Focus on Dengue and Zika

Dengue and Zika viruses belong to the arbovirus family and are emerging infectious diseases transmitted by Aedes mosquitoes, prevalent in tropical and subtropical regions. Their proliferation is facilitated by factors such as adaptability, climate change, and globalization. Despite surveillance efforts by the World Health Organization (WHO), global monitoring remains limited. This study aimed to ascertain the seroprevalence of these diseases among travelers returning from endemic regions. A prospective, cross-sectional study was conducted on 2023 targeted travelers in the Democratic Republic of Congo and the Central African Republic. Participants were selected based on specific criteria over a six-month period. Blood samples were assessed in our laboratory using the VirClia® automated chemiluminescence immunoassay to detect Dengue and Zika IgG and IgM antibodies. The analysis involved interpretation of the results using a specific formula. The study included a young, asymptomatic cohort, averaging 30.8 years of age. Travelers were categorized according to age, sex, and country of residence. Dengue virus seroprevalence was 18.6%, predominantly IgG. The prevalence of ZIKV infection was 12.9%. The seroprevalence of these arboviruses varies according to sociodemographic factors. Epidemiological studies play a crucial role in assessing the prevalence of vector-borne diseases and informing public health strategies to mitigate their global impact.

A-261 Outcome of a survey on dengue lateral flow immunoassay test kit reading and interpretation by medical laboratory staff in a hospital laboratory

Abstract Background Lateral flow immunoassay (LFIA) tests, first introduced in 1959, are now the mainstay of clinical laboratories. Khoo Teck Puat Hospital (KTPH) is a 795-bed acute care general hospital located in the north of Singapore. The Department of Laboratory Medicine has been using dengue LFIA test kits for the detection of dengue NS1 antigen, IgM antibodies and IgG antibodies. While kits are cost-effective, user-friendly and provide rapid results, there is subjectivity in reading and interpretation of results. Methods We conducted a survey to assess test reading and interpretation by medical laboratory staff. Six serum and plasma specimens were analysed using Bioline™ Dengue IgG/IgM WB test device. Test kits at the end-point of sample incubation were photographed in both well-lit and dim conditions. A survey questionnaire was prepared using an online form builder tool using the photographs. Staff were invited to participate in the survey. They were allowed to report the result as ‘Positive’, ‘Negative’ or ‘Equivocal’. Results A total of sixteen responses were received. Results were 100% concordant for all 6 specimens in both well-lit and dim conditions. For one case, under a well-lit condition, 15 staff reported the result as ‘Positive’ while one staff reported ‘Equivocal’. Most of the reported results for samples with no consensus is split between ‘Positive’ and ‘Equivocal’. Conclusions Dengue viruses of all 4 known serotypes are endemic in Singapore. Positive results are tracked on a national level to identify areas of high dengue infection for intensive environmental and vector control measures. Hence, accurate reporting and identification of patients with dengue infection is important. Our survey shows that lighting conditions do not affect the interpretation of LFIA results. Reading and interpretation of dengue LFIA test kits however, remain dependent on user interpretation and newer test kits with optical readers may be useful in mitigating this.

LYME AND DENGUE FEVER: FROM BANGLADESH TO ITALY

Abstract Background Dengue fever (Flavivirus) and Lyme disease (Borrelia burgdorferi) are rare tropical infectious diseases transmitted by hematophagous vectors (Aedes mosquitoes and ticks, respectively), and they are extremely uncommon in Italy. In European countries, both represent a public health concern as they manifest as imported diseases. Case Report A 54–year–old man from Bangladesh was admitted with symptoms of fever, dyspnea, and pericarditic chest pain. Laboratory and imaging examinations revealed severe acute respiratory failure secondary to left lower lobe pneumonia and pleuropericardial effusion. Broad–spectrum antibiotic therapy and anti–inflammatory treatment were initiated, suspecting para–pneumonic pleuropericarditis. During hospitalization, there was a gradual improvement with a reduction in inflammatory indices and resolution of lung consolidation. The patient was discharged after 14 days with anti–inflammatory therapy (ibuprofen and colchicine). Approximately 7 days later, the patient returned to the emergency department complaining of a recurrence of symptoms and fatigue. The EKG showed phases of 2:1 AV block, EAS and EPS, complete de novo left bundle branch block (LBBB), alternating with an escape atrial rhythm, not evident in previous EKG. During hospitalization, complete AV block emerged with prolonged asystolic phases, requiring urgent placement of a temporary pacemaker. Concurrently, blood tests revealed anemia and increased levels of inflammatory markers, troponin, creatinine, transaminases, cholestatic indices, LDH, and lipase, indicative of multiple organ failure (MOF). Acute pathologies or active bleeding were ruled out by total body CT with contrast. Blood cultures and serological tests were performed to exclude infections by Trichinella, Mycoplasma, Borrelia, Dengue, and other rare infectious diseases. Due to progressive deterioration, the patient was transferred to a tertiary care hospital. In the following days, laboratory results showed positive IgG and IgM for Dengue (without serological evidence of viral RNA) and positive IgG and IgM antibodies for Borrelia burgdorferi. Conclusion In Italy, the incidence of these diseases is low, and their coexistence in the same host is even rarer (if not anecdotal). However, coinfection cannot be excluded in patients from areas where these diseases are endemic, such as Bangladesh.

Exploring the Therapeutic Potential of Glycyrrhizic Acid in Liver Implication in Dengue Infection: A Case Report

Dengue is one of the most common infectious diseases affecting humans. The virus is transmitted between humans by the Aedes mosquito. It occurs hyperendemically in tropical and subtropical climates worldwide. Dengue infection can affect numerous organs, with the liver being the most frequently affected organ. The clinical spectrum of liver disorders ranges from mild elevation of transaminase enzymes to severe conditions such as acute liver failure. Several mechanisms have been proposed to describe hepatic dysfunction observed in dengue fever and dengue hemorrhagic fever, such as immunological injury, hypoxic injury, and direct viral damage due to reduced hepatic perfusion during shock. Glycyrrhizic acid, extracted in the form of glycyrrhizin from the root of the licorice plant Glycyrrhiza glabra, is referred to as Stronger Neo-Minophagen-C (SNMC®). It has shown effectiveness in reducing serum aminotransferase and bilirubin levels, attenuating hepatocyte apoptosis, and producing endogenous interferon. The following is a case report of a 23-year-old woman with dengue fever and elevated liver enzyme level. The patient’s vital signs were stable. A physical examination revealed no abnormalities. A complete blood count test showed thrombocytopenia without an elevation of the hematocrit. AST level was 901 U/L after admission. Causes of other hepatitis infections, such as hepatitis A, B, and C, were excluded. The dengue IgM and IgG antibody levels were reactive. After several days of hospitalization, the patient experienced clinical improvement after supportive therapy and the administration of glicyrrhizic acid or SNMC®.

First report of dengue virus among febrile malaria positive and negative patients in Nyala city, Western Sudan

Background: The mosquito borne dengue fever and malaria -; are major public health concerns in tropical settings. They are highly prevalent and considered one of the main etiology of febrile illnesses in Sudan. Aim: This study aimed to determine seroprevalence of dengue virus among febrile malaria positive and negative patients in Nyala city, Western Sudan by using Enzyme linked immuno sorbent assay (ELISA) to detect dengue virus IgM and IgG antibodies. It also aimed to study possible risk factors that may be associated with dengue virus and malaria infections. Methods: This cross sectional study, which was undertaken in different Hospitals in Nyala city, South Darfur state Sudan during June to December 2021. A total of 93 blood samples from febrile patients were collected in EDTA containers. Plasma was obtained by centrifugation and tested by ELISA (EUROIMMUN, Germany) according to manufactures instructions for dengue virus IgG and IgM antibodies. Malaria parasites were detected using microscopy of stained blood smears. Generated data was analyzed using the statistical package (SPSS) version 21. Results: Forty six (49.5%) out of 93 febrile patients were found infected with malaria parasites using blood smear microscopy. Among these malaria infected patients, the prevalence of dengue anti-virus IgG (49 .5%) was higher than that of IgM (16.1%) but was statistically insignificant (p>0.05). In the present study dengue infection was higher in males than in females but was statistically insignificant (P> 0.05) and the Age group 21-40 years was the most affected with dengue virus infection. Conclusion: The present study showed higher prevalance rate of dengue IgG among the participants of study more than IgM but was statistically insignificant There was no association between age and gender with seroplevance of dengue virus among febrile patients with and without malaria. The frequent existence of infections of DENV requires improved surveillance and control measures to combat this disease in Nyala, Sudan.

Dengue COVID-19 overlap: antigenic mimicry or concurrent two viral diseases

Background: Dengue-COVID-19 overlap is mixture of both diseases sharing few similarities in pulmonary and extrapulmonary involvement. Due to high prevalence of both diseases later being pandemic disease, and overlapping laboratory and clinical parameters we have conducted a study to observe dengue-COVID-19 overlap in Indian settings in tertiary care hospitals.
 Methods: Prospective, observational study, included 600 COVID-19 cases with dengue NS1 or Dengue IgM positive, with lung involvement documented and categorized on HRCT thorax at entry point. All cases were subjected to dengue IgG antibody titers and dengue IgM/IgG antibody titer analysis after 12 weeks of discharge form hospital.
 Results: Dengue- COVID-19 overlap was documented in 16.33% (98/600) cases. CT severity has documented significant correlation with Dengue-COVID-19 overlap cases. [p<0.00001] Hematological evaluation, white blood cell count & platelet count were having significant association with Dengue-COVID-19 overlap [p<0.0076] & [p<0.00001] respectively. Clinical parameters as hypoxia have significant association with dengue- COVID-19 overlap. [p<0.00001] Inflammatory markers as IL-6, CRP and LDH has significant association in dengue-COVID-19overlap [p<0.00001] respectively. In study of 98 cases of ‘Dengue-COVID-19’, post covid lung fibrosis [p<0.004] and serological assessment in dengue IgM/IgG and covid antibody titers has significant association [p<0.00001]
 Conclusion: Dengue-COVID-19 overlap is clinical syndrome with overlapping clinical and laboratory workup of both the illnesses. High index of suspicion is must in all covid cases in tropical settings where dengue is endemic; and all cases with leucopenia and thrombocytopenia with fever should be screened for dengue serology. False positive dengue serology or dengue antigen crossreactivity is known to occur in underlying COVID-19 illness, and have impact on clinical outcome as it will result in delay in covid appropriate treatment initiation and many cases require intensive care unit treatment due to progressed covid pneumonia.
 Bangladesh Journal of Medical Science Vol. 23 No. 01 January’24 Page : 189-199

First serological prevalence of dengue virus IgG antibody among pregnant women in Port Harcourt, Nigeria

Dengue is a viral disease transmitted by Aedes mosquitoes and is considered a public health problem worldwide. Pregnant women and infants are at risk of developing severe dengue, which has been linked to poor outcomes. This study sought to determine the prevalence of Dengue Virus IgG antibodies among pregnant women attending antenatal care at the University of Port Harcourt Teaching Hospital, Rivers State, Nigeria. In this cross-sectional study, a total of 94 pregnant women were enlisted, and after gaining consent, approximately 5 ml of whole blood was taken. Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect the presence of IgG antibodies to the dengue fever virus. IgG antibodies prevalence to the dengue fever virus was found to be 2.1%. Women who were within 16 to 20 years (6.7%), single (2.6%), employed (3.8%), had primary education (5.3%) and resided in urban areas (4.8%) all had higher incidence rates. Although this study reported a low prevalence of dengue virus among pregnant women, intensive enlightenment on the preventive measures which include the use of insect repellant and wearing of long-sleeved shirts, among others, should be sustained.

Seroprevalence of IgG Antibodies Directed against Dengue, Chikungunya and West Nile Viruses and Associated Risk Factors in Madagascar, 2011 to 2013.

Arboviruses have been shown to circulate in Madagascar, including West Nile, dengue, and chikungunya viruses, though the extent of their circulation remains poorly documented. We estimated the seroprevalence of these three arboviruses in Madagascar and determined risk factors associated with seropositivity. Serum samples obtained from 1680 individuals surrounding the Sentinel Health Centers network in all regions of the country were analyzed using ELISA and hemagglutination inhibition assays for dengue, chikungunya, and West Nile viruses IgG antibodies, and multivariate logistic regression models were run. Overall, 6.5% [IC 95% 3.2-9.9] were seropositive for dengue virus, predominantly of Dengue serotype 1, 13.7% [IC 95% 6.5-20.9] for chikungunya virus, and 12.7% [IC 95% 9.0-16.5] for West Nile virus. There was no association with age, showing that dengue and chikungunya viruses were likely recently introduced. Eastern and Northern parts were more affected by dengue and chikungunya viruses, while West Nile virus seemed to circulate in all parts of the country. Dengue and chikungunya seropositivity were notably associated with high levels of vegetation, as well as frequent work in the forest, and West Nile seropositivity with the presence of cultivated areas, as well as standard of living. This analysis gives a new insight into arboviruses circulation and transmission patterns in Madagascar.

Dengue Burden and Circulation of Dengue-2 Serotype Among Children Along With Clinical Profiling in Uttarakhand, India: A Cross-Sectional Study From 2018 to 2020.

The multiple serotypes of the dengue virus (DENV) are always a major public concern for dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). This study aimed to analyse the demographic characteristics and circulating serotypes of dengue among the paediatric age group. One hundred forty-one clinically suspected children were enrolled in the study from 2018 to 2020 in a tertiary care hospital in Uttarakhand, India. Central tendency, frequency, and One-Way ANOVA were measured for continuous and categorical data. The Shapiro-Wilks test was used to calculate the normality assumption. Dengue NS1 Ag, IgM, and IgG antibodies ELISA were performed, and NS1-positive samples were further tested for molecular studies. From one hundred forty-one suspected cases, 100 (70.92%) came positive for dengue NS1 antigen, 18 (12.76%), and three (2.12%) came positive for IgM and IgG antibodies respectively. Rest 20 (14.18%) samples came negative for dengue. Fever with chills (97.5%), headache (89%), and arthralgia (82%) were the most common clinical features. Molecular studies showed the dengue serotype-2 (DEN-2) was found in most cases, followed by the dengue-3 serotype (DEN-3). This is the preliminary study as the authors' best knowledge which demonstrate the burden of dengue in children with prevalent serotypes for consecutive three yearsin Uttarakhand. This study identifies that the serotype-2 (DEN-2) of the dengue virus was the primary cause of infection in children at the tertiary care hospital in northern India. These results will help further to understand the nature of the disease so that improved patient care management will imply. Further molecular studies on large sample sizes during the endemic would be helpful to gain knowledge of the actual load of the disease and the genetic characteristics of the virus.

Serological Evidence of Zika virus Circulation with Dengue and Chikungunya Infections in Sri Lanka from 2017.

Arbovirus diseases remain a public health threat in Sri Lanka. Dengue is endemic and two outbreaks of chikungunya infections have been reported. There is limited data on Zika virus (ZIKV) infections in Sri Lanka, and this could be due to a lack of comprehensive ZIKV surveillance. Our aim was to determine the presence of antibodies to dengue, chikungunya, and Zika infections in adults from a suburban population in Sri Lanka. A total of 149 healthy adult volunteers over 18 years of age (mean age: 43±14 years, males - 43%), with no prior diagnosed arboviral infections and no history of overseas travel, participated in the study. ELISA and neutralization assays were carried out to detect past dengue, chikungunya, or Zika infections. A total of 94.6% (141/149) of the participants demonstrated dengue IgG antibodies, 37.5% (56/149) were positive for chikungunya IgG, and 5.3% (8/149) were positive for anti-ZIKV IgG antibodies. Neutralization assays confirmed ZIKV-specific antibodies in 6.7% (10/149), when 40/149 of the participating population were tested. This clearly demonstrated past ZIKV infections in this population. In addition, this study indicates that >90% of individuals had asymptomatic dengue but no serious symptoms. These results provide a cross-sectional view on the DENV, ZIKV, and CHIKV epidemic status and demonstrate a need for the implementation of enhanced surveillance and more effective measures against the spread of these arbovirus diseases.

109. Seroprevalence of Protective Antibodies against Varicella, Hepatitis-A and Dengue among Indian Children, Adolescents and Adults

Abstract Background Varicella, Hepatitis-A and Dengue cause significant disease burden in our country. Estimation of age-wise seroprevalence of antibodies against these diseases not only help us in understanding age-specific incidence rates and susceptibility, but also help policy makers in deciding need and timing of vaccination. None of these vaccines are part of current national immunization program in India, yet. Methods In this observational cross-sectional study, apparently healthy children (9-12 years), adolescents (15-18 years) and adults (25-30 years) attending OPD of a tertiary care hospital in Northern India over two-year period (July 17- June 19) were enrolled after taking informed written consent, and their 3-ml venous blood sample was collected. Ethical clearance was obtained from Institute Ethics committee, before enrolling subjects. Serum was tested for IgG antibodies using specific commercial ELISA kits. Those who received received Hepatitis-A or Varicella vaccination in past were excluded from enrollment. Results Out of total 240 subjects (M:F=117:123) enrolled, 75 were children, 75 adolescents and 90 adults in specified age groups. Mean age in these three groups were 11.04, 16.52 and 26.53 years respectively. In our study, antibodies (IgG) against Varicella were >12 U/ml (seroprotective) in 36% (27/75), 74.6% (56/75), 64.5% (58/90) in children, adolescent and adults in specified age groups, respectively. Similarly, the antibodies (IgG) against Hepatitis-A were >10 U/ml (seroprotective) in above three groups were 68% (51/75), 85.3% (64/75), 95.5% (86/90). For dengue IgG antibodies also, seropositivity rates in above three groups were 37.3% (28/75), 62.7% (47/75), 53.3% (48/90). Conclusion Large proportion of children, adolescents and adults remain susceptible to Varicella and Hepatitis-A infection in India. Early childhood vaccination with Varicella and Hepatitis-A vaccines should be a part of National Immunization Programme in India, as a part of preventive strategy. Our study also showed a large proportion of children, adolescents and adults remain seronegative for Dengue antibodies in various age groups. Therefore, if currently available dengue vaccine (Dengvaxia) has to be used in our population, it can only be used after individual screening. Disclosures All Authors: No reported disclosures.

Korelasi Nilai Hematokrit dan Jumlah Trombosit dengan Antibodi IgG dan IgM Dengue

Dengue virus infection can affect blood cells, one of which is the number of platelets so that it decreases, due to the formation of viral antibody complexes that stimulate platelet aggregation. DHF is characterized by plasma leakage with an increase in hematocrit >20%. Diagnosis of dengue virus infection is supported by examination of IgG and IgM antibodies, platelet count, and hematocrit. The purpose of this study was to determine the correlation between hematocrit and platelet counts with IgG and IgM antibodies to DHF. Research method: cross-sectional. Laboratory data were processed using the SPSS Chi-Square test software. The results of the statistical test of the correlation between IgG/IgM antibody results with platelet count p = 0.375 and IgG/IgM antibody results on hematocrit p = 0.487 so that it has a significance value of > 0.05. Conclusion: there is no correlation between hematocrit value and platelet count with dengue IgG and IgM antibodies.

‘Dengue-COVID-19 overlap’: Is it an ‘antigenic mimicry’ or coexistent two different viral genotypic diseases? Prospective, observational study in tertiary care setting in India

Introduction: Dengue-COVID-19 overlap is mixture of both diseases sharing few similarities in pulmonary and extra pulmonary involvement. Methods: Prospective, observational study, included 300 COVID-19 cases with dengue NS1 or dengue IgM positive, with lung involvement documented and categorized on HRCT thorax at entry point. All cases were subjected to dengue IgG antibody titers and dengue IgM/IgG antibody titer analysis after 12 weeks of discharge form hospital. Results: Hematological evaluation, white blood cell count & platelet count were having significant association with dengue-COVID-19 overlap (p<0.0076) & (p<0.00001), respectively. Clinical parameters as hypoxia have significant association with dengue-COVID-19 overlap (p<0.00001). Inflammatory markers as IL-6, CRP, and LDH has significant association in dengue-COVID-19 overlap (p<0.00001), respectively. Dengue-COVID-19 overlap was documented in 16.33% (49/300) cases. CT severity has documented significant correlation with dengue-COVID-19 overlap cases (p<0.00001). In study of 49 cases of ‘dengue-COVID-19’, post-COVID-19 lung fibrosis (p<0.004), and serological assessment in dengue IgM/IgG and COVID-19 antibody titers has significant association (p<0.00001). Conclusion: ‘Dengue-COVID-19’ is disease of concern in ongoing pandemic in critical care setting, and timely workup is crucial step in preventing delay in diagnosis and final adverse outcomes.

Clinical Study of Thrombocytopenia in Dengue Fever

INTORODUCTION: Dengue is a mosquito-borne viral disease by Flaviviridae family causing wide spectrum of disease ranging from subclinical disease, severe flu-like symptoms to severe dengue associated with severe bleeding, organ impairment and/or plasma leakage with higher risk of death when not managed appropriately. WHO classifies as DF/ DHF/DSS earlier, at present as Dengue (with or without warning signs) and Severe Dengue. The virus may be detected by NS1antigen and by ELISA IgM IgG antibodies. Thrombocytopenia is one of the laboratory parameter in grading severity, a study is planned during an epidemic in south Karnataka region which would have a substantial impact on management by reducing morbidity and mortality associated with dengue. AIMS AND OBJECTIVES: To correlate warning signs, laboratory parameters in different age groups, sex, with severity of thrombocytopenia with management. MATERIAL AND METHODS: Prospective observational study conducted at south Karnataka for patients more than 15 years with Dengue NS1Antigen positive or IgM/IgG positive and Platelet count less than 1, 50,000 per dl. Detailed clinical history and detailed physical examination was recorded in a prescribed preform and subjected to Dengue NS1Antigen, IgM and IgG antibodies, Complete blood count, Random Blood Sugar, Urine analysis, Liver Function tests, Renal Function tests, Abdominal sonography, ECG and managed conservatively. Data was entered in Microsoft Office Excel Sheet 2010 and analyzed. RESULTS: There are 124 thrombocytopenia, out of which 76 severe,34 moderate and 14 mild thrombocytopenia ,74(60%) are NS1 positive and 57(46%) are IgM positive,79 males (64%) and 45 females (36%), 49%are in 15-30 age (12% in 15-20, 37% in 21-30)and 20% in 31-40age, commonest clinical presentations along with fever are Headache 70%, myalgia 68%, nausea and vomiting 41%, arthralgia 27%, warning signs are abdominal pain 18%, bleeding manifestations 6%, restlessness 8%, altered sensorium 4%, bradycardia 26%, hypotension 17%, hepatomegaly 11%, abnormal laboratory parameters are leucopenia in 43%, abnormal renal function tests in 20%, elevated liver enzymes in 35% cases88%.There are 88% Dengue with warning signs,24% Severe Dengue with 17% circulatory collapse, 14% renal, 8% hepatic and 4% nervous involvement. Platelet transfusion done only in 27%. CONCLUSION: Moderate to severe thrombocytopenia in young adults with NS1 / IgM positive is the commonest warning sign followed by abdominal pain, bleeding manifestations, restlessness, altered sensorium, leucopenia, bradycardia, hypotension, polyserositis, abdominal tenderness, hepatomegaly, elevated liver enzymes, hyperbilirubinemia, abnormal renal function tests . Majority require supportive management and maynot require platelet transfusion. Early recognition of warning signs and meticulous management can reduce the morbidity and mortality of dengue.

Dengue Infection - Seroprevalence and Seasonal Variation among patients attending a Tertiary Care Hospital at Visakhapatnam, Andhra Pradesh, India

Introduction: Dengue infections have become a considerable threat to public health systems in developing countries. This study determines seroprevalence of dengue virus, seropositivity of Dengue NS1 antigen, IgM and IgG antibodies, Seasonal variation of dengue infection, and demographic profile of dengue-positive patients. Methods: A retrospective study was conducted at the Microbiology Department of Gayatri Vidya Parishad Institute of Health Care and Medical Technology, Visakhapatnam, India, from January 2018 to December 2019. A total of 5554 samples were collected from patients who were suspected of suffering from Dengue fever in the Medicine and Paediatrics wards. The patients were checked using Dengue Duo rapid test method from a commercial supply for combined Dengue NS1 antigen, IgM, and IgG antibody detection. Results: A total of 5554 serum samples were analyzed, among which 1045 were Dengue positive. The seroprevalence of dengue was 21.13% (95% confidence intervals (CI) 19.8– 22.6%) in 2018 and 15.40% (95% CI 13.9– 16.9%) in 2019. NS1 was positive in 835 (79.9%), IgM was positive in 26 (2.48%), IgG was positive in 116 (11.10%), and 68 were positive with both antigens and both antibodies. An outbreak occurred from July to October, indicating increased vector transmission in the monsoon and post-monsoon periods. Conclusion: The present study confirms that Dengue is mainly a disease of the rainy season, and effective implementation of vector control measures through efforts toward vector breeding source reduction and using personal prophylactic measures against mosquito bites will help in reducing the dengue prevalence in the community.

Dengue virus E protein-based luciferase immunosorbent assay for detecting dengue virus IgG antibody

To establish a luciferase immunosorbent assay (DENV-LISA) based on dengue virus (DENV) E protein, a specific antigen of DENV, for detection of DENV IgG antibody. The fused expression plasmids of DENV1-E1 and DENV2-E2 with luciferase were constructed. The plasmids were transfected into 293T cells, and the fusion protein containing the specific antigen and luciferase was obtained for establishing DENV-LISA. The specificity and sensitivity of DENV-LISA were assessed and compared with those of commercial DENV IgG antibody detection kit (ELISA). The established DENV-LISA had a positive detection rate of 32.4% and a specificity of 96.6%, showing a similar positive detection rate with the commercial ELISA kit (35.3%; P>0.05). DENV-LISA was capable of detecting positive samples with a 1: 6400 dilution with a high sensitivity. The test values of DENV-LISA did not differ significantly between plates or within plates in the same batch (P> 0.05), suggesting a good reproducibility of the test. The luciferase immunosorbent assay based on DENV E protein has high specificity and sensitivity for detecting DENV IgG antibody, and can be used for early screening, surveillance and epidemiological investigation of DENV infection.

Seroprevalence of three emerging arboviral infections in Kuwaiti nationals

Diseases caused by dengue, sandfly fever and hanta viruses pose a major health risk in many countries. We determined the threat of these arboviral infections through a serologic using enzyme linked immunosorbent assay (ELISA) based tests. Hantavirus-specific antibodies were also detected using immunofluorescence. Of 499 samples tested for dengue virus IgG antibodies l4% were as positive for dengue positive by all the ELISA tests. Among the 42 showing strong IgG reactivity, only 1 was positive for dengue virus IgM antibodies. All samples tested for IgG antibodies to sandfly fever virus were negative. Hantavirus antibodies were detected in 11% of the 46 samples from high-risk individuals. The low prevalences suggest that at present these infections are not a serious problem in Kuwait.

Evaluation of Concurrent Malaria and Dengue Infections among Febrile Patients- A Cross-sectional Study

Introduction: There are several tropical mosquito borne infections, such as Malaria and Dengue, these are the two major and common arthropod borne infections that cause high morbidity and mortality in many patients and are major public health concern worldwide. Concurrent malaria and dengue infection is an important condition that is infrequently reported. Aim: To find out the prevalence rate of co-infection for both dengue and malaria and also to associate the severity of such co-infections with symptoms and haematological parameters. Materials and Methods: In observational cross-sectional study, samples were collected from 604 febrile patients clinically suspected for malaria and dengue attending the Medicine Out Patient Department (OPD) of Dhiraj Hospital, Gujarat, India. The samples were diagnosed for malaria by using rapid malaria antigen test kit and peripheral blood smear microscopy for the identification of Plasmodium spp. The dengue NS-1 antigen, (Immunoglobulin) IgM and IgG antibodies rapid kit were use to rule out dengue infection. The statistical analysis done by software EPI info. Results: In the present study, out of 604, 58 patients (9.6%) were positive for malaria and 80 patients (13.24%) were positive for dengue, while 21 patients (3.47%) were having concomitant infection with both dengue and malaria. The most affected age group was 31-60 years, 45.53%. The study revealed male preponderance (61.59%), hepatomegaly and jaundice were seen in 52.38% patients, haemorrhagic manifestations in 23.80%, kidney failure in 4.76% (1), and thrombocytopenia (platelet count &lt;150,000/cubic millimeter (cmm)) were noted in 95.23% patients. Conclusion: It is mandatory to test any febrile patient for both malaria and dengue so that the diagnosis of the patient is not held back by missing any one. The clinicians who treat febrile patients in or from endemic areas must thoroughly examine and diagnose for both malaria and dengue, still one or the other is positive. Vector control, health education and good hygiene are community based preventive measures that are needed to control both the diseases.

Seroepidemiology of dengue viral infection at a tertiary care hospital, Bommakal, Karimnagar, India

Introduction: Dengue viral fever has become a disease of major concern. India in last decade has faced many outbreaks and now declared as an endemic zone. Therefore, the present study was designed: Aim: To know the prevalence of dengue viral infection in the north east region of Telangana state Bommakal, Karimnagar, the prevalence of acute primary and recent secondary dengue viral infection and the influence of various demographic factors. Materials and Methods: A retrospective observational study was designed during the period Jan.2015 –Dec. 2016 from 6706 suspects of dengue fever. Dengue NS1 antigen, IgM and IgG antibodies were detected using rapid immunochromatographic test from J. Mitra Co. Results: About 2686 (40.05%) gave a positive serological test for dengue viral infection. Acute primary dengue infection was diagnosed in 2375 (88.42%) of the suspects and recent secondary in 37 (1.37%) presumptively. Male predominance of 68.92% was noticed in suspects and as well seropositives as 64.18%. The most affected age group was 16-30 years followed by 31-45years as 58.32% and 25.39%. Further it is noticed that infection was prevalent throughout the year with seasonal spurts in monsoon and post monsoon. Highest percentage of suspects and cases were observed during the months Sep – Nov 72.93%% and 81.57%. Conclusion: Dengue primary infection is very high in this particular region of Telangana state and seasonal upsurge is seen during monsoon and post period of the year. High male preponderance is seen with maximum affected in the productive age group. Dengue ICT test are most suitable for point of care testing for early case detection and management but couldn’t provide specific clue on disease epidemiology; which is essential for monitoring, surveillance and implementing effective vector control measures. Keywords: Dengue, NS1 antigen, IgM and IgG antibodies, Acute primary and recent secondary infection.

Epidemiological and virus molecular characterization of dengue fever outbreak in Hunan province, 2018

Objective: To analyze the epidemiological and etiological characteristics of a dengue fever outbreak in Hunan province in 2018. Methods: Real-time PCR assay was performed for the laboratory diagnosis of 8 suspected dengue fever cases. Etiological surveillance was performed in 186 suspected dengue fever cases and fever cases who had close contacts with dengue fever patients. C6/36 cells was used for the virus isolation from acute phase serum. By sequencing the full length of E genes of 15 dengue virus strains, phylogenetic analysis was performed based on the sequences obtained, including reference sequences from the NCBI GenBank database, the serotypes and gene subtypes of the virus were analyzed to trace the possible source of transmission. An emergency monitoring of vector density and a retrospective survey of sero-epidemiology in healthy population were conducted in the epidemic area. Results: In the serum samples of 8 suspected patients, 6 were dengue virus RNA positive, and 4 were NS1 antigen positive. In 186 suspected patients, 96 were dengue virus nucleic acid, NS1 antigen or antibody positive in etiological test. A total of 64 dengue virus strains were isolated. The phylogenetic analysis showed that all the dengue virus strains belonged to type 2, which might be from Guangdong or Zhejiang provinces. The Bretub index was up to 65, indicating an extremely high risk of transmission. The positive rate of the dengue virus IgG antibody was 0.53%(2/377) in retrospective survey of 377 healthy people. Conclusion: The field epidemiologic and the molecular genetics analyses showed the outbreak of dengue fever in Hunan in 2018 was caused by imported cases and dengue virus 2.