Dengue NS1 Research Articles

Investigating the Clinico-Demographic Characteristics of Dengue Fever and Its Seroprevalence at a Tertiary Care Hospital in Northern India.

Background and objective Dengue virus (DENV) is a major global health threat, causing over 50,000 deaths annually. The state of Uttar Pradesh (UP) in India faces significant challenges due to the increasing number of dengue cases detected. This study aimed to assess DENV seropositivity in the Raebareli district of UP, to offer crucial insights into the region's effective control and management strategies. Materials and methods This study, after obtaining approval from the ethics committee, analyzed blood samples of individuals suspected of having dengue at a teaching hospitalin rural UP between January and December 2022. To determine the disease's seroprevalence, both dengue NS1 antigen ELISA and dengue IgM Microlisa were conducted. Furthermore, RT-PCR was performed on NS1-positive samples to confirm the serotypes. The collected data were analyzed using Epi Info 7.0. Results Of the 589 suspected dengue cases, 86 (14.60%) tested positive for dengue NS1 and/or IgM. Our findings showed that males (n=330, 56.03%)and adolescents and young adults (n=301, 51.1%)from rural areas (n=523, 88.4%) were predominantly affected. Cases peaked post-monsoon, and platelet levels were notably low in NS1-positive cases. Dengue serotype 2 (DEN-2) was found in all RT-PCR-positive samples. Our results revealed a dengue seroprevalence of 14.60% (n=86), which peaked in post-monsoon months. The higher incidence among males and young adults from rural areas attending the outpatient department highlights the importance of targeted interventions and community surveillance. RT-PCR confirmed the circulation of a single serotype in the region. Conclusions This study contributes crucial insights into dengue's epidemiology and clinical profile and its findings are all the more significant now as India prepares for phase 3 trials of a quadrivalent dengue-virus vaccine in 2024. Adolescent and young adult males have an increased likelihood of acquiring the virus, and this demographic can be prioritized for vaccine trials.

IJCM_299A: Clinical profile of patients with dengue: a cross-sectional study from a tertiary care hospital, Karnataka

Background: Dengue fever (DF) are among the most important mosquito- borne diseases of the Indian subcontinent and have become a major global public health concern. Its clinical manifestations of which vary from influenza- like illness (DF) to life-threatening dengue hemorrhagic fever (DHF)/dengue shock syndrome (DSS). The purpose of the study was to find out the mode of presentation, biochemical profile and complications of Dengue cases in an apical level. Objectives: 1. To identify socio-demographic characteristics and clinical features; 2. To document the disease specific management and outcomes Methodology: A cross-sectional study of admitted patients was conducted in the department of medicine and Infectious Diseases over a period of 9 months (15/2/2023 -15/11/2023). Patients aged above 18 years with serology proven (nonstructural protein 1 [NS1]/dengue immunoglobulin M [IgM]) DF were included in this study. Their Socio demographic Details, clinical and laboratory data was recorded and analyzed. Results: Preliminary Results: Out of 125 cases, - 89 (71.2 %) patients were males and 36 (28.8%) were females. - The most common presentations were fever (96%) followed by Nausea/vomiting (40%), Headache (35%) and myalgia (31%). - Dengue NS1 and IgM antibodies were positive in 87.3% and 88.12% of the patients, respectively. - the incidence of DF, DHF, and DSS was 87.2, 11.2, and 1.6% respectively. - Shock, bleeding, and elevated serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase levels predicted adverse outcome. Conclusion: DF can present with a spectrum of clinical manifestations ranging from mild self-limiting illness to severe fatal disease. It can have varied and multi-systemic manifestations which can go unrecognized. Continuous seroepidemiological surveillance is essential to control outbreak and minimize morbidity and mortality.

Atypical Dengue Outbreak in Odisha: Insights from the Entomological Investigations.

An outbreak of dengue fever struck Tikarapada village, Rayagada district (April 2020). Among 117 fever cases, 49 tested positive for the dengue NS1 antigen. To identify mosquito-related factors in the outbreak, a survey of 101 houses found Aedes breeding sites in 11.6% of containers. Aedes aegypti (79%) and Aedes albopictus (21%) emerged from collected pupae. The village exhibited high (house index = 24.8), (container index = 11.6), (pupal index = 32.7), and (Breteau index = 40.6) indices. The findings confirmed the presence of Aedes and ample breeding sites, suggesting their role in the outbreak. A report recommending integrated vector control measures was submitted to district and state health authorities.

Urinary dengue NS1 detection on Au-decorated ZnO nanowire platform

Biodetection for non-invasive diagnostics of fluids, especially urine, remains a challenge to scientists due to low target concentrations. And biological complexes of the detection target may contain contaminants that also interfere with any assay. Dengue non-structural 1 protein (Dengue NS1) is an important biomarker for dengue hemorrhagic fever and dengue shock syndrome. Here, we developed an Au-decorated nanowire platform and applied it with a sandwich fluorophore-linked immunosorbent well plate assay (FLISA) to detect Dengue NS1 in urine. For the platform, we fabricated zinc oxide (ZnO) nanowires to provide a high surface area and then coated them with gold nanoparticles (ZnO/Au nanowires) to simply modify the Dengue NS1 antibody and enhance the fluorescence intensity. Our platform employs a sandwich FLISA that exhibits high sensitivity, specifically detecting Dengue NS1 with a limit of detection (LOD) of 1.35 pg/mL. This LOD was 4500-fold lower than the LOD of a commercially available kit for Dengue NS1 enzyme-linked immunosorbent assay. We believe that our ZnO/Au nanowire platform has the potential to revolutionize the field of non-invasive diagnostics for dengue.

Seroprevalence Study of Dengue at a Tertiary Care Hospital in Jaipur, Rajasthan

Background and Aim: Dengue is one of the most severe mosquito-borne viral infection. In the absence of specific treatments and vaccines for dengue fever (DF), vector control is the only method by which the spread of dengue can be prevented. This study investigates the seroprevalence of DF cases by detecting NS1 antigen and immunoglobulin (Ig)-G and IgM antibody by enzyme-linked immunosorbent assay (ELISA) test. Materials and Methods: This study was carried out in the Department of Microbiology, at a Tertiary Care Hospital, Jaipur (Rajasthan), done between 6 months. Blood samples from clinically suspected cases of dengue were tested immediately for qualitative detection of NS1 Ag, IgM, and IgG antibodies by ELISA. Results: One thousand seven hundred and sixty-three serum samples were tested for dengue NS1 antigen, IgM, and IgG, out of which 1066 were positive for one or more serological parameters. Dengue cases for the NS1 infection are 52.53%, for the IgM infection is 33.39%, and for the IgG infection is 14.07%. Sixty-two percentage positive samples were of male patients and 57% of positive samples were from 19 to 40 years of age group (adult population) (59%). The seasonal trend showed a gradual increase in dengue-positive cases that started in September with a peak in October (46.24%). Conclusion: The monsoon and postmonsoon seasons are times of high virus activity and enhanced vector breeding. The population must thus be constantly monitored to prevent the virus from spreading further, and serological tests are crucial for making an early diagnosis. ELISA is advised for all suspected dengue patients to initiate therapy and decrease the morbidity and fatality rate.

APRI as a predictor of severe dengue fever.

The AST/platelet ratio index (APRI) is a well-researched indicator of liver fibrosis. Some studies have shown that APRI can be used as a predictor of severe dengue, but the data is limited. As dengue epidemics are common in our country with limited healthcare resources, we believe APRI can help emergency physicians/primary physicians in predicting the severity of dengue and plan for the appropriate use of limited healthcare resources. 1) To determine the utility of APRI as a predictor of severe dengue. 2) To determine the association of APRI with length of hospital stay and platelet requirement. A retrospective cross-sectional study was done on patients presented to the Emergency Medicine department at Travancore Medicity Medical College with a positive Dengue NS1 antigen or IgM antibody. We found from the univariate analysis results that ALT > 74.5 IU/L has a sensitivity of 59.6 and a specificity of 76.3 (AUC: 0.696; 95% CI: 0.606-0.786), AST > 160.5 IU/L has a sensitivity of 42.3 and a specificity of 93.7 (AUC: 0.747; 95% CI: 0.665-0.829), and APRI > 3.2 has a sensitivity of 69.2 and a specificity of 84.2 (AUC: 0.806; 95% CI: 0.72-0.884) to predict severe dengue. Patients with an APRI of >3.2 required a mean hospital stay of 5.47 days (P = 0.005); 27 (81.8%) requiring platelet transfusion had an APRI of > 3.2 (P = 0.00). APRI is a straightforward index that can be easily derived from AST and platelet values. APRI values of >3.2 can predict severe dengue with a sensitivity of 69.2 and a specificity of 84.2. APRI values of >3.2 are also associated with the length of hospital stay and requirement of platelet transfusion.

Portable Paper-Based Immunoassay Combined with Smartphone Application for Colorimetric and Quantitative Detection of Dengue NS1 Antigen.

Dengue virus (DENV) infection, which is transmitted by Aedes mosquitoes, is a major public health concern in tropical and subtropical countries. With an annual incidence of approximately 10 million cases and 20,000-25,000 deaths, particularly among children, there is an urgent need for practical diagnostic tools. The presence of dengue non-structural protein 1 (NS1) during early infection has been linked to cytokine release, vascular leakage, and endothelial dysfunction, making it a potential marker for severe dengue. Paper-based immunoassays such as lateral flow assays (LFAs) and microfluidic paper-based analytical devices (PADs) have gained popularity as diagnostic tests due to their simplicity, rapidity, inexpensiveness, specificity, and ease of interpretation. However, conventional paper-based immunoassays for dengue NS1 detection typically rely on visual inspection, yielding only qualitative results. To address this limitation and enhance sensitivity, we proposed a highly portable NS1 dengue detection assay on a Paper-based Analytical Device (PAD), namely, DEN-NS1-PAD, that integrates a smartphone application as a colorimetric and quantitative reader. The development system enables direct quantification of NS1 concentrations in clinical samples. Serum and blood samples obtained from patients were utilized to demonstrate the system prototype performance. The results were obtained immediately and can be employed for clinical assessment, both in well-equipped healthcare facilities and resource-limited settings. This innovative combination of a paper-based immunoassay with a smartphone application offers a promising approach for enhanced detection and quantification of dengue NS1 antigen. By augmenting sensitivity beyond the capabilities of the naked eye, this system holds great potential for improving clinical decision-making in dengue management, particularly in remote or underserved areas.

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

Geographic information system-aided evaluation of epidemiological trends of dengue serotypes in West Bengal, India.

West Bengal is a dengue-endemic State in India, with all four dengue serotypes in co-circulation. The present study was conceived to determine the changing trends of circulating dengue virus (DENV) serotypes in five consecutive years (2015-2019) using a geographic information system (GIS) during the dengue season in West Bengal, India. Molecular serotyping of dengue NS1 sero-reactive serum samples from individuals with ≤5 days of fever was performed using conventional nested reverse transcriptase-PCR. GIS techniques such as Getis-Ord Gi* hotspot analysis and heatmap were used to elucidate dengue transmission based on the received NS1-positive cases and vector data analysis was used to point out risk-prone areas. A total of 3915 dengue NS1 sero-positive samples were processed from most parts of West Bengal and among these, 3249 showed RNA positivity. The major circulating serotypes were DENV 3 (63.54%) in 2015, DENV 1 (52.79%) in 2016 and DENV 2 (73.47, 76.04 and 47.15%) in 2017, 2018 and 2019, respectively. Based on the NS1 positivity, dengue infections were higher in males than females and young adults of 21-30 yr were mostly infected. Getis-Ord Gi* hotspot cluster analysis and heatmap indicate that Kolkata has become a hotspot for dengue outbreaks and serotype plotting on maps confirms a changing trend of predominant serotypes during 2015-2019 in West Bengal. Co-circulation of all the four dengue serotypes was observed in this study, but only one serotype became prevalent during an outbreak. Representation of NS1-positive cases and serotype distribution in GIS mapping clearly showed serotypic shift in co-circulation. The findings of this study suggest the need for stringent surveillance in dengue-endemic areas to limit the impact of dengue and implement better vector-control strategies.

Seroprevalence and Co-infections of Different Infectious Aetiologies in Blood Culture Negative Febrile Patients Seeking Healthcare at a University Hospital in Northern India: A Cross-sectional Study

Introduction: The burden of acute febrile illness remains underestimated in many low- and middle-income countries. The rationale of this study revolves around the gaps in diagnostics for acute febrile illnesses in these regions. Aim: To highlight the seroprevalence and co-infections of different infectious aetiologies in blood culture negative febrile patients. Materials and Methods: This cross-sectional study was conducted at Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India from October 2021 to July 2022, involving 153 serum samples from patients presenting with fever for less than two weeks duration during outpatient and emergency visits. The blood culture negative samples were further tested for other aetiologies such as Leptospirosis, Dengue NS1 antigen, Dengue IgM antibody, Chikungunya, Scrub typhus IgM, and Widal, respectively. Convalescent sera were also tested for all positive Widal results. All statistical analyses were performed using Statistical Package for the Social Sciences (SPSS) statistical software (IBM SPSS version 26.0, Armonk, N.Y.). Results: Out of the 153 patients enrolled, 120 patients were tested for a panel of serological tests. The majority 52 (43.3%) were aged between 21 and 40 years. Fifty-five patients (45.8%) exhibited positivity, among which Scrub typhus was the most common aetiology with 21 (17.5%) case, followed by Leptospirosis 19 (15.8%), Dengue 10 (8.3%), Chikungunya 3 (2.5%), and Enteric fever 2 (1.7%), with no cases of malaria reported. Overall, co-infections reported in present study included 7 (5.8%) cases, of which scrub typhus and Leptospirosis were the most prevalent in 5 (4.16%) cases. Two patients (1.6%) presented with a co-infection of dengue and chikungunya. Conclusion: The diverse aetiologies causing acute febrile illness necessitate a syndrome-based disease surveillance approach, accompanied by strong clinical acumen, for the betterment of patient outcomes.

A comparative study of NS1 and IgM using enzyme-linked immunosorbent assay and immunochromatography test for detection of dengue.

Dengue is the most common arboviral infection that spreads by Aedes aegypti and Aedes albopictus mosquitoes, and is quickly gaining prominence as a major mosquito-borne viral disease. One of the major public health issues is dengue fever (DF), which can also cause dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). Therefore, this study focused on comparison of dengue antigen non-structural protein (NS1) and immunoglobulin M (IgM) using enzyme-linked immunosorbent assay (ELISA) and immunochromatography test (ICT) for detection of dengue. In a Tertiary Care Hospital (TCH), sociodemographic status of probable dengue cases from February 2021 to February 2022 was studied. The results of the Dengue Antigen NS1 and IgM ICT, Dengue NS1 Microlisa, and Dengue IgM Microlisa were compared in order to determine the effective one at managing patients and preventing complications like DHF and DSS. In distribution of 100 ICT reactive samples, 50% were NS1 reactive and 50% were IgM reactive. One hundred ICT reactive samples were further processed for IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) for both NS1 and IgM. Sensitivity and specificity of NS1 ICT were 89.3% and 71.4% and that of IgM ICT was 88% and 64.5%. As a result of antigenic cross-reactivity, false positive cases were reported. Platelet count of the patients was correlated with an optical density (OD) value of ELISA for both NS1 and IgM. In the present study, patients having low platelet count showed high OD value. In cases of severe thrombocytopenia (platelet count <50000), early diagnosis by screening ICT and confirmation by ELISA (NS1 and IgM) would reduce the complications like DHF and DSS.

Isolation and molecular detection of dengue and chikungunya virus from field-collected adult mosquitoes in Kelantan, Malaysia

Background &amp; objectives: Dengue and chikungunya infections are one of the major health problems that have plagued the human population globally. All dengue virus (DENV) serotypes circulate within Malaysia with particular serotypes dominating in different years/outbreaks. In the state of Kelantan, an increasing number of DENV and chikungunya virus (CHIKV) new cases have been reported, including several deaths. This study aimed to isolate and detect these arboviruses from adult mosquitoes in Kelantan. Methods: Adult mo squito samples were collected from January to August 2019 and were identified according to gender, species and locality. The isolation of the virus was done in C6/36 cells. Dengue NS1 antigen was carried out using direct mosquito lysate and mosquito culture supernatant. Detection and serotyping of the DENV was performed using multiplex RT-PCR and CHIKV detection using a one-step RT-PCR assay. Results: Of 91 mosquito pools, four were positive for NS1 antigen comprising two pools (2.2%) of male Ae. albopictus (Pulau Melaka and Kubang Siput) and two pools (2.2%) of Ae. aegypti (Kampung Demit Sungai). DENV 1 was detected in one pool (0.9%) of female Ae. albopictus among 114 tested Aedes pools. Two pools of 114 pools (1.7%) from both male Aedes species were positive with double serotypes, DENV 1 and DENV 2 (Pulau Melaka). However, no pool was positive for CHIKV. Interpretation &amp; conclusion: The presence of DENV and the main vectors of arboviruses in Kelantan are pertinent indicators of the need to improve vector controls to reduce arbovirus infections among people in the localities.

Prognosis of Dengue Fever based on Clinical Symptoms and Complete Blood Count in children aged 2-12 years

Objective: We aim to investigate the value of Complete Blood Counts (CBCs) and clinical symptomatology of patients in determining the prognosis of dengue fever in children aged 2-12 years. Study Design: Descriptive cross-sectional study. Place and Duration: This study was conducted in Pediatric Department, HBS General Hospital Islamabad, over 3 months period, from 15th November 22, till 15th February 23. Methodology: Patients who tested positive for either NS-1 antigen or dengue IgM antibody were enrolled in study. Demographic details of patients, clinical and hematological parameters, and daily progress of fever, serial CBCs and duration of hospital stay were recorded on a proforma. Data was analyzed using SPSS 22.00. Percentages of hematological and clinical parameters, average duration of fever and hospital stay were calculated. Results: Dengue NS-1 antigen was positive in 94% of patients. Fever was seen in 88%, thrombocytopenia and leucopenia in 88% and 53% cases respectively. Thrombocytopenia and leucopenia improved within 5 days of admission in majority of patients. Average duration of improvement of symptoms and hospital stay was 3.5 days. A weak association between duration of hospital stay and lymphocyte count at admission was observed. Conclusion: Dengue fever is a mild febrile illness in our study population. Thrombocytopenia was seen in majority of patients, yet none of them developed dengue hemorrhagic fever. Clinical symptomatology and complete blood count can act as monitoring tools in these patients. Majority of patients showed improvement in their clinical symptoms and hematological abnormalities within a week time and were discharged with follow up advised. Keywords: Complete blood count, Dengue fever, Hematological abnormalities, Leucopenia, Prognosis, Thrombocytopenia. How to Cite This: Qayyum H, Rabia M, Sohail S, Zafar T. Prognosis of Dengue Fever based on Clinical Symptoms and Complete Blood Count in children aged 2-12 years. Isra Med J. 2023; 15(2): 51-55. DOI: https://doi.org/10.55282/imj.oa1363

Kawasaki disease in an infant: a case report

Background: Kawasaki disease is an acute systemic vasculitis of childhood, with a predilection of the main coronary artery. This disease is the most frequent cause of acquired heart disease in developed countries. This report is aimed to describe the diagnosis and treatment of Kawasaki disease in an infant. Case description: A 4-month-old boy came to the emergency room on November 21, 2021, with a chief complaint of high fever for three days. His appetite has decreased since he got sick. Other complaints, such as red eyes, red lips and red rashes overall his body, occurred two days before the admission. Physical examination: the child's nutritional status was good, with bilateral non-purulent conjunctivitis, erythema and cracked lips, and polymorphous rash on the body, back, and legs. We found enlarged cervical lymph nodes and reactivation of Bacillus Calmette-Guerin (BCG) scars. The laboratory findings were as follows: HGB 10.6gr/dL, WBC 11.570/µL, PLT 335.000/µL, CRP 84mg/dL, Antigen NS-1 dengue test negative, and SARS-COV2 Antigen test negative. The echocardiography results were minimal pericardial effusion and normal coronary size. With a Harada score of 4, he was diagnosed with Kawasaki disease. Management of the patient includes breastfeeding, infusion of dextrose 5% with sodium chloride (Na Cl) 0.22%, Paracetamol infusion, Intravenous Immunoglobulin (IVIg) single dose, and Acetylsalicylic acid orally. After being discharged from the hospital, he was advised to control his condition routinely to a pediatrician. Conclusion: Kawasaki disease has been reported in a 4-month-old boy with typical clinical manifestations and successfully treated with good results.

Bio-inspired graphene nanocomposite enabled electrochemical immunosensor for detection and quantification of NS1 protein of dengue virus

Dengue is a serious illness that affects a large portion of the global population. Infection with the dengue virus may have been silent or symptomatic, making identification crucial for tracking the virus's propagation and protecting society from its catastrophic consequences. The non-structural dengue protein NS1 has been used as a biomarker in the diagnosis of dengue because it circulates widely in the blood during the acute phase of the infection and is associated with viremia. In this study, we have reported the development of an electrochemical immunosensor using nanobio-inspired platform composed of ternary nanocomposite of reduced graphene oxide (rGO), polydopamine (pDA) and gold nanoparticles (AuNPs) immobilized with Anti-NS1 antibodies for the detection of NS1 protein. The nanocomposite formation and antibody immobilization are confirmed using various microscopic, spectroscopic and electrochemical techniques. The differential pulse voltammetry (DPV) has been used to investigate the detailed electrochemical properties and immunosensing response of the developed immunosensor device. The designed immunosensor showed linear detection response for NS1 protein from 1 ng ml−1 to 100 µg ml−1 with a sensitivity of 1.78 ng ml−1 mA−1 and good shelf life. This developed immunosensor with exceptionally low detection limit revealed its potential for early diagnosis of dengue virus infection.

Enhancing blood safety: the utility of NS-1 antigen capture ELISA for detecting acute dengue infections among blood donors during peak transmission periods and the potential to curtail dengue spread

Background: Dengue fever is a viral disease transmitted by mosquitoes and affects millions of people worldwide. It can also be transmitted through blood transfusions, particularly during peak transmission periods. Methods: This was a cross sectional study which was conducted over a two-month period (June 2022 to July 2022) at a tertiary hospital blood bank. A total of 180 nonrepetitive serum samples were collected from voluntary blood donors and analyzed using the dengue NS-1 Ag Microlisa ELISA kit. Results: Among the 180 samples two samples tested positive for the dengue virus NS-1 antigen using the NS-1 antigen capture ELISA, indicating a prevalence of acute dengue virus infection among blood donors during the peak transmission period of 1.2% (2/180). Conclusions: The use of NS-1 antigen testing was shown to be useful for dengue virus detection. Routine screening of blood donors for dengue virus is not universally implemented in many countries, partly due to the lack of sensitive and specific screening tests. However, the use of serological tests, such as ELISA for dengue antibodies or NS-1 antigen, can effectively detect dengue virus in blood donors. Interventions made during peak transmission periods can help in curtailing the spread of dengue infections.

Serotype Variations and Distributions of Dengue Virus During the 2022 Outbreak in Chattogram, Bangladesh

Introduction: In the year 2022, a Dengue virus outbreak occurred nationwide in Bangladesh, including Chattogram, a port city. The purpose of this study was to identify and document the serotypes of Dengue virus and to measure the viral load of the virus positive specimens. Methods: This observational study was conducted in a tertiary care hospital of Chattogram during a period of six months from June through December, 2022. A total of 74 patients with symptoms suggestive of Dengue Fever(DF) and NS1 or IgM/IgG positive dengue patients were recruited into the study. From them clinicopathological data was collected on a case record form(CRF). Ten ml of venous whole blood was drawn in EDTA tubes then centrifuged and was sent to the laboratory at SlieaGen L.L.C in Austin, Texas, USA, for Dengue serotyping and viral load analysis by qPCR-LDT method. A total of 73 specimens were analyzed, one specimen was excluded. Ethical clearance was obtained from the hospital ethical review board, written informed consents were also taken from all subjects. Serotyping and qPCR testing data was shared by SlieaGen LLC once analysis was completed. Results: Amongst the 74 patients most were male 57(77%) and most [20(40.5%)] patients were young at 21-30 years. All had history of fever(100%), followed by body aches 67(90.5%), headache 49(66.2%) and weakness 55(74.3%). Positive NS1, IgM Dengue Ab and IgG Dengue Ab were found in 68(91.9%), 8(10.8%) and 3(4.1%) cases respectively. Frequency of serotype distributions revealed DENV 1 and DENV 3 were the most common serotypes 25(33.8%) and 16(21.6%) respectively also DENV 2 was 3(4.1%) and DENV 4 was 1(1.4%). Among 27 virus positive cases single infection DENV 1 was found in 10(13.51%) samples, DENV 3 and DENV 4 found in 1(1.4%) samples each, doubly infected (DENV 1 + DENV 2) was found in 12(16.2%) samples, triple infected (DENV 1 + DENV 2 + DENV 3) was found in 3(4.1%) samples. No virus was detected in 46(62.16%) samples. Viral load (Mean ± SD ) found in DENV 1(890974.48 ± 4156206)cp/ml, DENV 2 (33423.00 ± 9088.35)cp/ml, DENV 3(23991.12 ± 51250.18)cp/ml and DENV 4 (822.00cp/ml) in virus detected samples Conclusions: All four serotypes were found in the 2022 Dengue outbreak in Chittagong and DENV 1 and DENV 3 were common serotype. Simultaneous double and triple serotype infection in the same patients may be related with different unusual clinical features which need further documentations in future. J Bangladesh Coll Phys Surg 2023; 41: 39-43

Dengue-induced Guillain–Barre syndrome: a case series

BackgroundDengue virus is an RNA virus that is associated with a myriad of neurological manifestations. Less than 5% of patients develop neuromuscular complications. Guillain–Barre syndrome (GBS) is an uncommon neurological sequelae of dengue fever. Studies have shown acute motor axonal neuropathy (AMAN) and acute motor sensory axonal neuropathy (AMSAN) to be the most common variants associated with dengue fever in Asian countries. Very few cases have been reported from Pakistan to date.Case presentationWe present four adult patients with dengue-associated GBS. The time interval between onset of symptoms of dengue fever and development of lower limb weakness in all patients was between 6 and 20 days. Dengue was diagnosed based on either serology or dengue NS1 antigen testing. Acute inflammatory demyelinating polyneuropathy (AIDP) (n = 1), AMAN (n = 1), and AMSAN (n = 2) variants were identified. One patient had a coexisting myopathy which has not been previously reported. All patients showed good recovery after treatment with plasmapheresis or intravenous immunoglobulins.ConclusionsOur case series is valuable in contributing to the limited pool of reported cases of dengue fever complicated by GBS. Early detection of new onset symmetrical limb weakness during or after a dengue infection is imperative for early treatment and to limit disability.

Electron transmittance by means of quantum capacitive states as a signal amplification mechanism for biosensing applications

The use of quantum capacitive signals within redox switch interfaces is a sensitive and specific method for detecting biomolecules in a label-free format. Presently, an electrochemical signal amplification mechanism is demonstrated based on the adjustment of the energy level of quantum redox capacitive probes assembled at the interface to that of free redox probes added to the biological sample. This adjustment of the energy levels permits electron transmittance (in diffusionless mode) and communication with the electrode through the quantum redox capacitive states chemically assembled at the interface. This electron transport mode is owing to a quantum transmittance mechanism that promotes an enhancement of the electrochemical current of the interface. As quantum capacitive moieties can be chemically designed within neighboring biological receptors, an increase is observed in the electric signal sensitivity of the interface upon the binding of a biological analyte of interest by about a thousand times. The detection of the NS1 dengue virus biomarker was performed as a proof-of-concept of the above-described capacitive signal amplification methodology for biosensing, enabling the diagnosis of dengue in a point-of-care format within a limit-of-detection of 0.67 pg mL−1 in undiluted human serum samples.

Changing pattern of circulating dengue serotypes in the endemic region: An alarming risk to the healthcare system during the pandemic

BackgroundThe pandemic of COVID-19 has created an unprecedented burden on the healthcare system and medical communities resulting in new public health challenges. On the other hand, in tropical countries, another concern arises due to the similar spectrum of clinical manifestations between COVID-19 and dengue fever. Thus, the neglected tropical disease ‘Dengue’ writhed with more inattention. This study aims to find the effect of the COVID-19 pandemic on dengue infections in endemic areas of West Bengal, India, and their combined impact on public health. The alterations in circulating dengue serotype and their genomic diversity in different COVID-19 waves were also monitored. MethodsA total of 1782 patients were included in this study. Dengue NS1 ELISA, molecular serotyping, genotyping and their phylogenetic analysis were performed. GISaided analysis of various dengue serotypes and hotspot identification for risk maps of severe dengue in endemic zones were done. The burden of dengue fever and the sustainability of their viral strains with changing meteorological parameters in parallel to COVID-19 waves were analyzed. ResultsCo-circulation of all the four dengue serotypes with rapid change in the pattern of prevalent serotype DENV4 (Genotype-I) in the year 2020 and DENV3 (Genotype-III) in 2021 were observed, in parallel to different circulating strains of COVID-19. Spatiotemporal distribution of DENV using Geographic Information System (GIS) applications observed a serotypic shift and hotspot mapping for risk analysis detected Kolkata as a dengue hotspot, which has also reported the maximum number of COVID-19 cases. ConclusionThis study indicates the increased fitness of circulating dengue virus strains with optimal virulence as per changing environmental conditions and the inhabitant’s immunity. The high infectivity rate of both the RNA viruses and considering.the consequences of severe dengue and COVID-19 in the population of the same geographical settings is an alarming risk.