Epidemiology of Dengue in patients with febrile syndrome at Saint Camille Hospital, Ouagadougou, Burkina Faso from 2020 to 2

: Dengue is still a public health problem in tropical countries. This disease, which had almost disappeared in some areas of the world, has become re-emergent in certain parts of the world including Africa.The aim of this study is to determine the seroprevalence and evolution of Dengue virus (DENV) infection from 2020 to 2021 at the Hospital Saint Camille de Ouagadougou (HOSCO), Burkina Faso. Methodology: This was a descriptive analytical study of patients seen in general practice with febrile syndrome referred for serological diagnosis of Dengue at the HOSCO laboratory over a period of 2 years (January 1, 2020 ­ December 31, 2021). The "Dengue Duo (AgNS1/IgM/IgG)" kit from SD Bioline was used for the rapid diagnosis through the detection of NS1 antigen and IgM/IgG antibodies in plasma. Data were analysed with SPSS version 20.0 software. Association between demographic data and prevalence of DENV infection was determined by Chisquare test and odds ratio (with 95% confidence interval). P value less than 0.05 was considered statistical significance. Results: A total of 2957 patients aged 0-94 years were referred for serological diagnosis of DENV infection at the HOSCO laboratory over the period 2020-2021, comprising 56.3% females and 43.7% males. The overall prevalence of acute DENV infection (NS1Ag positive) was 5.4% (159/2957), with 2.4% (41/1700) in 2020 and 9.4% (118/1257) in 2021 (OR=4.192, 95% CI=2.915-6.028, p<0.0001). The prevalence of acute DENV infection of 7.0% (91/1292) in the males was significantly higher than 4.1% (68/1665) in the females (OR=1.779, 95% CI=1.288-2.458, p=0.0005), and also significantly higher in age groups 20-29 years (7.6%), 10-19 years (6.9%) and 40-49 years (5.8%) than other age groups (X 2=14.928, p=0.0107). The overall prevalence of DENV IgM and IgG antibodies was 3.2% and 37.3% respectively. The prevalence of DENV IgG antibodies was significantly higher in males (44.0%) than females (32.1%) (OR=1.667, 95%CI=1.434-1.938, p<0.0001) and in age groups 30-39 (43.4%), 40-49 (44.0%) and >50 years (49.3%) than other age groups (X2=121.0, p<0.0001), indicating that past exposure to DENV infection is higher among males and older age groups. The peak of DENV infection was between October and November with 84.3% (134/159) of NS1Ag positivity occurring during this period. Conclusion: The present study reports a high prevalence of acute Dengue virus infection in patients from October to November. To eradicate Dengue which has become a tropical silent epidemic, interventions such as vector control, availability of and accessibility to diagnostic tests, and good therapeutic management are of great importance

Whether Platelet Count Really Influences the Outcome of Dengue Patients? A Study Done at Tertiary Care Centre in North Karnataka Region

In many parts of India, Dengue has become a major public health problem and Kalaburagi District in North Karnataka region was previously not known to be an endemic area for dengue. Three clinical syndromes, classic dengue fever, dengue haemorrhagic fever and dengue shock syndrome are seen with dengue virus infection. This present study was undertaken to find out whether platelet count really influences the outcome of dengue patients in a tertiary health care centre in Kalaburagi, Karnataka.METHODSAbout hundred patients admitted in our hospital with positive Dengue NS1 and Dengue IgM were selected. The follow up of patients is done from the onset of fever to up to twelve days or until their recovery according to discharge criteria of WHO whichever of them is earlier.RESULTSIn this study, 100 cases were studied, out of which Dengue fever was seen in 73 cases, Dengue Hemorrhagic Fever in 17 cases and Dengue Shock Syndrome in 10 cases was seen based on WHO criteria. In this study, 99 percent patients had fever. In this study 73 percent of patients were Dengue NS1 Positive and 27 percent of patients were Dengue IgM Positive. In present study, continuously increasing pattern of platelet count was seen in 55 percent cases; initial fall then rise of platelet count was seen in 38 percent cases and persistently low pattern of platelet count was seen in 7 percent cases. This study showed that 30 percent of patients had bleeding manifestations and bleeding manifestations were maximum in patients having low platelet counts. In the present study, 92% cases improved and 8% cases expired.CONCLUSIONSAmong the three clinical syndromes, Dengue fever was more common than dengue haemorrhagic fever and dengue shock syndrome. It was found that platelet count influenced the outcome of dengue patients. Management of dengue case is mainly supportive

Evaluation of a novel immuno-magnetic assay technology for rapid detection of dengue NS1 antigen

Background: Serological diagnosis of dengue fever is based on the detection of NS1 antigen and further confirmed by the assay of dengue IgM and IgG. Rapid Diagnostic Tests (RDTs) are no longer recommended for use by the Government of India. However, there is a requirement of rapid results without compromising on the test quality. Accordingly, we undertook an evaluation of a novel cartridge-based system employing a unique table-top diagnostic device for dengue NS1 antigen by BluSense Diagnostics incorporating a patented Immuno-Magnetic Assay (IMA).Methods: A total of 309 samples were tested on unlinked anonymous basis. Each sample was tested using NS1 Ag ELISA (Microlisa, J. Mitra), ViroTrack and NS1 RDT (SD Alere) and results were recorded. Discordant samples were further tested by dengue NS1 AG ELISA (Panbio) and dengue IgG/IgM Maclisa (J. Mitra).Results: When compared with approved ELISA kits used globally the Virotrack test returned a sensitivity of 94.74%; specificity of 97.44%; PPV of 97.30%; NPV of 95% and accuracy of 96.10%. Hourly throughput is 5-6 samples.Conclusions: The Virotrack system is highly suitable as a POCT module in HCFs with low to moderate workload that employs novel technology, is rapid, user friendly and comparable to the ELISA in sensitivity and specificity. The equipment is user friendly and can work both on plasma/serum and whole blood. Model with multiple modules (3-4) will improve the throughput and turnaround time. Evaluation of this novel technology has been done in India for the first time.

A new method for rapid detection of dengue antigen based on microfluidic immune magnetic beads / 热带医学杂志

@# Abstract：Objective To establish a sensitive，rapid and convenient method for the detection of dengue antigen and assist clinical diagnosis of dengue. Methods In this paper，we developed a rapid detection method for dengue antigen based on microfluidic immune magnetic beads. Solidwork software was used to design microfluidic chip，which was prepared by mechanical processing and chemical sealing. Immunomagnetic beads of dengue antibody were prepared by chemical coupling reaction. Using HRP ⁃TMB ⁃H2O2 as color system，dengue NS1 antigen was detected on microfluidic chip carrier by double antibody sandwich method. Finally，57 clinical samples were tested by the novel method and traditional ELISA kit，and the accuracy of the method was analyzed，and the advantages and disadvantages of the two methods were compared. Results 20 minutes was needed to detect dengue NS1 antigen by using the novel ELISA method，and the reaction system only needed 10 μg beads and 10 μL samples. In the verification experiment，the method could distinguish the negative from the positive obviously. The positive sample had color rendering，while the negative and blank samples had no color rendering. In terms of detection performance，the coincidence rate between the new ELISA method and the traditional ELISA method reached 100%. Conclusion The novel ELISA detection platform had the advantages of simple，rapid，reagent and sample saving，high sensitivity，good stability and high accuracy，and could be used for the detection of dengue antigen.