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

Incidence of dengue virus infections in febrile episodes in Ile-Ife, Nigeria

Background: Dengue viruses have been identified as the most important arboviral pathogen in the world. They are transmitted by mosquitoes of Aedes species. While dengue infection is accompanied by little or no subclinical signs in many; about 1-2% may produce clinically severe Dengue Haemorrhagic Fever/Dengue Shock Syndrome. Early recognition; appropriate treatment and elimination of mosquito vectors will help control it. The study is aimed at determining the incidence of dengue infections in Ile-Ife. Materials and Methods: Three millilitres venous blood was collected from each of one hundred and seventy nine patients presenting with fever in the last two weeks; and analyzed for the presence of anti-dengue IgM antibodies using Dengue Virus IgM ELISA kit (DIA.PRO; Italy) according to the manufacturer's instructions while the results and demographic data were analyzed using SPSS version 16. Results: It was observed that 46 (25.7%) of the 179 had detectable IgM antibodies to dengue virus with 9 of them having no detectable malaria parasite. The incidence was 26.5% and 25% in male and female respectively. Further studies will be necessary to confirm the relatedness of blood transfusion as an important risk factor to the transmission of dengue virus.Conclusion: The study established the presence of fresh dengue infections for the first time in Ile-Ife among different groups of people. Clinicians are advised to prioritize laboratory diagnosis; especially of fever

Emergence and Global Spread of a Dengue Serotype 3; Subtype III Virus

Over the past two decades; dengue virus serotype 3 (DENV-3) has caused unexpected epidemics of Dengue hemorrhagic fever (DHF) in Sri Lanka; East Africa; and Latin America. We used a phylogenetic approach to evaluate the roles of virus evolution and transport in the emergence of these outbreaks. Isolates from these geographically distant epidemics are closely related and belong to DENV-3; subtype III; which originated in the Indian subcontinent. The emergence of DHF in Sri Lanka in 1989 correlated with the appearance there of a new DENV-3; subtype III variant. This variant likely spread from the Indian subcontinent into Africa in the 1980s and from Africa into Latin America in the mid-1990s. DENV-3; subtype III isolates from mild and severe disease outbreaks formed genetically distinct groups; which suggests a role for viral genetics in DHF