Dengue fever is a mosquito-borne disease caused by four related but antigenically
distinct dengue viruses. In the last half-century, the prevalence of dengue
fever has increased dramatically (up to 30%) worldwide, especially in
Sub-Saharan Africa. In Burkina Faso, the last dengue epidemic occurred in 2016,
and the epidemiological situation is still poorly documented at the national
level. Therefore, the present study aimed to conduct a sentinel seroepidemiology
of suspected dengue virus infections from 2017 to 2020 at Charles de
Gaulle University Pediatric Hospital Center of Ouagadougou. This investigation
was designed to be a descriptive and analytical study. Patients with suspected
cases of dengue fever were recruited from January 2017 to December
2020 during general medicine consultation and referred to Charles de Gaulle
University Pediatric Hospital Center of Ouagadougou for the serological diagnosis
of dengue. Venous blood was collected in dry or EDTA tubes and tested
for DENV NS1 antigen, anti-dengue IgM, and anti-dengue IgG using SD Bioline
Dengue Duo Rapid Detection Kit (Standard Diagnostic Inc., Korea). A total
of 3400 blood samples from clinically suspected dengue cases were analyzed,
of which 1784 (52.5%) were males, and 1616 (47.5%) were females. Among
the 3400 patients included in the study, 661 (19.4%) were tested at least positive
for NS1 antigen, anti-dengue IgM or anti-IgG. Among them, individuals
positive for IgG suggesting past dengue virus infection were found in more
than a third of 262 (7.7%) of the cases. Approximately, 80.0% (2705/3400)
dengue suspected cases and 85.5% (341/399) early or primary dengue infections
were recorded in the last four months of the study (September to December
2020), with a peak in mid-October and mid-November. There was no
statistically significant difference in seroprevalence between males and females (p = 0.7), but an increasing seropositivity trend with age, from 11.6%
for the patient under 5 years group to 39.7% for 30 years and over age group
were noted. This study puts in evidence a considerable level of transmission
of dengue viruses in Burkina Faso and provides baseline seroprevalence data.
The recurrent outbreaks of dengue infection in multiple geographical areas
need comprehensive surveillance and a diagnostic system to identify the actual
burden and pinpoint the risk factors. A larger study is, therefore, needed
to determine the actual prevalence of dengue in Burkina Faso and map the serotypes.

Dengue Seroepidemiology Ouagadougou