Use of Wb123 rapid tests for monitoring lymphatic filariasis elimination in Kolokoba, Mali

Abstract

Abstract
Introduction: Mass drug administration targeting
Wuchereria bancrofti was stopped in 2008 after six annual
rounds in six endemic villages in the Kolokoba health area,
with epidemiological coverage ≥ 65%. In 2009,
surveillance was introduced in these villages to detect any
re-emergence of the infection, using two types of rapid
test. Methods: We conducted a cross-sectional study in
2019. A total of 219 children (6-7 years) and 1827 adults
(15 years and older) were included in the six villages.
Filarial test trip (FTS) and Biplex SD Bioline (Wb123/ov16)

were used to detect antigen of W. bancrofti and antibodies
against O. volvulus/W. bancrofti, respectively. Participants
who tested positive using FTS were tested using night
blood thick smears to look for microfilariae. Results:
Among the 2,046 participants, the prevalence of
antigenemia varied from 0% to 2.94% with FTS and to 0%
to 0.87% using Wb123. The highest prevalence was
observed in Niatanso with 2.94% in men and 2.35% in
women. No positive microfilaremia was observed in any
of the villages. Onchocerca volvulus positive serology was
detected in 0.54% of people aged 15 and above.
Conclusion: Seroprevalence with Biplex Wb123/ov16
was comparable with the prevalence of antigenemia using
FTS. Consequently, the importance of considering this
antibody test, which has the advantage of simultaneously
measuring exposure to onchocerciasis in co-endemic
areas.