Antigen Positivity Without Infection: Confirmatory Mapping in Children Rules out Lymphatic Filariasis in Loiasis Co-Endemic Settings in Gabon.
5 affiliations
- 1Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN), World Health Organization Regional Office for Africa, Brazzaville P.O.Box 06, Congo.
- 2Programme for the Control of Parasitic Diseases, Ministry of Health, Libreville P.O.Box 820, Gabon.
- 3World Health Organization Country Office, Libreville P.O.Box 820, Gabon.
- 4The END Fund, New York, NY 10016, USA.
- 5National Neglected Tropical Diseases Control Programme, Ministry of Health, Ouagadougou 03 BP 7009, Burkina Faso.
Abstract
Precise mapping is essential for guiding lymphatic filariasis (LF) elimination programmes, yet antigen tests in loiasis co-endemic settings must be read with caution because of cross-reactivity. Gabon's 2015 national mapping flagged 18 of 52 health districts (HDs) as potentially endemic, but that signal needed confirmation before committing populations to mass drug administration (MDA). We surveyed all 18 HDs between July and August 2025, enrolling 6688 children aged 9-14 years from 341 communities and testing them with the STANDARD™ Q Filariasis Antigen Test (QFAT); every QFAT-positive child then underwent nocturnal calibrated thick-smear microscopy and Wb-LDR quantitative PCR (qPCR) on dried blood spots. Thirteen children (0.19%) were QFAT-positive across eight HDs, and 17 of 18 HDs fell below the confirmatory mapping threshold for MDA. None of the thirteen carried Wuchereria bancrofti microfilariae or DNA; microscopy instead identified Loa loa in three and Mansonella perstans in one. MDA for LF is not warranted in the surveyed HDs, and these findings show why antigen results in loiasis co-endemic settings require parasitological or molecular confirmation before any programmatic decision.
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BibTeX
@article{bakajika2026antigen,
title = {{Antigen Positivity Without Infection: Confirmatory Mapping in Children Rules out Lymphatic Filariasis in Loiasis Co-Endemic Settings in Gabon.}},
author = {Didier Bakajika and Julienne Atsame and Jeremie Rody Pambou and Philemon Koumba Koumba and Sylvie Alberte Ntsame Ella and Rychy Fustel Kombila Kombila and Davi Mawule and Ghislaine Nkone Asseko and Kelly Zongo and Mamadou Serme and Ambroise Bonkoungou and Sanon Karim and Moussa Sounkalo Sanfo and Aime Adjami and Dyesse Yumba and Honorat Zouré and Jorge Cano and Elizabeth Juma},
journal = {Tropical medicine and infectious disease},
year = {2026},
month = sep,
doi = {10.3390/tropicalmed11100261},
url = {https://europepmc.org/article/MED/42931446},
note = {CC BY},
}
RIS
TY - JOUR
TI - Antigen Positivity Without Infection: Confirmatory Mapping in Children Rules out Lymphatic Filariasis in Loiasis Co-Endemic Settings in Gabon.
AU - Didier Bakajika
AU - Julienne Atsame
AU - Jeremie Rody Pambou
AU - Philemon Koumba Koumba
AU - Sylvie Alberte Ntsame Ella
AU - Rychy Fustel Kombila Kombila
AU - Davi Mawule
AU - Ghislaine Nkone Asseko
AU - Kelly Zongo
AU - Mamadou Serme
AU - Ambroise Bonkoungou
AU - Sanon Karim
AU - Moussa Sounkalo Sanfo
AU - Aime Adjami
AU - Dyesse Yumba
AU - Honorat Zouré
AU - Jorge Cano
AU - Elizabeth Juma
PY - 2026
DA - 2026/09/23
JO - Tropical medicine and infectious disease
DO - 10.3390/tropicalmed11100261
UR - https://europepmc.org/article/MED/42931446
AB - Precise mapping is essential for guiding lymphatic filariasis (LF) elimination programmes, yet antigen tests in loiasis co-endemic settings must be read with caution because of cross-reactivity. Gabon's 2015 national mapping flagged 18 of 52 health districts (HDs) as potentially endemic, but that signal needed confirmation before committing populations to mass drug administration (MDA). We surveyed all 18 HDs between July and August 2025, enrolling 6688 children aged 9-14 years from 341 communities and testing them with the STANDARD™ Q Filariasis Antigen Test (QFAT); every QFAT-positive child then underwent nocturnal calibrated thick-smear microscopy and Wb-LDR quantitative PCR (qPCR) on dried blood spots. Thirteen children (0.19%) were QFAT-positive across eight HDs, and 17 of 18 HDs fell below the confirmatory mapping threshold for MDA. None of the thirteen carried Wuchereria bancrofti microfilariae or DNA; microscopy instead identified Loa loa in three and Mansonella perstans in one. MDA for LF is not warranted in the surveyed HDs, and these findings show why antigen results in loiasis co-endemic settings require parasitological or molecular confirmation before any programmatic decision.
SN - 2414-6366
ER -