Incidence of loiasis clinical manifestations in a rural area of the Republic of Congo: Results from a longitudinal prospective study (the MorLo project).

Bibliographic Details
Title: Incidence of loiasis clinical manifestations in a rural area of the Republic of Congo: Results from a longitudinal prospective study (the MorLo project).
Authors: Jérémy T Campillo, Biam-Miveck Pakat-Pambou, Bachiratou Sahm, Sébastien D S Pion, Marlhand C Hemilembolo, Elodie Lebredonchel, Michel Boussinesq, François Missamou, Cédric B Chesnais
Source: PLoS Neglected Tropical Diseases, Vol 19, Iss 2, p e0012868 (2025)
Publisher Information: Public Library of Science (PLoS), 2025.
Publication Year: 2025
Collection: LCC:Arctic medicine. Tropical medicine
LCC:Public aspects of medicine
Subject Terms: Arctic medicine. Tropical medicine, RC955-962, Public aspects of medicine, RA1-1270
More Details: BackgroundLoiasis is endemic in Central Africa. Despite evidence of clinical complications and increased mortality, it remains excluded from the list of neglected tropical diseases. The main manifestations are Calabar swellings (CS), Eyeworm (EW) and non-specific general symptoms such arthralgia and pruritus. We calculated incidence rates for clinical manifestations of loiasis from a 13-month study on clinical manifestations in 991 individuals living in Loa loa-endemic areas in the Republic of Congo.MethodologyFrom September 2022 to September 2023, community health workers collected weekly symptoms from cohort participants. Detailed data on symptom duration, intensity, associated pruritus, and impact on sleep were recorded. Laboratory procedures included thick blood smear for L. loa microfilaremia measurement, creatininemia measurement and eosinophilia counts. We used multiple failure analysis and frailty models to calculate incidence rates of EW, CS, arthralgia, pruritus and absence from work (AfW) and to analyses factors associated with increased incidence of each symptom. The population-attributable fractions (PAFs) associated with loiasis were also calculated for pruritus, AfW and arthralgia.Principal findingsAmong the studied manifestations, arthralgia had the highest incidence rate at 555.2 cases per 1000 Person-Year (PY), followed by pruritus (332.3 cases/1000 PY), AfW (298.6/1000 PY), EW (266.4/1000 PY), and CS (213.8/1000 PY). Notably, the incidence rates of CS, pruritus, arthralgia, and AfW were statistically significantly higher in the subgroup of individuals who experienced at least one episode of EW during the follow-up period. EW occurrence is more frequent when microfilaremia is present. The PAFs of AfW, pruritus and arthralgia, associated with loiasis was 18.0% [07.3-27.6], 20.8% [11.6-29.1] and 12.1% [3.1-20.1], respectively.Conclusion/significanceThis is the first study to provide incidence rates for the clinical manifestations of loiasis. These estimates are crucial for assessing the burden of loiasis. The findings highlight the disease's impact on quality of life.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1935-2727
1935-2735
Relation: https://doaj.org/toc/1935-2727; https://doaj.org/toc/1935-2735
DOI: 10.1371/journal.pntd.0012868
Access URL: https://doaj.org/article/9437c4e09a834cf6bc9f65914f501d79
Accession Number: edsdoj.9437c4e09a834cf6bc9f65914f501d79
Database: Directory of Open Access Journals
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More Details
ISSN:19352727
19352735
DOI:10.1371/journal.pntd.0012868
Published in:PLoS Neglected Tropical Diseases
Language:English