Automated detection of Loa loa: a field trial in Cameroon
- 1University of Washington, Seattle, WA
Abstract
Onchocerciasis (river blindness) is targeted for elimination through mass administration (MDA) of ivermectin (IVM) to endemic populations. In areas where loiasis, caused by the blood-borne filarial parasite Loa loa, is co-endemic, IVM MDA faced significant challenges because individuals harboring more than 30,000 L. loa microfilaria (mf)/mL of blood are at high risk of developing serious adverse events (SAEs) that can sometimes be fatal. An alternative strategy was developed for safe IVM distribution: the so-called 'Test and Not Treat' (TaNT), which identifies and excludes individuals with high mf density from IVM MDA and treats only those with minimal risk. TaNT requires a point-of-care diagnostic device to rapidly quantify L. loa parasites in field conditions. The NTDscope is a handheld device which captures bright-field videos of whole blood in capillaries. An onboard algorithm detects and counts the live microfilaria of L. loa via movement of red blood cells. This paper describes (i) a new detection algorithm; and (ii) a May 2025 field trial in Cameroon using the NTDscope with new algorithm (550 patients). Results for the TaNT use case (i.e. flagging cases with L. loa mf densities > 30,000 mf/mL): 94% to 97% sensitivity, and 94% to 97% specificity. The results indicate that the NTDscope and new algorithm provide a greater margin of safety than the predecessor device, and can potentially offer rapid, effective field detection of high mf infections to enable scalability of the TaNT strategy.
Related
- Automated intermittent olfactory stimulation to reduce apnea in preterm infants: results of the PREMODEUR randomized clinical trial
- ECG-based automated detection of sleep apnea using deep neural networks and hidden markov models
- Automated corneal endothelial cell detection and segmentation in specular microscopy images using Attention and Faster U-Net
- An Arduino-Based Butane Leak Detection System With Automated Ventilation and Internet of Things (IoT) Mobile Application
- Validation of a Revised V-Slope Algorithm for Automated First Ventilatory Threshold Detection in Healthy Adults
BibTeX
@misc{djuneyemeli2026automated,
title = {{Automated detection of Loa loa: a field trial in Cameroon}},
author = {L. Djune-Yemeli and C. B. Delahunt and S. M. Tchana and J. G. Bopda and Y. A. Balog and Y. Y. Nzeuhang and D. Banik and M. D. Keller and E. Spencer and M. D. de Leon Derby and Z. L. Moussa and D. A. Fletcher and I. I. Bogoch and A.-L. M. Le-Ny and J. Kamgno},
howpublished = {bioRxiv},
year = {2026},
month = aug,
doi = {10.64898/2026.08.29.745114},
url = {https://www.biorxiv.org/content/10.64898/2026.08.29.745114v1},
note = {CC BY-NC},
}
RIS
TY - UNPB
TI - Automated detection of Loa loa: a field trial in Cameroon
AU - L. Djune-Yemeli
AU - C. B. Delahunt
AU - S. M. Tchana
AU - J. G. Bopda
AU - Y. A. Balog
AU - Y. Y. Nzeuhang
AU - D. Banik
AU - M. D. Keller
AU - E. Spencer
AU - M. D. de Leon Derby
AU - Z. L. Moussa
AU - D. A. Fletcher
AU - I. I. Bogoch
AU - A.-L. M. Le-Ny
AU - J. Kamgno
PY - 2026
DA - 2026/08/29
PB - bioRxiv
DO - 10.64898/2026.08.29.745114
UR - https://www.biorxiv.org/content/10.64898/2026.08.29.745114v1
AB - Onchocerciasis (river blindness) is targeted for elimination through mass administration (MDA) of ivermectin (IVM) to endemic populations. In areas where loiasis, caused by the blood-borne filarial parasite Loa loa, is co-endemic, IVM MDA faced significant challenges because individuals harboring more than 30,000 L. loa microfilaria (mf)/mL of blood are at high risk of developing serious adverse events (SAEs) that can sometimes be fatal. An alternative strategy was developed for safe IVM distribution: the so-called 'Test and Not Treat' (TaNT), which identifies and excludes individuals with high mf density from IVM MDA and treats only those with minimal risk. TaNT requires a point-of-care diagnostic device to rapidly quantify L. loa parasites in field conditions. The NTDscope is a handheld device which captures bright-field videos of whole blood in capillaries. An onboard algorithm detects and counts the live microfilaria of L. loa via movement of red blood cells. This paper describes (i) a new detection algorithm; and (ii) a May 2025 field trial in Cameroon using the NTDscope with new algorithm (550 patients). Results for the TaNT use case (i.e. flagging cases with L. loa mf densities > 30,000 mf/mL): 94% to 97% sensitivity, and 94% to 97% specificity. The results indicate that the NTDscope and new algorithm provide a greater margin of safety than the predecessor device, and can potentially offer rapid, effective field detection of high mf infections to enable scalability of the TaNT strategy.
ER -