201. Repurposed automated handheld counter as a point-of-care tool to identify individuals 'at risk' of serious post-ivermectin encephalopathy
- Author
-
Sébastien D. S. Pion, Samuel Wanji, Sasisekhar Bennuru, Joseph Kamgno, and Thomas B. Nutman
- Subjects
Male ,Cell Count ,medicine.disease_cause ,Onchocerciasis ,Global Health ,Gastroenterology ,Brugia malayi ,Loa ,Ivermectin ,Malondialdehyde ,Medicine and Health Sciences ,Public and Occupational Health ,Cameroon ,Microfilariae ,Lymphatic filariasis ,Whole blood ,Brain Diseases ,biology ,Antiparasitic Agents ,lcsh:Public aspects of medicine ,Filariasis ,Wuchereria bancrofti ,Infectious Diseases ,Helminth Infections ,Loa loa ,medicine.drug ,Research Article ,Neglected Tropical Diseases ,medicine.medical_specialty ,lcsh:Arctic medicine. Tropical medicine ,Infectious Disease Control ,lcsh:RC955-962 ,Point-of-Care Systems ,Loiasis ,Internal medicine ,parasitic diseases ,medicine ,Parasitic Diseases ,Animals ,Humans ,Disease Eradication ,Adverse effect ,business.industry ,Lymphatic Filariasis ,Public Health, Environmental and Occupational Health ,lcsh:RA1-1270 ,biology.organism_classification ,medicine.disease ,Tropical Diseases ,Immunology ,business ,Papio - Abstract
Introduction Administration of ivermectin (IVM) as part of mass drug administration (MDA) campaigns for onchocerciasis and/or lymphatic filariasis (LF) has been suspended in areas co-endemic for Loa loa due to severe post-treatment adverse events (SAEs) associated with high-burden of infection (>30,000 mf/ml). One simple approach for preventing SAEs is to identify and exclude individuals at risk from MDA. Here, we describe a repurposed hand-held automated cell counter (Scepter 2.0; HHAC) as a rapid, point-of-care method for quantifying microfilariae (mf) in the blood of infected individuals. Methodology/Principal Findings The quantification of microfilarial levels in blood of naturally infected humans, experimentally infected baboons, or mf-spiked human blood was tested using a microfluidic-based automated counter and compared to traditional calibrated thick-smears. We demonstrate that mf can be quantified in 20 µl of whole blood following lysis with 10% saponin within a minute of obtaining blood. There was a highly significant concordance between the counts obtained by the HHAC and those by microscopy for mf densities of >5,000 (p30,000 per ml (p, Author Summary Mass drug administration (MDA) efforts with ivermectin-based regimens for onchocerciasis and for lymphatic filariasis in Africa have been suspended in certain areas that are co-endemic for Loa loa infection. This is due to the serious adverse events (encephalopathy and death) that can develop following ivermectin administration in individuals with very high circulating levels of Loa loa microfilariae (mf) (>30,000 mf/ml). Currently thick-blood smears are performed to quantify the mf levels that are neither rapid nor high throughput. To develop a point of care (POC) strategy for rapid and high throughput mf quantification, a repurposed handheld automated counter (HHAC) was assessed and shown to be an efficient POC tool to identify individuals with very high Loa loa microfilaraemia in a manner sufficient to be used as part of a Test and (not) Treat (TNT) program in an effort to restart the suspended MDA programs while preventing severe adverse neurologic events.
- Published
- 2014