Using dried blood spots stored on filter paper to measure cholinesterase activity in wild avian species

Abstract

Birds of prey that are poisoned by cholinesterase inhibitors (e.g. organophosphate and carbamate insecticides) are often cared for at animal shelters, rehabilitation centres and wildlife diagnostic facilities. Plasma cholinesterase (ChE) activity is a recognized method of assessing exposure to these insecticides, but standard blood-handling protocols are difficult to follow in non-laboratory settings. The primary objective of this study was to expand upon a method for storing human blood on filter paper without the need for complicated equipment or refrigeration, and to test its utility for measurement of ChE activity in avian blood. ChE activity from whole blood, plasma, and dried blood spots was analysed from 169 wild birds and comparisons made among sample types. ChE activity measured in whole blood haemolysates and dried blood spots were significantly correlated (r = 0.74, p < 0.001), as was ChE activity measured in plasma and dried blood spots (r = 0.68, p < 0.001). This study demonstrated that monitoring pesticide exposure in birds could be conducted using elementary blood sampling, preserving and shipping techniques.

Blood Collected on Filter Paper for Wildlife Serology: Evaluating Storage and Temperature Challenges of Field Collections

“…Nobuto FP strips are made of high-purity cellulose, are highly absorbent and uniform quality, and are recommended for several veterinary serology applications (Toyo Roshi Kaisha, Ltd.). Studies of the effects of storage on FP samples differ considerably in design, and some results are challenging to compare (e.g., Beard and Brugh 1977;Banks 1985;McDade et al 2000); however, evidence from animals and humans indicates that antibodies in whole-blood FP samples generally withstand storage and temperature challenges better than some other analytes (McDade et al 2007;Trudeau et al 2007). A drop in test sensitivity after prolonged sample storage could reflect a characteristic of the assay, a technical or reagent issue, or loss of analyte stability.…”

“…More specifics have been published in blood-spot guidelines and reviews (NCCLS 2003;McDade et al 2007), studies from the tropics (e.g., Punnarugsa and Mungmee 1991;Ruangturakit et al 1994) and elsewhere (e.g., Corran et al 2008;Mei et al 2011), and a few animal reports (e.g., Brugh and Beard 1980;Trudeau et al 2007). However, the vast majority of sources focus on human blood spots that are dried and analyzed from small FP discs, and we found only one source that assessed effects of freezing FP blood samples directly upon collection (Behets et al 1992).…”

Programme de réhabilitation des oiseaux de proie au Québec : bilan 1986-2013

“…Nos résultats reflètent les cycles d'incursion du harfang des neiges (Bubo scandiacus) La manipulation d'une grande quantité d'oiseaux de proie donne accès aux tissus nécessaires à certaines études. Par exemple, une étude échelonnée sur plusieurs années a été réalisée en partie avec des échantillons provenant de l'UQROP et du CQSAS pour l'analyse sur les rodenticides (Thomas et collab., 2011), le mercure (voir l'article à ce sujet dans le présent numéro) et les pesticides agissant sur les cholinestérases (Trudeau, 2007).…”

Dried blood spots in toxicology: from the cradle to the grave?

“…putting it in a box or bag with desiccant, taking care that the blood spots do not come into contact with other surfaces. This approach of pro-active drying has already been applied in field studies where blood was sampled from wild birds (Trudeau et al, 2007). Rapid sampling is particularly relevant in cases in which the half-life of a drug is short.…”

“…Assessment of cholinesterase activity in DBS of avian species has been found sensitive enough to serve as a diagnostic tool for identifying exposure to cholinesterase-inhibiting pesticides. DBS sampling of animals allows the collection of samples at remote areas and in non-specialized centres, where no special equipment like a centrifuge is available and where proper storage of a blood sample is difficult (Trudeau et al, 2007). A recent initiative in the context of monitoring exposure of animals to toxic substances, somewhat paralleling the efforts done for evaluating a newborn's exposure to environmental contaminants via DBS, is DABSE ("Database for avian blood spot examination") (Shlosberg et al, 2011a).…”