THE COPROLOGICAL DIAGNOSIS OF GASTROINTESTINAL NEMATODE INFECTIONS IN SMALL RUMINANTS

Abstract

Although representing a significant economic and welfare burden to the global ruminant livestock industry, GIN infections in small ruminants are often neglected and implementation in research, diagnosis and surveillance of these parasites is still poor, mainly in the matter of diagnostic methods and their use/interpretation. The accurate diagnosis (and interpretation) of GIN directly supports parasite control strategies and is of relevance for investigations into parasite biology, ecology and epidemiology (Roeber et al., 2013). This aspect is now particularly important given the problems associated with anthelmintic resistance (AR) in GIN populations of small ruminants worldwide (Roeber et al., 2013 a,b). Various methods are employed for the ante mortem diagnosis of GIN infections in small ruminants. These include the observation of clinical signs indicative of disease (although non-pathognomonic), coprological diagnosis (faecal egg count – FEC), biochemical and/or serological, and molecular diagnostic approaches (reviewed in Roeber et al., 2013). However, still now, faecal egg count (FEC) techniques remain the most common laboratory methods for the diagnosis of GIN in small ruminants. Also for FEC, widespread standardization of many laboratory techniques does not exist, and most diagnostic, research and teaching facilities apply their own modifications to published protocols (Kassai, 1999). Although these techniques are regarded to be standard diagnostic procedures, there is a lack of detailed studies of diagnostic performance, including the diagnostic sensitivity, specificity and/or repeatability (Roeber et al., 2013). Furthermore, many aspects concerning factors affecting FEC (e.g. season of sampling, sampling period, consistency of faeces, fecundity of worms, etc., as well as interpretation of FEC) have poorly been investigated so far. These are the reasons that motivated me in choosing “The coprological diagnosis of gastrointestinal nematode infections in small ruminants” as topic of my PhD thesis to help optimize the use and interpretation of FEC in small ruminants