Evaluation using latent class models of the diagnostic performances of three ELISA tests commercialized for the serological diagnosis of Coxiella burnetii infection in domestic ruminants

T. Lurier (1, 2) , Elodie Rousset (3) , Patrick Gasqui (1, 2) , Carole Sala (4) , Clément Claustre (1, 2) , David Abrial (1, 2) , Philippe Dufour (3) , Renée de Crémoux (5) , Kristel Gache (6) , Marie Laure Delignette-Muller (7) , Florence Ayral (8, 2) , Elsa Jourdain (1, 2)

1 UMR EPIA - Unité Mixte de Recherche d'Épidémiologie des maladies Animales et zoonotiques
2 INRAE - Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement
3 Laboratoire de Sophia Antipolis
4 Laboratoire de Lyon [ANSES]
5 IDELE - Institut de l'élevage
6 GDS France - Fédération nationale des Groupements de Défense Sanitaire
7 LBBE - Laboratoire de Biométrie et Biologie Evolutive - UMR 5558
8 RS2GP - Rongeurs Sauvages, Risques Sanitaires et Gestion des Populations - UR 1233

ELISA methods are the diagnostic tools recommended for the serological diagnosis of Coxiella burnetii infection in ruminants but their respective diagnostic performances are difficult to assess because of the absence of a gold standard. This study focused on three commercial ELISA tests with the following objectives (1) assess their sensitivity and specificity in sheep, goats and cattle, (2) assess the between-and within-herd seroprevalence distribution in these species, accounting for diagnostic errors, and (3) estimate optimal sample sizes considering sensitivity and specificity at herd level. We comparatively tested 1413 cattle, 1474 goat and 1432 sheep serum samples collected in France. We analyzed the cross-classified test results with a hierarchical zero-inflated beta-binomial latent class model considering each herd as a population and conditional dependence as a fixed effect. Potential biases and coverage probabilities of the model were assessed by simulation. Conditional dependence for truly seropositive animals was high in all species for two of the three ELISA methods. Specificity estimates were high, ranging from 94.8% [92.1; 97.8] to 99.2% [98.5; 99.7], whereas sensitivity estimates were generally low, ranging from 39.3 [30.7; 47.0] to 90.5% [83.3; 93.8]. Betweenand within-herd seroprevalence estimates varied greatly among geographic areas and herds. Overall, goats showed higher within-herd seroprevalence levels than sheep and cattle. The optimal sample size maximizing both herd sensitivity and herd specificity varied from 3 to at least 20 animals depending on the test and ruminant species. This study provides better interpretation of three widely used commercial ELISA tests and will make it possible to optimize their implementation in future studies. The methodology developed may likewise be applied to other human or animal diseases.

Mots clés: Q fever; Latent class model; Bayesian; Diagnostic accuracy; Herd sensitivity; Conditional dependence; Cattle; Sheep; Goats

Domaines: Sciences du Vivant [q-bio]

T. Lurier, Elodie Rousset, Patrick Gasqui, Carole Sala, Clément Claustre, et al.. Evaluation using latent class models of the diagnostic performances of three ELISA tests commercialized for the serological diagnosis of Coxiella burnetii infection in domestic ruminants. Veterinary Research, 2021, 52 (1), ⟨10.1186/s13567-021-00926-w⟩. ⟨hal-03198853⟩