Evaluation of the sensitivity and specificity of the lateral flow assay, Rose Bengal test and the complement fixation test for the diagnosis of brucellosis in cattle using Bayesian latent class analysis

Davies M Pfukenyi; Eleftherios Meletis; Boitumelo Modise; Masimba Ndengu; Faith W Kadzviti; Kopano Dipuo; Kago Moesi; Polychronis Kostoulas; Gift Matope

doi:10.1016/j.prevetmed.2020.105075

Evaluation of the sensitivity and specificity of the lateral flow assay, Rose Bengal test and the complement fixation test for the diagnosis of brucellosis in cattle using Bayesian latent class analysis

Prev Vet Med. 2020 Aug:181:105075. doi: 10.1016/j.prevetmed.2020.105075. Epub 2020 Jun 21.

Authors

Davies M Pfukenyi¹, Eleftherios Meletis², Boitumelo Modise³, Masimba Ndengu¹, Faith W Kadzviti⁴, Kopano Dipuo³, Kago Moesi³, Polychronis Kostoulas², Gift Matope⁵

Affiliations

¹ Department of Clinical Veterinary Studies, Faculty of Veterinary Science, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe.
² Laboratory of Epidemiology, Biostatistics and Animal Health Economics, Faculty of Veterinary Medicine, University of Thessaly, Karditsa, 224 Trikalon St., Greece.
³ Botswana National Veterinary Laboratory, Private Bag 0035, Gaborone, Botswana.
⁴ Department of Paraclinical Veterinary Studies, Faculty of Veterinary Science, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe.
⁵ Department of Paraclinical Veterinary Studies, Faculty of Veterinary Science, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe. Electronic address: giftmatope@gmail.com.

PMID: 32622242
DOI: 10.1016/j.prevetmed.2020.105075

Abstract

This study was conducted to evaluate the sensitivity (Se) and specificity (Sp) of the Rose Bengal test (RBT), complement fixation test (CFT), the serum lateral flow assay (LFA_serum) and the blood lateral flow assay (LFA_blood) for the detection of antibodies to Brucella spp. using Bayesian latent class models (BLCMs). Sera and whole blood were collected from naturally infected cattle reared in smallholder, small-scale commercial and large-scale commercial farms in Zimbabwe (n = 1022) and Botswana (n = 770). The BLCMs were fitted under the assumption that conditional dependences existed between the tests. Based on the conditional dependence model, the RBT had the highest Se of 0.897 (95 % Probability Intervals: 0.854; 0.932) compared to 0.827 (0.773; 0.872), 0.812 (0.76; 0.858) and 0.809 (0.785; 0.832) for the LFA_serum, LFA_blood and CFT, respectively. The CFT recorded a higher Sp of 0.999 (0.995; 1.000) than the LFA_serum 0.996 (0.99; 1.000), the LFA_blood 0.984 (0.976; 0.991) and the RBT 0.969 (0.959; 0.978). The data indicated that both the Se and Sp of RBT and CFT and the Sp of LFA_serum and LFA_blood were conditionally independent, while the Se appeared to be conditionally dependent. These results indicated that none of the evaluated tests had perfect Se and Sp and consequently could not be used alone for the diagnosis of brucellosis in cattle from the studied farming sectors. Thus, based on high Se and Sp, respectively, a brucellosis testing regimen using the RBT (screening) and the LFA (confirmatory) may be considered.

Keywords: Brucellosis; CFT; Cattle; Latent class analysis; Lateral flow assay; RBT.

Publication types

Comparative Study

MeSH terms

Animals
Bayes Theorem
Blood Chemical Analysis / veterinary*
Botswana
Brucellosis, Bovine / diagnosis*
Cattle
Complement Fixation Tests / veterinary*
Latent Class Analysis
Rose Bengal / chemistry*
Sensitivity and Specificity
Zimbabwe

Substances

Rose Bengal